This is why I love your videos. You set out on a task and let the results take you where they lead, rather than trying to land where you think they should land. I saw a recent video of a “test” where the results/data weren’t even shown in the video but rather an answer was given that was obvious that that’s where they wanted to go regardless. Appreciate your work and honesty.
I guess the moral of this story is: apply enough pressure to do the job, and nothing more. Going nuts cranking on it does nothing good but warp things needlessly. Great content as always! Keep 'em coming!
I've been using Pony pipe clamps for panel glue ups throughout my 50 years of woodworking. I've also used the Bessey clamps extensively and they also work great. If you machine the wood correctly, be aware of the growth ring direction, and clamp on alternate sides, nearly any clamp will do the job. Using some hardwood cauls with cello tape on the faces helps keep things straight and even as well. For the price of one Bessey parallel clamp you can 2 or 3 pipe clamps, and one rule about clamping is- You Can Never Have Enough!
As an OG woodworker (64 yrs. old) I'll stick to my 40 or 50 Pony pipe clamps. I do have about 10 or 12 I-beam style bar clamps, but only because I found them at flea markets at prices too good to ignore. A+ is your grade for reminding us all of the real secret-- "Wood HAS to move".
Thank you for verifying my own observation about bowing. I had trouble keeping panels flat and resorted back to my pipe clamps. But, after some investigating, I noticed the bowing and began using the parallel clamps again, but I turn them side-ways. Problem disappeared. Another stellar video.
On thin panels, I lay the clamps on their sides. This way you get the full length of the head making contact which reduces indentations and your bar deflection is parallel to the panel instead of pushing against it.
This is why you will continue a long and successful career as a Woodworking Master Craftsman. Not only can you build the complex and beautiful stuff, you know how to convey woodworking technique, and science to your audience. Not just answering the how-to, but also the why. I especially love when you dispell myths and old wives tales. Another one bites the dust!😂 thanks
Structural engineer here and I approve this message. I deal with forces and deflections every day and most of this is bang on. A few further notes: -Everything moves under force, how much depends on the stiffness (material and geometry) and the stiffness of other parts. The “flattening” of the jaws depends on the stiffness of the jaws, jaw-bar connection, bar, and even the stiffness of what’s being clamped. -Just because the jaw is flat after clamping doesn’t mean even pressure across the jaw. Uneven pressure alone causes the clamp up to bow. To get even pressure across the jaws would mean precise engineering work, with the exact right clamping force, and would depend on the wood stiffness which means it’ll be different for not just different species, but even the natural variability of wood from the same tree. -Thin and wide panel glue ups are likely to buckle under load. Even if perfectly even pressure was applied without the clamp inducing any bow into the panel, it can still bow from buckling. My advice: use whatever clamps you want, with cauls to control bowing. Cauls effectively increase the stiffness of the panel temporarily and significantly reduce any effects from clamping. As for cauls, the stiffer (hardwood/metal or deeper sections) the better
I've been gluing up a lot of 24 inch boards over the past couple of weeks and see exactly what you're saying here. I've been tightening enough for the joint to close and see squeeze out, then backing them off to where they are barely putting any pressure on. All panels came out very well and not a single gap in the joints
I was thinking the same thing… but to impart knowledge you actually have to have the knowledge in the first place which he definitely doesn’t! He just plays a woodworker on TH-cam lol.. just do the opposite of what he says/does and you’ll be ok. He just peddles tools that he has no idea how to use and ppl eat it up!
Man, he always 'reviews' a bunch of products he got online by just looking at them and going "eh, probably not that great" without even using them once! Such a grifter.
There is an extremely important lesson here that somewhat gets glossed over. YOU DO NOT NEED A LOT OF PRESSURE IF EVERYTHING IS MILLED CORRECTLY. trying to bend your board to fit will only create disaster later. Thanks Mark, great video!
@@barryomahony4983 I think most people do not really know how much turning pressure on the clamp equates to 100-250 psi. I think that is where the problem really lies. The mechanical advantage of the screw greatly reduces the effort required to turn it to achieve the desired clamping pressure.
Absolutely the best video I’ve seen on the physics of clamping. The coverage of toe-in dispelled some bad information circulating on YT while the alternating clamp position solution (right side up, upside down) was highly constructive towards solving the issue of bar inversion. Thank you!
Pro-tip: lift your panels using cauls so that they’re not resting on the bar of the clamp. That keeps the deflecting bar from pushing against the panel (and will keep glue off your clamps). Also: As Marc does, alternating clamp location from top to bottom is DEFINITELY good practice. You can even “tune” the flatness of the panel by adjusting the pressure of the top and bottom clamps accordingly.
Excellent, thanks Mark! So refreshing to see this after I made the mistake of watching some....um...less competent reviews! I always sit my boards on clamping cauls slightly above the level of the bars, so the deflection of the bars has no bearing on the geometry of the panels. The trick is the find the clamping force sweet spot that only drives the front and back parallel and not beyond, but like you say, many folks clamp too hard. Great video.
I added a Fulton Panel Max Glue Press System in one corner of the shop years ago and never looked back. it's a primo 4 way panel glue-up clamp system and I've saved a fortune in parallel clamps. Does it all from 0" to 5" stock. Table tops, doors, etc.. YMMV, to each his own, yada yada. That said, great video Marc and it goes w/o saying the key to any successful panel glue-up is to always wear your Wood Whisperer apron during the process.
Hey, Marc! Most clamps come with two plastic clip-on risers that can be used to space the workpiece off of the clamp's bar that will deflect under load (by design, as you describe). They happen to also be a nice non-marring surface and leave a gap to clean up glue that squeezes out. Thanks for making great videos and helping us all become better woodworkers! - Colin
Marc, thank you for this heaping helping of common sense. You stepped back, took a deep breath, and looked past brand and spec hype to determine and explain the basic why and how of parallel clamp function. I don't have any parallel clamps yet, but this video will help greatly in my decision making process as to if and which clamps I should consider.
I personally like that most parallel clamps are pretty consistent in quality across brands and a good step up from the cheap-o clamps a lot of folks start out with. Plus the wide jaws on both sides are nicer to work with than f-clamps in a lot of furniture projects. But they're not magic and I definitely noticed they weren't perfect for thinner panels. Nice to get a good concise explanation.
Thanks Marc. Having watched a few of those other reviews, I couldn’t help but scratch my head. However, I couldn’t name the deficits or false assumptions, I just knew it didn’t feel as though they were assessing any meaningful differences. I always leave your videos armed with information. Much appreciated
Outstanding. I've watched some of the reviews you're likely referring to because I wanted to know what I don't know about the various brands. This video is a great example of your content; the educators I looked to could/should learn a thing or two from this. Your work and content are helping myself and thousands of other woodworkers every day. Keep up the phenomenal work!
I took the 3 month course at the Center for Furniture Craftsmanship in Maine. They taught us to lay the boards we were gluing on the edge of two 2 by 4's that had been planed and jointed square. This raised the wood about 3" off the bench. The clamps rested on the bench so the jaws of the clamps engaged the wood about 3" above the bench. This did not allow the bending of the bar of the clamp to touch the wood.
Great analysis/information and thanks for sharing. I have an engineering background, but started woodturning about a year ago. I built a threading jig to cut threads in lidded boxes. You are not wrong when you say that wood moved. On some boxes the threads were quite loose when they were cut. 6 months later and some lids dont screw on anymore.
Another top-notch video. Excellent presentation with an excellent explanation of what you find, why you found it important, and why it matters (or should matter) to us. Plus, it was educational for our wood workshop process!! Piece of trivia: years ago, when I was looking for a bench vice, I was looking FOR that toe-in. What shocked me most was that Jorgenson's bench vice did not have any toe-in; the faces were absolutely perpendicular. I ended up with the Lee Valley and have been very pleased with the quality and performance. The LV toe-in was perfect. (BTW, I love the T-shirt.)
Thank you for saving me the money I was going to spend on the therapist to cure my neurosis relative to bowing my panels under clamping pressure! It gives me comfort to know I am not the only woodworker cringing the bow and we have to accept some deviation that no one will notice.
This was helpful! I just did a small panel glue up recently and used parallel clamps and it wasn’t flat, I was convinced I was doing something wrong. I was able to flatten it again without messing things up, but it’s nice to know that I wasn’t doing anything wrong!
I'm curious to think of the way I use the clamps. On thinner glue-ups I set the parallel clamps down sideways to keep your stated deflection at a minimum. Another great video! Thanks for all of the helpful information!
Excellent balance. I don't think you can beat pipe clamps for a cost/value for thin panel glue-ups. 3/4" pipe clamps tightened to 150lbs only have a couple thou deflection, and that's more than enough pressure for most 1/4"-3/4" panels in my experience.
Funny that you mentioned this. I noticed during your cutting board video you talked about the pressure needed for a successful joint. I just used that process in my last three glue-ups. I know I’ve used way too much pressure in the past. Thanks
This is a really informative video. I learned some things about parallel clamps that I never knew. Once you went through how they work and why the jaws are toed in, it totally makes sense that panels will not be flat if they are only clamped from the bottom and a fair amount of pressure put on the them. It also makes sense that alternating the clamps top and bottom in theory might keep them flat. I have some aluminum bar clamps from Rockler that I use on the bottom of my panels with F-style and/or parallel clamps that I put on top. So far, that seems to work for me pretty well, but I'm usually clamping up thicker material for cutting boards, etc. so they probably are less prone to bowing anyway.
One thing I like about parallel clamps for panels is that I can turn them on their side so the entire face of the clamp is in contact with the wood. They all have a pretty decent shoulder so you can even do this to 90° but I usually end up at a steep angle to maximize the contact area and distribute the force a bit more evenly from top to bottom (though I also try clamp top and bottom to even things out that way). Another GREAT use for these is just to pull/hold pieces together. They make a great second set of hands for holding panels together when dry fitting or gluing, and are easily strong enough to pull/hold larger beams (like the leg assembly on my roubo bench) into alignment with far more precision than you get using a mallet.
I am getting back into woodworking and watching videos. I was jealous of people who could use parallel clamps in a glue up, and then just stand the assembly in the corner, out of the way to cure. I am glad I found your review and thoughts.
When i saw the other video, like you, I was wondering why the squareness of the jaw was so important, it did not make sens eto me. So, Thank you very much for agreeing with me!!! LOL As usually, very informative, transparent and fun.
Excellent video. I never thought much about how the clamps work before. Makes me think that in narrow panel glue ups maybe F style clamps would be just as effective. Wonder?
Great info, and it explains much! I've been involved in making sawdust in some form or another for over half a century and ALWAYS love learning something new! Speaking of which... Might you consider doing a video on gluing? (Please point me in the right direction if you've already done so, but I haven't found one.) I know what my stepfather taught me about how to glue two pieces of wood together, but I see a myriad of different processes in the TH-cam world. It's made me wonder, what exactly IS the best way? Should I be applying glue to both pieces or is one side enough? Should it be a thin, semi-transparent coat or slathered on? Should it completely cover the joint or can it be applied and let the clamps spread it out? How much force should I used? How much squeeze-out should I have... and what's the best method of dealing with that squeeze-out? Should I scrape it, or does that risk marring the wood too much? Should I wipe it with a wet rag, or does that moisture affect the joint (as I've seen someone declare)? And what about salt? I've even seen one person say he puts a human hair between pieces to ensure he doesn't over-squeeze the joint. I--and others, I'm sure--would greatly appreciate your thoughts on this important subject! Thanks again!
Well made video informative for pros and amateurs alike. I’m a pro and get bored with all the beginner focused stuff on TH-cam but this was great. Bravo.
Thanks Mark, a very well thought video :) When I start digging into the parallel clamp department, I did watch and read a ton about it. At the time I was fortunate enough to work at 10 minutes drive from Leel Valley HQ. They were not selling the Bessey one but the Ehoma instead. Comparing both prices the Ehoma were like 30% cheaper so it was a no brainer to me. Looking back today, L.V. are selling both brand and the Bessey are now cheaper 🤣
Great video as always, but OMG...I've never seen a T-shirt more aptly describe my current situation! Keep up the amazing work Marc, I'm off to stock up on Ensure.
I started making basic panels before parallel clamps became available in my part of the world and I quickly learnt the over-under routine - luckily in those days I had good reflexes so I managed to avoid being hit in the head by pieces of panel being ejected at speed when I cranked down on the clamp handles. Then came Bessey, and I had to ease up again as I was crushing the edges of the panels where the clamps where - like visible, square dents in the wood just a bit under 1/16" deep (plantation grown pine). These days I'm using Bessey DuoClamps (and a few Irwin QuickGrip these days) for most of the smaller jobs - adequate clamping pressure and much lighter so I can more easily move and stack panels with several clamps attached while the glue dries. Still got a few dozen Bessey parallel clamps on the rack though.
Being a woodworker with a very small tool budget, my clamp collection consists of two 6 foot pipe clamps and two 4 foot bar clamps from Harbor Freight that I gave the Paul Sellers treatment. Work great for me.
Thank you so much! As always, you give a considered and thoughtful viewpoint. I no longer feel the need to rush and get parallel clamps (I picked up some pipe clamps to get me started)
I love your honesty. Tell your sponsors I’ll buy anything you recommend 😊 Love the extra animations. So much good info in this video. Tiny quibble, I don’t think that brand x being rated at 1000# and y being rated at 1700# means you are getting those numbers at “star” torque. I think it means if you rig a wrench and cheater bar and actually hit 1000# then brand x is gonna blow up. I would be surprised if my old method of cranking till the handle won’t move is above 500#. As far as I am concerned brand x and y have same mechanical advantage at the handle.
BS in Mechanical Engineering here. I'm 63 and have only bar and F-clamps, never could figure out what the advantage is in a "parallel" clamp so never bought any. You've very much confirmed my suspicions, thank you!
At first I thought this video subject would be somewhat boring but as it progressed, I saw some real knowledge nuggets pop up. I was actually going to shell out perhaps $600 for about ten K-body clamps but now I realize that my bar clamps are just fine for my typical work. I now have $600 to put toward something more useful. Many Thanks Mark!
I'm going to be making some table tops in the future and I didn't own any parallel clamps at the time. I actually got two of the Rockler panel clamps and several parallel clamps. My plan is to use them together. Hopefully resulting in nice flat panels without any gaps
Like you said Mark, once the gap closes, that's when I stop. Usually it's very little force and I usually tighten with my fingers not a fist. I only own Bessey clamps so I cannot speak to any other clamp manufacturer. None of the furniture I've built has come unglued yet! I might be a rebel though, I built my crosscut sled using a square instead of the 5-cut method.
Thanks for the great video. In my shop i use parallel clamps for clamping casegoods or drawers; things that need to be clamped square, not necessarily flat. When using traditional clamps for case glueups, if the clamp isn’t perfectly straight it will pull a box out of square. The parallel clamps align on the box very easily and keeps things square.
Marc, thank you for the insight. So basically they all work well, if you feel you have to squeeze these clamps to death maybe go back and check your milling techniques. Awesome info man!
I started out 50 years ago and had some Jorgensen bar clamps. Got some additional bar clamps and have always expected wood to move. I'll keep my clamps...
I'm planning on making a dining table for my house, but I currently only own 2 squeeze clamps. This info is very helpful in helping me know what to look for.
Thank you for primarily using the correct term, Force and not calling everything clamping pressure...drives me nuts. Pressure requires knowing the area 🤓. I keep alternating the clamps or i lay them sideways sometimes so the entire head is engaged woth the thin pannel. Not sure if it helps but seems worth a shot sometimes. Not over clamping is probably some of the best advice, if you have to crank too hard there could be another issue going on.
Great video as usual! I've been watching for years but i believe this is my first comment. I've always wanted to have a army of parallel clamps but as a hobbyist/amateur wood worker who does sell a few things from time to time, I could never justify the cost. I have a bunch of pipe clamps that really do the job nicely. I bought them used and the cost/savings is dramatically better than buying parallel clamps. This isn't saying I have never used parallel clamps to glue up panels, because I have. However, I lay the clamp down flat on it's side. They are wide enough grab onto 3/4" boards while in this position which allows the entire head to be in contact with the panel. How do you feel about this Marc?
Good question. I do the same with panels & tend to knky have the parallel clamp upright if I am gluing together boxes or bookcases or something else with depth.
I’m glad you pointed out the issue with parallel clamps with glue ups. I see this in my shop and I usually opt for bar clamps over parallel clamps and I always thought my clamps were bad or I just wasn’t doing it right
Funny, I had always said I'd never buy parallel clamps. The world got by just fine without them. Then, I had a specific glue up and buying 6 of them seemed like a good idea. I've since bought more. The BIGGEST thing I don't like about parallel clamps is that the operating side is the adjustable side. So, using a long clamp is a PITA. I've also found in clamping panels that I prefer pipe clamps and clamping both sides to equalize pressure because it's always worked (sorta like hoping for a loose french fry or two in the bottom of the bag has always worked, no real evidence). I've bought two brands, one expensive and one cheap. I'll be buying more of a specific cheap brand when they're on sale. Good info Marc.
I always considered doing similar tests, but after 20yrs, I guess I didn't. However I do have a pressure gauge and tested many of the makes, and they range from 500 to 1500 psi in psi. Quite the variance. Those I Beam Bessyes, prob. overkill for panels. Some simple and useful information you have provided, as u always do. No reason to over complicate a subject. I use heavy duty alum. bars the size of 2x4's, across the joints, and clamp those down on critical large panel glues ups, a little extra work, but it works, but surely PITA and they are heavy! I recently bought the Rocker panel clamps, have not used them yet, but question if you apply enough force if the panel stays flat. IMO, the real key is... tune up your jointer, get straight edges on your boards and glue up immediately before the wood moves. If you have a FLAT table top surface, you can use rub joints, (no clamps) and there is no gaps. A great strategy especially with very thin boards. As you mention, really thin boards really want to buckle under pressure. High pressure is required to close gaps, a result of non straight jointed edges. As we agree, one size does not fit all in ww. Use the strategy that makes the most sense for the application in front of you. Well done video...
Thanks Marc, had no idea Bessey made those I beam clamps. Also thanks for the low down on the K body clamps. I have a bunch and never thought about the whole parallel thing but I don’t apply a ton of pressure usually, but great to know before I had a chance to stress over it ! Lol
You bring up a good point about not having to go "He-Man" on the clamps. I've made the mistake of cranking it down too hard, which caused cupping during the glue up which I didn't see until later. Lesson learned - just enough pressure, no more.
Thanks Marc, always a pleasure to follow your videos and helpful as well. I made the same experiences:before, during and after clamping... wood is a living material :)
Oh yeah, I remember years ago when I bought my first parallel clamps and, being a machinist, checking them for square. Then being unhappy because they were, of course, not square. Eventually learned what you are so eloquently explaining here, that they are not supposed to be square. Going from the Tool & Die world into woodworking was quite the change for me, precision-wise. I've learned to adapt - meaning I'm much more forgiving now.
Interesting thoughts about the clamps, thank you, I've started to realise over the last few years that parallel clamps are likely to be over hyped, the main thing I like about them is you don't need to worry where on the head you're clamping as long as it's the same on both ends. A couple of thoughts about possible tests: Necessary force applied to obtain even force applied at the top and bottom of the head. (require 2 load cells and you can also check what loads you generally need to close up a joint) What torque you need to apply to achieve the above force and the torque for a pre designated force (say 500N). The diameter of the handle and whether the handle flips down horizontally to help apply the necessary force to draw the faces parallel. How much the bar deflects when the faces are parallel and when say 500N of force is being generated. Longevity, whether head starts to slip after 100,1000 clamp and releases (sorry this is going to be very boring) Whether the bars rust when PVA glue is left on them for a couple of days. Whether the clamps still work or are damaged when dropped 10 times from a bench height. Clamp face width and depth. Obviously some of the tests would require some explaining why they're not valid in certain circumstances. Hopefully that's vaguely helpful :)
A well-prepared piece of wood for a panel needs very little pressure. When I did production work, I used I-Bar clamps (I had over two hundred.) I now use nothing but Rockler aluminum bar clamps. Don't have the grip in my hands for parallel clamps. Great video.
Is it the case that perhaps pipe clamps are a better choice for panel glue ups? There isn’t the same downward force on the ends as with bar clamps but there should be zero deflection in the middle. Alternating (up and downward facing) pipe clamps should negate the need for downward force. Thoughts?
Fantastic insight! I think a lot of folks gravitate towards parallel clamps because they are the precieved "premium" clamp. A well equipped shop really should have a variety of clamp types. I don't understand why the venerable pipe clamp doesn't get more credit.
My mistake has always been using parallel clamps for cabinet carcass glue ups. What Mark shows at 2:22 tends to deform the side of my cabinet before it puts pressure on the joint.
@@spycedezynuk i second this, and is actually what Bessey reccomends. Use the side of the clamp / turn it 90 degrees. I suppose this also works for thin panels.
Thanks for the honest enlightening results. The more panel clamping videos I see, the more I think that 4 direction panel clamps are superior though underutilized.
as a retired furniture maker i obviously never had parallel clamps back in the day. i have looked at them and thought they look good until i saw the price lol. i spent my working life using the old bar clamps which had very little deflection unless you over tightened them. when applying clamps you need to do the old over under to keep the panel nice and level and increase the pressure slowly with a bit on each clamp before applying yet more pressure. and you are right, most people over clamp their work.
This is why I love your videos. You set out on a task and let the results take you where they lead, rather than trying to land where you think they should land. I saw a recent video of a “test” where the results/data weren’t even shown in the video but rather an answer was given that was obvious that that’s where they wanted to go regardless. Appreciate your work and honesty.
Nothing worse than “reviews” that are almost word for word of the on-line ads.
@@willowspringhill8349 Amen!
I guess the moral of this story is: apply enough pressure to do the job, and nothing more. Going nuts cranking on it does nothing good but warp things needlessly. Great content as always! Keep 'em coming!
I've been using Pony pipe clamps for panel glue ups throughout my 50 years of woodworking. I've also used the Bessey clamps extensively and they also work great. If you machine the wood correctly, be aware of the growth ring direction, and clamp on alternate sides, nearly any clamp will do the job. Using some hardwood cauls with cello tape on the faces helps keep things straight and even as well. For the price of one Bessey parallel clamp you can 2 or 3 pipe clamps, and one rule about clamping is- You Can Never Have Enough!
As an OG woodworker (64 yrs. old) I'll stick to my 40 or 50 Pony pipe clamps. I do have about 10 or 12 I-beam style bar clamps, but only because I found them at flea markets at prices too good to ignore. A+ is your grade for reminding us all of the real secret-- "Wood HAS to move".
Thank you for verifying my own observation about bowing. I had trouble keeping panels flat and resorted back to my pipe clamps. But, after some investigating, I noticed the bowing and began using the parallel clamps again, but I turn them side-ways. Problem disappeared. Another stellar video.
I’m a sideways guy too I feel like they work much better that way and any deflection is going laterally 👍🏻
Same. Always sideways with panels, vertical if doing a box or bookcase.
Does this work for deep panels? Can you put a clamp down the middle of the panel sideways?
On thin panels, I lay the clamps on their sides. This way you get the full length of the head making contact which reduces indentations and your bar deflection is parallel to the panel instead of pushing against it.
Thanks for the tip
This is what I do too😊
I do the same. A lot more clamp engaged with the panel.
Same
And I don't have to worry about the clamp tipping over while I am positioning my workpiece.
This is why you will continue a long and successful career as a Woodworking Master Craftsman. Not only can you build the complex and beautiful stuff, you know how to convey woodworking technique, and science to your audience. Not just answering the how-to, but also the why. I especially love when you dispell myths and old wives tales. Another one bites the dust!😂 thanks
Structural engineer here and I approve this message. I deal with forces and deflections every day and most of this is bang on. A few further notes:
-Everything moves under force, how much depends on the stiffness (material and geometry) and the stiffness of other parts. The “flattening” of the jaws depends on the stiffness of the jaws, jaw-bar connection, bar, and even the stiffness of what’s being clamped.
-Just because the jaw is flat after clamping doesn’t mean even pressure across the jaw. Uneven pressure alone causes the clamp up to bow. To get even pressure across the jaws would mean precise engineering work, with the exact right clamping force, and would depend on the wood stiffness which means it’ll be different for not just different species, but even the natural variability of wood from the same tree.
-Thin and wide panel glue ups are likely to buckle under load. Even if perfectly even pressure was applied without the clamp inducing any bow into the panel, it can still bow from buckling.
My advice: use whatever clamps you want, with cauls to control bowing. Cauls effectively increase the stiffness of the panel temporarily and significantly reduce any effects from clamping. As for cauls, the stiffer (hardwood/metal or deeper sections) the better
Once again setting the bar for this kind of educational material. I just wish other channels did the same in parallel.
I see what you did there
@@robertpenn2152 Ghaleon is clearly a straight shooter.
@@robertpenn2152 your thoughts are on the same plane.
i see you.
You win.
I've been gluing up a lot of 24 inch boards over the past couple of weeks and see exactly what you're saying here. I've been tightening enough for the joint to close and see squeeze out, then backing them off to where they are barely putting any pressure on. All panels came out very well and not a single gap in the joints
731 should watch this. He could learn a lot. His channel has become just a bunch of sales videos, not imparting real knowledge like this.
It’s become safe to draw the opposite conclusions from him based on his tests lately (sawstop and parallel clamps being the main culprits)
I was thinking the same thing… but to impart knowledge you actually have to have the knowledge in the first place which he definitely doesn’t! He just plays a woodworker on TH-cam lol.. just do the opposite of what he says/does and you’ll be ok. He just peddles tools that he has no idea how to use and ppl eat it up!
Man, he always 'reviews' a bunch of products he got online by just looking at them and going "eh, probably not that great" without even using them once! Such a grifter.
He’s a bullshit artist.
There is an extremely important lesson here that somewhat gets glossed over. YOU DO NOT NEED A LOT OF PRESSURE IF EVERYTHING IS MILLED CORRECTLY. trying to bend your board to fit will only create disaster later. Thanks Mark, great video!
@@barryomahony4983 I think most people do not really know how much turning pressure on the clamp equates to 100-250 psi. I think that is where the problem really lies. The mechanical advantage of the screw greatly reduces the effort required to turn it to achieve the desired clamping pressure.
Absolutely the best video I’ve seen on the physics of clamping. The coverage of toe-in dispelled some bad information circulating on YT while the alternating clamp position solution (right side up, upside down) was highly constructive towards solving the issue of bar inversion. Thank you!
Pro-tip: lift your panels using cauls so that they’re not resting on the bar of the clamp. That keeps the deflecting bar from pushing against the panel (and will keep glue off your clamps).
Also: As Marc does, alternating clamp location from top to bottom is DEFINITELY good practice. You can even “tune” the flatness of the panel by adjusting the pressure of the top and bottom clamps accordingly.
2 and a half mins in and I'm mind blown already, now to watch the rest of the surely awesome info! Thanks Marc!!
Excellent, thanks Mark! So refreshing to see this after I made the mistake of watching some....um...less competent reviews! I always sit my boards on clamping cauls slightly above the level of the bars, so the deflection of the bars has no bearing on the geometry of the panels. The trick is the find the clamping force sweet spot that only drives the front and back parallel and not beyond, but like you say, many folks clamp too hard. Great video.
I added a Fulton Panel Max Glue Press System in one corner of the shop years ago and never looked back. it's a primo 4 way panel glue-up clamp system and I've saved a fortune in parallel clamps. Does it all from 0" to 5" stock. Table tops, doors, etc.. YMMV, to each his own, yada yada. That said, great video Marc and it goes w/o saying the key to any successful panel glue-up is to always wear your Wood Whisperer apron during the process.
Hey, Marc! Most clamps come with two plastic clip-on risers that can be used to space the workpiece off of the clamp's bar that will deflect under load (by design, as you describe). They happen to also be a nice non-marring surface and leave a gap to clean up glue that squeezes out. Thanks for making great videos and helping us all become better woodworkers! - Colin
My rocker parallel clamps didn’t come with these. Is there a cheap one to buy or an easy one to make?
Marc, thank you for this heaping helping of common sense. You stepped back, took a deep breath, and looked past brand and spec hype to determine and explain the basic why and how of parallel clamp function. I don't have any parallel clamps yet, but this video will help greatly in my decision making process as to if and which clamps I should consider.
I personally like that most parallel clamps are pretty consistent in quality across brands and a good step up from the cheap-o clamps a lot of folks start out with. Plus the wide jaws on both sides are nicer to work with than f-clamps in a lot of furniture projects. But they're not magic and I definitely noticed they weren't perfect for thinner panels. Nice to get a good concise explanation.
Thanks Marc. Having watched a few of those other reviews, I couldn’t help but scratch my head. However, I couldn’t name the deficits or false assumptions, I just knew it didn’t feel as though they were assessing any meaningful differences. I always leave your videos armed with information. Much appreciated
Outstanding. I've watched some of the reviews you're likely referring to because I wanted to know what I don't know about the various brands. This video is a great example of your content; the educators I looked to could/should learn a thing or two from this. Your work and content are helping myself and thousands of other woodworkers every day. Keep up the phenomenal work!
That was the best explanation of clamps I’ve seen. The best part though was your tee shirt. I love it!!!
I took the 3 month course at the Center for Furniture Craftsmanship in Maine. They taught us to lay the boards we were gluing on the edge of two 2 by 4's that had been planed and jointed square. This raised the wood about 3" off the bench. The clamps rested on the bench so the jaws of the clamps engaged the wood about 3" above the bench. This did not allow the bending of the bar of the clamp to touch the wood.
Great analysis/information and thanks for sharing. I have an engineering background, but started woodturning about a year ago. I built a threading jig to cut threads in lidded boxes. You are not wrong when you say that wood moved. On some boxes the threads were quite loose when they were cut. 6 months later and some lids dont screw on anymore.
Always love watching your perspective. Thank you as Always Marc!
Another top-notch video. Excellent presentation with an excellent explanation of what you find, why you found it important, and why it matters (or should matter) to us. Plus, it was educational for our wood workshop process!! Piece of trivia: years ago, when I was looking for a bench vice, I was looking FOR that toe-in. What shocked me most was that Jorgenson's bench vice did not have any toe-in; the faces were absolutely perpendicular. I ended up with the Lee Valley and have been very pleased with the quality and performance. The LV toe-in was perfect. (BTW, I love the T-shirt.)
Thank you for saving me the money I was going to spend on the therapist to cure my neurosis relative to bowing my panels under clamping pressure! It gives me comfort to know I am not the only woodworker cringing the bow and we have to accept some deviation that no one will notice.
Thank you somebody finally pointed out that the clamps become parallel when they are under pressure. Not when just sitting on the bench!!!!
This was helpful! I just did a small panel glue up recently and used parallel clamps and it wasn’t flat, I was convinced I was doing something wrong. I was able to flatten it again without messing things up, but it’s nice to know that I wasn’t doing anything wrong!
I'm curious to think of the way I use the clamps. On thinner glue-ups I set the parallel clamps down sideways to keep your stated deflection at a minimum. Another great video! Thanks for all of the helpful information!
Excellent balance. I don't think you can beat pipe clamps for a cost/value for thin panel glue-ups. 3/4" pipe clamps tightened to 150lbs only have a couple thou deflection, and that's more than enough pressure for most 1/4"-3/4" panels in my experience.
Why do you always have to challenge my preconceived notions?
Funny that you mentioned this. I noticed during your cutting board video you talked about the pressure needed for a successful joint. I just used that process in my last three glue-ups. I know I’ve used way too much pressure in the past. Thanks
Another amazingly educational video! I really appreciate and enjoy your approach to subjects like these 👍
This is a really informative video. I learned some things about parallel clamps that I never knew. Once you went through how they work and why the jaws are toed in, it totally makes sense that panels will not be flat if they are only clamped from the bottom and a fair amount of pressure put on the them. It also makes sense that alternating the clamps top and bottom in theory might keep them flat. I have some aluminum bar clamps from Rockler that I use on the bottom of my panels with F-style and/or parallel clamps that I put on top. So far, that seems to work for me pretty well, but I'm usually clamping up thicker material for cutting boards, etc. so they probably are less prone to bowing anyway.
I too have seen videos that say the clamp is not square and put a square to prove it. Good teacher and video, thanks.
This is a really good explanation, Marc. I appreciate learning something new every video.
Shoot, 12 or 13 years ago I bought the dewalt track saw based partly on your review, and it still works like a charm. Keep up the great work!
One thing I like about parallel clamps for panels is that I can turn them on their side so the entire face of the clamp is in contact with the wood. They all have a pretty decent shoulder so you can even do this to 90° but I usually end up at a steep angle to maximize the contact area and distribute the force a bit more evenly from top to bottom (though I also try clamp top and bottom to even things out that way). Another GREAT use for these is just to pull/hold pieces together. They make a great second set of hands for holding panels together when dry fitting or gluing, and are easily strong enough to pull/hold larger beams (like the leg assembly on my roubo bench) into alignment with far more precision than you get using a mallet.
I am getting back into woodworking and watching videos. I was jealous of people who could use parallel clamps in a glue up, and then just stand the assembly in the corner, out of the way to cure. I am glad I found your review and thoughts.
When i saw the other video, like you, I was wondering why the squareness of the jaw was so important, it did not make sens eto me. So, Thank you very much for agreeing with me!!! LOL
As usually, very informative, transparent and fun.
Excellent video. I never thought much about how the clamps work before. Makes me think that in narrow panel glue ups maybe F style clamps would be just as effective. Wonder?
Great info, and it explains much! I've been involved in making sawdust in some form or another for over half a century and ALWAYS love learning something new! Speaking of which...
Might you consider doing a video on gluing? (Please point me in the right direction if you've already done so, but I haven't found one.) I know what my stepfather taught me about how to glue two pieces of wood together, but I see a myriad of different processes in the TH-cam world. It's made me wonder, what exactly IS the best way?
Should I be applying glue to both pieces or is one side enough? Should it be a thin, semi-transparent coat or slathered on? Should it completely cover the joint or can it be applied and let the clamps spread it out? How much force should I used? How much squeeze-out should I have... and what's the best method of dealing with that squeeze-out? Should I scrape it, or does that risk marring the wood too much? Should I wipe it with a wet rag, or does that moisture affect the joint (as I've seen someone declare)? And what about salt? I've even seen one person say he puts a human hair between pieces to ensure he doesn't over-squeeze the joint. I--and others, I'm sure--would greatly appreciate your thoughts on this important subject! Thanks again!
Well made video informative for pros and amateurs alike. I’m a pro and get bored with all the beginner focused stuff on TH-cam but this was great. Bravo.
Thanks Mark, a very well thought video :)
When I start digging into the parallel clamp department, I did watch and read a ton about it. At the time I was fortunate enough to work at 10 minutes drive from Leel Valley HQ. They were not selling the Bessey one but the Ehoma instead. Comparing both prices the Ehoma were like 30% cheaper so it was a no brainer to me. Looking back today, L.V. are selling both brand and the Bessey are now cheaper 🤣
Great video as always, but OMG...I've never seen a T-shirt more aptly describe my current situation! Keep up the amazing work Marc, I'm off to stock up on Ensure.
Your analysis is solid. Thanks for the information.
I started making basic panels before parallel clamps became available in my part of the world and I quickly learnt the over-under routine - luckily in those days I had good reflexes so I managed to avoid being hit in the head by pieces of panel being ejected at speed when I cranked down on the clamp handles. Then came Bessey, and I had to ease up again as I was crushing the edges of the panels where the clamps where - like visible, square dents in the wood just a bit under 1/16" deep (plantation grown pine). These days I'm using Bessey DuoClamps (and a few Irwin QuickGrip these days) for most of the smaller jobs - adequate clamping pressure and much lighter so I can more easily move and stack panels with several clamps attached while the glue dries. Still got a few dozen Bessey parallel clamps on the rack though.
Being a woodworker with a very small tool budget, my clamp collection consists of two 6 foot pipe clamps and two 4 foot bar clamps from Harbor Freight that I gave the Paul Sellers treatment. Work great for me.
Thank you so much! As always, you give a considered and thoughtful viewpoint. I no longer feel the need to rush and get parallel clamps (I picked up some pipe clamps to get me started)
I’m glad this guy speaks. He knows his stuff
I love your honesty. Tell your sponsors I’ll buy anything you recommend 😊
Love the extra animations.
So much good info in this video.
Tiny quibble, I don’t think that brand x being rated at 1000# and y being rated at 1700# means you are getting those numbers at “star” torque. I think it means if you rig a wrench and cheater bar and actually hit 1000# then brand x is gonna blow up. I would be surprised if my old method of cranking till the handle won’t move is above 500#. As far as I am concerned brand x and y have same mechanical advantage at the handle.
BS in Mechanical Engineering here. I'm 63 and have only bar and F-clamps, never could figure out what the advantage is in a "parallel" clamp so never bought any. You've very much confirmed my suspicions, thank you!
At first I thought this video subject would be somewhat boring but as it progressed, I saw some real knowledge nuggets pop up. I was actually going to shell out perhaps $600 for about ten K-body clamps but now I realize that my bar clamps are just fine for my typical work. I now have $600 to put toward something more useful. Many Thanks Mark!
Looks like you've got a firm grasp on the topic
Deep dives like this are the best! Consolidating lots of information and relating it all together is really valuable. Thanks Marc.
I'm going to be making some table tops in the future and I didn't own any parallel clamps at the time. I actually got two of the Rockler panel clamps and several parallel clamps. My plan is to use them together. Hopefully resulting in nice flat panels without any gaps
Like you said Mark, once the gap closes, that's when I stop. Usually it's very little force and I usually tighten with my fingers not a fist. I only own Bessey clamps so I cannot speak to any other clamp manufacturer. None of the furniture I've built has come unglued yet! I might be a rebel though, I built my crosscut sled using a square instead of the 5-cut method.
I love this, Marc. Also, I realize now that I made you a video about my Jet clamp that was slipping and never sent it.
10:48 - I was *SO* anticipating a "Honey Badger don't care" cutaway! Missed opportunity, Marc!
Also, super interesting take on the subject. Thanks!
The music memes in this video are on point. The last one was worth watching til the end!
Thanks for the great video. In my shop i use parallel clamps for clamping casegoods or drawers; things that need to be clamped square, not necessarily flat. When using traditional clamps for case glueups, if the clamp isn’t perfectly straight it will pull a box out of square. The parallel clamps align on the box very easily and keeps things square.
Marc, thank you for the insight. So basically they all work well, if you feel you have to squeeze these clamps to death maybe go back and check your milling techniques. Awesome info man!
I started out 50 years ago and had some Jorgensen bar clamps. Got some additional bar clamps and have always expected wood to move. I'll keep my clamps...
Good review! Much better then other reviews that look at the wrong things.
I'm planning on making a dining table for my house, but I currently only own 2 squeeze clamps. This info is very helpful in helping me know what to look for.
Thank you for primarily using the correct term, Force and not calling everything clamping pressure...drives me nuts. Pressure requires knowing the area 🤓.
I keep alternating the clamps or i lay them sideways sometimes so the entire head is engaged woth the thin pannel. Not sure if it helps but seems worth a shot sometimes. Not over clamping is probably some of the best advice, if you have to crank too hard there could be another issue going on.
I also lay mine sideways.
Great video as usual! I've been watching for years but i believe this is my first comment. I've always wanted to have a army of parallel clamps but as a hobbyist/amateur wood worker who does sell a few things from time to time, I could never justify the cost. I have a bunch of pipe clamps that really do the job nicely. I bought them used and the cost/savings is dramatically better than buying parallel clamps. This isn't saying I have never used parallel clamps to glue up panels, because I have. However, I lay the clamp down flat on it's side. They are wide enough grab onto 3/4" boards while in this position which allows the entire head to be in contact with the panel. How do you feel about this Marc?
Good question. I do the same with panels & tend to knky have the parallel clamp upright if I am gluing together boxes or bookcases or something else with depth.
I’m glad you pointed out the issue with parallel clamps with glue ups. I see this in my shop and I usually opt for bar clamps over parallel clamps and I always thought my clamps were bad or I just wasn’t doing it right
WHAT A VIDEO!! Love the info!!! Thanks mark
I really like your t-shirt, and I enjoyed your attempt at bringing the scientific method to testing parallel clamps.
Funny, I had always said I'd never buy parallel clamps. The world got by just fine without them. Then, I had a specific glue up and buying 6 of them seemed like a good idea. I've since bought more. The BIGGEST thing I don't like about parallel clamps is that the operating side is the adjustable side. So, using a long clamp is a PITA. I've also found in clamping panels that I prefer pipe clamps and clamping both sides to equalize pressure because it's always worked (sorta like hoping for a loose french fry or two in the bottom of the bag has always worked, no real evidence). I've bought two brands, one expensive and one cheap. I'll be buying more of a specific cheap brand when they're on sale. Good info Marc.
I always considered doing similar tests, but after 20yrs, I guess I didn't. However I do have a pressure gauge and tested many of the makes, and they range from 500 to 1500 psi in psi. Quite the variance. Those I Beam Bessyes, prob. overkill for panels. Some simple and useful information you have provided, as u always do. No reason to over complicate a subject.
I use heavy duty alum. bars the size of 2x4's, across the joints, and clamp those down on critical large panel glues ups, a little extra work, but it works, but surely PITA and they are heavy!
I recently bought the Rocker panel clamps, have not used them yet, but question if you apply enough force if the panel stays flat. IMO, the real key is... tune up your jointer, get straight edges on your boards and glue up immediately before the wood moves. If you have a FLAT table top surface, you can use rub joints, (no clamps) and there is no gaps. A great strategy especially with very thin boards. As you mention, really thin boards really want to buckle under pressure. High pressure is required to close gaps, a result of non straight jointed edges.
As we agree, one size does not fit all in ww. Use the strategy that makes the most sense for the application in front of you. Well done video...
I loved this video Marc. This was so educational. Awesome job as always.
Thanks Marc, had no idea Bessey made those I beam clamps. Also thanks for the low down on the K body clamps. I have a bunch and never thought about the whole parallel thing but I don’t apply a ton of pressure usually, but great to know before I had a chance to stress over it ! Lol
Excellent information, and like it that you have specifically mentioned this is your throughts on this.
Thanks for this, I'm always looking to add to my meager supply of clamps. Much appreciated!
You bring up a good point about not having to go "He-Man" on the clamps. I've made the mistake of cranking it down too hard, which caused cupping during the glue up which I didn't see until later. Lesson learned - just enough pressure, no more.
Thanks Marc, always a pleasure to follow your videos and helpful as well. I made the same experiences:before, during and after clamping... wood is a living material :)
Oh yeah, I remember years ago when I bought my first parallel clamps and, being a machinist, checking them for square. Then being unhappy because they were, of course, not square. Eventually learned what you are so eloquently explaining here, that they are not supposed to be square. Going from the Tool & Die world into woodworking was quite the change for me, precision-wise. I've learned to adapt - meaning I'm much more forgiving now.
"good enough" is a phrase to learn in woodworking 😁
i remember when you first started making videos. Your shirt says it all.
My very first thought was "there are 12 brands of parallel clamps? Do we really need that many?". Great video and perspective, as always.
How many came from the same factory?
Thanks! This is extremely helpful!!!
Interesting thoughts about the clamps, thank you, I've started to realise over the last few years that parallel clamps are likely to be over hyped, the main thing I like about them is you don't need to worry where on the head you're clamping as long as it's the same on both ends. A couple of thoughts about possible tests:
Necessary force applied to obtain even force applied at the top and bottom of the head. (require 2 load cells and you can also check what loads you generally need to close up a joint)
What torque you need to apply to achieve the above force and the torque for a pre designated force (say 500N).
The diameter of the handle and whether the handle flips down horizontally to help apply the necessary force to draw the faces parallel.
How much the bar deflects when the faces are parallel and when say 500N of force is being generated.
Longevity, whether head starts to slip after 100,1000 clamp and releases (sorry this is going to be very boring)
Whether the bars rust when PVA glue is left on them for a couple of days.
Whether the clamps still work or are damaged when dropped 10 times from a bench height.
Clamp face width and depth.
Obviously some of the tests would require some explaining why they're not valid in certain circumstances. Hopefully that's vaguely helpful :)
I really appreciated your point of view on this subject, well done
As a beginner, this makes me glad I started with pipe clamps. Good to know not to crank any clamp down too hard. Thanks!
A well-prepared piece of wood for a panel needs very little pressure. When I did production work, I used I-Bar clamps (I had over two hundred.) I now use nothing but Rockler aluminum bar clamps. Don't have the grip in my hands for parallel clamps.
Great video.
Is it the case that perhaps pipe clamps are a better choice for panel glue ups? There isn’t the same downward force on the ends as with bar clamps but there should be zero deflection in the middle. Alternating (up and downward facing) pipe clamps should negate the need for downward force. Thoughts?
Fantastic insight! I think a lot of folks gravitate towards parallel clamps because they are the precieved "premium" clamp. A well equipped shop really should have a variety of clamp types. I don't understand why the venerable pipe clamp doesn't get more credit.
7:00 Glad to know that my cheaping out and only having pipe clamps is the best choice
My mistake has always been using parallel clamps for cabinet carcass glue ups. What Mark shows at 2:22 tends to deform the side of my cabinet before it puts pressure on the joint.
I noticed that a few years back if you use them sideways it doesn’t affect the panels that way
@@spycedezynuk i second this, and is actually what Bessey reccomends. Use the side of the clamp / turn it 90 degrees. I suppose this also works for thin panels.
Great info, Marc~! I didn't know this detail about parallel clamps. Thanks for the education (as always)~!!
I use parallel clamps for my panel glue-ups but I lay them down on their side so that the toe gets smushed straight.
Thanks for the honest enlightening results. The more panel clamping videos I see, the more I think that 4 direction panel clamps are superior though underutilized.
as a retired furniture maker i obviously never had parallel clamps back in the day. i have looked at them and thought they look good until i saw the price lol. i spent my working life using the old bar clamps which had very little deflection unless you over tightened them. when applying clamps you need to do the old over under to keep the panel nice and level and increase the pressure slowly with a bit on each clamp before applying yet more pressure. and you are right, most people over clamp their work.
You touched on it briefly, but the most important part of this video - don’t go into debt over freaking clamps.
Solid video, well laid out and articulated as always.
I watched a bad parallel clamp review, and im glad you made a great parallel clamp review. What are your thoughts on pipe clamps?
Good review of reviews. In order to review something you first have to understand what it is supposed to do. Keep up the good work.