Glue surface prep: Less important than I thought
ฝัง
- เผยแพร่เมื่อ 1 ธ.ค. 2024
- Testing how well the glue sticks to wood that's been lying around for a while vs. freshly sanded or planed down a bit.
I expected this to make much more difference than it did, even with some non-ideal surfaces.
Lots more glue testing related work at the bottom of this page:
woodgears.ca/j...
Questions about different gluing parameters keep coming up. I have done a number of videos on this sort of thing, all linked from the bottom of this article: woodgears.ca/joint_strength/index.html
In the UK most people use Evostik wood adhesive, which claims to be "stronger than th wood itself" and to be fair, I have never had a joint fail with it. It's pricey but good.
Thank you for highlighting the science publication connection. The search for positive (interesting) results is strong and leaves opportunities unused, and works against young scientists that try to do science for the sake of gaining insights, not publications
I know you probably not a fan but you could try to market the video as something among the lines of Preping is a waste of time, or You are doing it wrong, idk. I find it interesting regardless but im not the average viewer
I would love to see a follow up to this on how much the surface area matters. Like does it follow a linear or square cubed relationship? Especially interesting was the gap filled with glue being stronger.
I guess another interesting idea would be to use your jig to do a racking test - flexing about 50% of a joint strength how many cycles before it fails
@@mickeyfilmer5551 about being stronger then wood, just like any other wood glue out there... except they are not pricey.
Negative results are quite important, the problem is that they are not as satisfying as positive ones, glad you decide to post it is quite interesting to know
Well, the other alternative was to not publish at all. Even a video that does do well is worth publishing if I already filmed it!
@@matthiaswandel --- Alternatively (again), published negative results can often help focus the research in your field to approach a problem using another methodology. Saving them from wasting time and resources on a similar direction. That's not to say every crappy result should be published and clearly some thought has to be put into the usefulness of the work to community. So in a sense, you both have a point!
For a person who needs glue joints to hold up, and for whom time is a limiting factor, I think this video s both interesting and has satisfying results. I'll spend more time on surface contact and mechanical strength than surface prep behind making sure it's clean and smooth.
This is great. It makes me feel a lot better beeing lazy when gluing stuff. Wood glue really seems to match the properties of the wood, even when filling gaps and attaching to weathered surfaces.
@@matthiaswandel I don't quite follow. Weather the video does well or not is clear only after you publish it. And in this upside down world, publishing a disenchanting "negative" outcome can easily be viewed as "news worth telling". You invested some days and for whatever that's worth, the time and samples investigated are a statement.
A test set that refutes common understanding is arguably more interesting than one that supports it.
Agree, *objectively ‘refutes’. And even better, concludes less prep is needed for equally good results… a bonus 😀
Mattias, your honesty and openness about the facts of the matter are refreshing compared to so many of the others on this platform, where just a little innocent deceit will translate into more YT dollars. You have gained a world of trust from a lot of people.
Man I love this. Keep it coming man. Thanks for all your work.
Many others have stated similarly already, but i will add my own 2 cents: Thank you for being honest. It may not help monetarily in this case, but I think this video will help indirectly, by continuing to build our trust in you and your content. I have been subscribed for nearly a decade, and one thing I've always noticed was your integrity. That's not something money can buy. It's built. It's one of the reasons why I've bought some of your plans. It's because I trust your plans and your machines.
Thank you for being my trusted teacher for woodworking over the years. Your time and research have been invaluable to me, and my family.
Thats the kind of video that reminds me why Ive been watching you for 10 years. Thanks again Matthias.
I learned that surface preparation makes a big difference when curb-picking plywood. I acquired some thin plywood that I used for a project. The wood had some varnish on it, but the thin, satin finish and dull patina didn't make it apparent that the varnish was there. Did a big glue-up, and the whole thing fell apart when I went to mount it in place!
I didn't mention varnish, yeah, that makes a huge difference!
@@matthiaswandel It goes to the uncertainty aspect. We aren't making it worse by prepping the surface but we might be wasting our time. Given that most of us make so few things like this we happily waste our time and sleep better at night! But damn the over the shoulder guys tsking and saying we must!
I'm impressed with how well those sole glue joints were able to hold on.
PVA glue is a wonderful thing. A lot is holding together today that really shouldn't.
What I would take from your observations is that there are additional uncontrolled variables that are substantially affecting the outcome as much or more than surface preparation.
Yes, probably mostly a matter of how easily the wood tears out
@@matthiaswandel if the wood fibres are exiting the face of the board diagonally in one direction and you rotate the board, then surely in one direction they are being peeled out of the face and in the other direction they are sort of levered in.
E.G. here’s a cross section of the joint in ascii
|\\|=
|//|=
If you push upwards on the end of the equals sign, would you say the first example may be more likely to split the face grain of the board than the second?
Do you think the rotation of the face board would explain some of the difference in the pairs of planed surface tests? And therefore could affect the other tests?
As always, this is the empirical testing that long term subscribers thrive on. The proof of minimal (or even no) gain from faffy tasks is sure to speed up some processes. Keep on keeping on 👍
While that's not groundbraking science, I still very much appreciate this small experiment! Thanks for sharing 😊
Of course not. It's woodbreaking science!
Sorry I had to. I'm behind on my quota.
@akaHarvesteR Don't you dare apologize for that 😉
Not a woodworker by any means but your insight on scientific research is a refeshing perspective and much appreciated. Thanks and happy thanksgiving.
THANK YOU Matthias, Its great to see you post an example of science at work, and how often our 'beliefs' can often be wrong when you actually tried to confirm it. I love science and failures, since that often helps us develop different beliefs and additional tests to confirm those new beliefs. Good Job.
I would have to say the sample size was too small. Since wood density and grain structure varies so much in wood (even on the same piece) it’s going to need many more samples to convince me that glue holds better using either method. Then you have so many different types of wood that it could show opposite results because some wood takes glue better than other types of wood, and I’m only talking domestic wood, not exotic woods. What a nightmare. I’m already sweating and I’m not doing the work.
Really interesting ! Reminds me of a tale I read 35 years ago in a book by JE Gordon (can’t remember which - possibly The New Science of Strong Materials: Or Why You Don't Fall Through the Floor and Structures - and excellent book) in which he says that during the Second World War they had problems with Spitfire planes - where wood laminations were critically failing on planes due to improperly prepared joints - so their solution was to shot blast the wood in the factory as it was a process that couldn’t be screwed up by laziness on the production line… and resulted in excellent glue joins !
Amazing connection about that book. It is great that you mentioned that. I was thinking about that same section in that book as I was watching this video. Glad someone else is familiar with it. That’s a great book. I gave it away years ago. I need to get another copy.
Mattias, I think grain runout on the face grain surface is what's causing your results to appear random. I mention this because in the short test pieces you used, you flipped each one 180 degrees to pop the eng-grain glued surface loose from the face grain. When the grain runout was facing downward, the glue joint lifted fibers from the wood.
That's interesting. I also wonder about end grain butt joint. I'm not sure if the results would be different if the glue surfaces were long grain to long grain, but I do think they might be... Maybe the preparation does matter then.
Thank you for doing the science Mr. Wandel. Really helpful
Thanks for doing the testing that I don't have resources to do. My usual use of re-purposed wood for projects will continue. I always try to at least have a clean surface for gluing. If I have a structural item, I make sure to not rely solely on the glue (add screws, dowels, etc.). Knowing that the testing is already done gives me more confidence in the projects I do.
Veritasium's "Most...wrong" may be the best video ever about critical thinking. Why you should evaluate information for yourself. Nice video about sanding and gluing too, thank you.
I wonder if scratching the wood real good with very coarse sandpaper or a knife like the cuts they do on pressure treated lumber can actually increase the grip of glue
Interesting because your test methods are thorough, most of variability removed, and trustworthy regardless of the actual subject.
An interesting side note. FAA handbook for airplane building and repair recommends that glue joints on wood structures be planed and not sanded. Looks like that might not make that much difference, although testing on spruce might be a good idea since that seems to be the wood of choice for wood airplanes.
I have seen at least one research paper showing that planed wood gave higher bond strength than sanded - the theory was that the undamaged fibres of the planed material were stronger. So this supports your FAA citation.
The theory is that the grain straws have open ends when planed, similar in shape to a syringe needle and that would provide more ancor depth for the glue, but as Matthias showed, it’s not making much difference.
@@amconsole Mattias did not do the one thing you're supposed to do when gluing up which is to apply pressure during the drying window. Glues behave very differently when properly pressurized versus lightly applied. So at best, I'd say this result shows your surface prep doesn't matter much if you're not properly clamping the joint, but I wouldn't assume the same holds for properly clamped joints.
Interesting experiment. I also did something that came out contrary to expectation. I made 5 or 6 wooden hold-fasts generally following TH-camr's instructions. I hate spending money, so I used runny epoxy that was made for tabletops instead of wood glue. And I used salvaged dowels that I think were pine or poplar instead of hardwood dowels. And I used what I thought was old, hardened pine for the clamp piece that attaches to the dowel. I was careful to get and 83 degree angle between the dowel and the clamp piece. I expected them to break. But they all work perfectly.
Does the amount of sanding make a difference?
I've always been of the opinion that a roughly sanded piece (eg. 40 grit) will give a stronger joint than a finely sanded piece (eg. 240 grit). I assume the wood fibres will knit together more if it is coarsely sanded. No idea if I am correct or not
Just the fact that the prep doesn't matter is VERY interesting! But, I watch all your videos regardless. Even the ones that I really don't understand. I'm definitely drawn to your unique intelligence.
When all else has been ruled out, whatever is left, no matter how odd, must be the truth. thanks for another great video 😊
Actually, you have taught me one more thing I don’t have to worry about. Removing concerns is quite valuable.
Time between surface preperation and gluing, amount of glue (g/m^2), glueline thickness, pressing force while curing, moisture content of the wood, temperature (wood and glue), age of adhesive and most importantly type of glue have an impact too. Most adhesive manufactures provide detailed instructions for processing.
Used 48 hours for all, glue was enough to fill it. Pressing force was weight of the wood, mositure content all same as it was all wood in my shop for years. So all these were consistent.
@@matthiaswandel So basically you didn't apply pressure to a glue type that does require some pressure. Your load testing also seems to be coherent with the results of Workshop Companion with the pressure vs no pressure bond strength. My assumption is no pressure leads to no penetration.
Thank you for doing the experiment, and publishing the negative results! Super appreciated and valuable!
All testing is interesting, especially when the results aren't what you expected. Now we don't have to sand joints before gluing and if we sand for other reasons we know we're not losing anything because of that. 3 good things from one video!
For some context, joint sealant companies (polyurethane, silicone, etc) provide detailed instructions about CLEANING surfaces to improve adhesion, but very rarely have I seen mention of sanding. Wood in ANY milled condition will be more porous and able to hold glue than commonly sealed materials like metal, plastic, and paint, so it makes sense to me that wood doesn't need any more sanding. It just needs to be clean, so without old adhesives or paints or obvious oils. Great work as always!
Even a less spectacular result is a result. And not forcing your own research results in a particular direction was the right choice.
That is a really interesting and unexpected result, thanks!
Try to Apply pressure using a clamp. Hypotezis is that there could be an effect of hydrostatic pressure forcing the glue info the surfaces creating better grip for the glue Best Tor Erik From Norway
Since you have the machine built and a nice rhythm going, I'd also like to know about old vs new glue as well as glue that has gone through a couple a freeze/thaw cycles.
I've never prepped a surface before gluing or painting, glad to see that it didn't matter anyways.
Interesting stuff as always. Would love to see if it makes any more difference with edge or face grain as opposed to a butt joint. I learned some time ago that wood fibers raise and interlock while gluing a very well prepared joint. Not sure it happens with end grain.
Really interesting.Finding out that surface prep isn't too important is still an important result so don't be too hard on yourself Matthias.
I wonder how strong the joints would be with one or two screws of varying length(piloted vs unpiloted) instead of/as well as the glue.
You also found out that the quality of the wood/ply can be much more important.
A good follow-up experiment may be to repeat using face grain to face grain with various contact areas and woods.
Ahh… science at work. I think we Americans could learn a lot by your examples. Keep up the good work.
The fact that it makes little to no difference is interesting in it's own right when you consider that most people would swear it does.
Not only positive results are worth recording.
I was pretty sure it makes more difference too.
When I used to put pewter miniatures together I would score the parts to be glued with cross hatched lines made with an x-acto knife, in order to give the surfaces more of a raised tooth for the CA glue to bond to. I always wondered how much value it had, and if it would do anything if it was applied to wood working, but I never saw anyone, anywhere doing it. Based on these results I think it would be safe to say that it would probably have similar results and possibly improve the bond but only slightly.
Clamped vs unclamped glue test would be interesting.
Yes please!
Also clamp time. Do the clamps really need to stay on for hours or is it ok to remove them after 10 minutes to half an hour?
Tested that more than a decade ago.
@@matthiaswandel I thought so but couldn't find the video.
@@Ultrazaubererger I think the one he's referring to is named "Can you squeeze all the glue out of a joint?"
I've been a carpenter/joiner for over 40 years and to be honest, I have found that a lot of what we are told is nothing more than manufacturer/retailer/influencer/publication propaganda and should not be taken too seriously. Obviously this is not the case in all circumstances because some things are fact and they will mainly be down to common sense. The rest is little more than myth and fairy tales. For instance, centuries of fine furniture was created using hand planes that were sharpened nowhere near what is now recommended - 1,200 grit and even way more. 240 grit is ample because at the end, the piece is sanded back down to 240 grit for applying a finish. The companies recommending the 'must have' requirements are doing it for one thing - your money...!
If this video highlights one thing, it is that end grain butt joints do not adhere well, regardless of what they are being glued to. I dare say that epoxy would fare better, to some extent.
Yes, a lot of these recommendations, I would take them more seriously if they also told you what happens if you don't follow the recommendations!
Capitalism in a nut shelle
@@augustolsson9248 No.
@@augustolsson9248 Commie, much?
As always, thanks for the raw, basic science. Interesting result or not, now we have some data!
But these results ARE interesting. Because it told us the opposite of what we expected. Actually I would argue that makes it even more interesting than the other/expected outcome
I love those tests!
Could you put them all in a playlist so they are easier to find?
woodgears.ca/joint_strength -- see links at bottom of page.
Very nice framing with the number between the pieces!
Curious if clamping the wood down for a more traditional joint would make a difference
As you always glue both surfaces (not here but in other videos where you glue tenants and joints) it would be a great test for you to see if that makes a difference. In my opinion (I am not a woodworker) using glue only on one surface should be enough.
It depends, if you put glue on and then clamp hard straight away, the glue gets squeezed out before the other surface has a chance to soak up anything. It will however soak stuff up, resulting in a glue starved joint. So if its just glue on one surface, don't clamp hard straight away. Though I think 15 seconds between joining and clamping pressure is sufficient.
Thank you for this. I'd like to see ne more test, clamping vs not. You're already pulling out fibres; would you get them from deeper if clamped?
Makes me wonder how much it comes down to exact grain orientation at the microscopic level since it's virtually impossible all fibers are running exactly parallel to the surface. Sanding wouldn't do much of anything except help expose a few slightly deeper fibers, and for every severed fiber end, a weak point is produced leaving you dependant on the adhesion between fibers rather than the tensile strength of the fibers themselves.
I notice that your test inverted the base plywood between the first and second joints. If the surface ply on the plywood has distinct grain orientation, then one orientation may be stronger.
This IS a surprising result!!
Our spec in the aircraft industry, after sanding all faying surfaces, remove dust with compressed air and saturate lint free rag with 50/50 isopropyl alcohol/water then wipe surface and let flash off for 5 minutes before gluing.
Sometimes compressed air has a lot of oil in it. I guess you guys were using clean compressed air. Anyway, for the home DIY person, it might be safer to use a vacuum to remove dust, unless they have filters on their compressed air. The alcohol wipe will help also.
Did you clamp the pieces together as the glue cured? Sort of a bigger “meh” if you didn’t. Always enjoy your intellect and videos!
Didn't clamp. So long as there is enough glue in the joint, clamping doesn't help
@@matthiaswandel Uh oh, sounds like you need a clamping vs. non-clamping video now 😅
I'd be interested in the same test, but one with pressure while the glue goes off and one without.
I wonder if you have two factors -- the patina vs dustiness caused by sanding. If you used a tack cloth and / or isopropyl alcohol to prep the surfaces to remove dust and oil, I bet you'd also have some interesting results.
Such a great video.
Idea: wetting fresh wood and letting it dry naturally raises the grain (which is a nice trick i use before final sanding, for a really smooth finish on knife handles and such)
What if you wet the wood and let it dry, before gluing? Would that make a difference?
I had the same thought. Opening the grain to encourage greater glue penetration, without sanding. The real question is whether Matthias has the time/interest/energy.
pva glue is majority water and what happens before the glue can set is all the moisture has to be soaked away from the polymer by the woods capillary action.
@matthiaswandel, love your videos. Thank you. Have you considered doing one with dry time? Maybe one with 30 mins, 6 hours, and 24 hours or something like that. I have always been curious to know how much time is actually is needed to make a strong joint. Thanks!
What about under clamping force? As I understand it, the clamping force helps to force the glue into the wood fibers. With clamping, the glue may get deeper into the sanded wood, causing more wood failures on that side. On the unsanded side, at least in cases where there's old finish or shmoo, that water-impermeable barrier will prevent the glue from soaking in, resulting in glue failures.
Great tests Matthias! Wouldn't clamping make a difference here to add pressure and further strengthen the joint? Perhaps the difference in surface prep is more visible after clamping?
Thanks for this, great data. If i could make a suggestion. I use a pre soak on the end cuts, i apply glue to the end cut, let it soak in for about 1/2 the open time, then reapply glue as normal on both surfaces. Also I like end grains with just saw cut no sanding. I am very curious to see those results, if it makes no difference that would be a time saver for me.
I really despise wanting to have results that are interesting.
Even though your results do not fit your hypothesis, it's still a GOOD research! We now know surface prep does not affect glue strength that much, I'll say that's still interesting and good research!
Nice. Less work to be done, that's always appreciated.
It's interesting to me. Love the video.
I fail to see how this is a failure, it produced results, it told you some important things and future ideas to expand your experiment. How rough sawn does the timber have to be before sanding becomes useful.
Hi Matthias!! Huge fan of yours here in Australia. Would you be able to do a video about gap filler? Like resistance to flex, vibration, etc? Thank you for sharing all your experiments - you were my mentor when I started woodworking a few years ago 😊
Actually, it’s good to know that surface prep for appearance does not significantly impact adhesion. With the examples of high number sanding resulting in packed pores (Fine Woodworking), I wonder if sanding beyond 180 or 220 does adversely affect adhesion.
Thank you for this video! My assumptions about preparation was finally proven. :)
I wonder if scoring the surface as opposed to sanding would help. my thought being that in the scored areas there would be exposed end grains which should allow the glue to better absorb into the side grained wood.
Hi Matthias! I have heard that the strength of a mortise and tenon joint is determined by a few thousands of an inch in fitment. What do you think is the optimal "snugness" for this joint, and what should be considered "too loose"? Is the old adage that a dry-fit joint should be able support its own weight correct?
Also, some woodworkers go through a lot of trouble to refine mortise walls and tenon cheeks as much as possible, essentially producing surfaces similar to being hand planed. Is this even necessary? How much different is a mortise right off of the router or hollow chisel mortiser, and a tenon right off of the table saw with no further surface prep? Could the rougher surfaces even be stronger given that they have the potential to hold more glue?
Suggestions for testing how big a difference there is when gluing with and without weight on glue joints in press?
This video makes a good point about glue surface prep. I wonder if the conclusions would be the same without using end grain? It would obviously be a stronger joint, but by how much?
Idea for next experiment: how much clamping force improve strength? Maybe here glue layer thickness was not uniform.
Love your glue and joint test videos. Definitely interesting results. Could you possibly do a testing of glue application? Specifically using glue on both sides of a joint instead of one. And a end grain to end grain regular glue up vs putting glue on the end grain, letting soak an applying more to account for the soak.up.
In practice, it seldom matters to me and I don'tgive it much thought. I usually only use glue for sanded projects, and then I like to do most of the surface prep first anyway. And even if that's not the case, I only use glue to keep a mechanical joint together. Maybe sometimes side grain to side grain, but then the surafce are is typically relatively large anyway .But they are always fun experiments to follow and to understand better what method to use when.
Newbie question!
I made 4 table legs which are a bit odd but have large flat surfaces. How do I sand the leg tops so that the tops are perpendicular to these flat surfaces? I just have an orbital sander and a belt sander but have no idea of how to do perpendicular sanding with these tools without just eyeballing it. Is there a way to do it better? Thanks!
I wonder how a scratched up joint surface would compare to all these smooth (sanded and plained) surfaces that you tested here. Thanks for the video!
I think a video on how different clamping forces affect joint strength would be a good video
woodgears.ca/joint_strength/index.html
I'd love to see this expanded to include some of the finished surfaces found on reclaimed wood you so frequently use.
Anything with a polymer coating will more or less fall apart as the glue can't soak in
@@AnnaVannieuwenhuyse Sure, that's my gut reaction as well.
But I think the very concept that 'soaking in' as a requirement for wood glue to function adequately is the assumption that would be interesting to challenge and confirm empirically.
I’m sure that gluing the end grain is the problem. If you tested glue joints grain to grain the results would be hugely different. Thanks for the videos Matthias.
Can I ask about the grain orientation of the base in relation to the orientation of the grain in the test blocks? The direction of force on all of them seemed to be in the direction of the grain. Unless I am wrong? If the grain orientation was 180 degrees from the blocks, might the glue bond be stronger?
Since the joints were being assembled end-to-face grain, there might have been more glue available to wick into the end grain with the older surface.
Was the gluing done under clamping pressure?
I guess the ultimate limit is the strength of the fibers just below the surface, and both types of joint got close enough to that so there wasn't much room to make a difference.
I guess a more variable test might be looking for how badly different contaminants can poison a joint; dirt, dust, varnish, or stain, wet wood vs. dry etc.
I am glad to know that l can omit some degree of surface prep if I'm working with wood that's already in decent condition and I'm in a hurry or just don't wanna make more of a mess than necessary
@matthiaswandel, I love what you're doing here. Try freshly finished/coated pieces against bare wood, and freshly finished and re-sanded wood. I believe that is where you will see your "ahaaa" moment.
And that is a very interesting result.
I’ve heard that if you expose the glue to the air for 5 minutes before connecting the two pieces, the bond will be stronger. Should test that!
I wonder if a hide glue would be any different? From Wood by Wright's testing yellow glue was a pretty good gap filler (if o remember right..)
What if there is tiny little bump and the sanding is not there to do anything with the old surface but to get rid of that one random bump that could or could not be there?
Great work
Mattias, I am sure you are aware that most research is biased towards positive results. So, thank you for posting your observations!
And, as someone else pointed out, most recommendations for processes are not based on randomized trials with adequate sample size and proper analysis of the data. Though I am sure there are some areas where there is scientific data available.
I wonder if there's an element of probability at play here, and if the sample size was dramatically increased, do you think the results would be more clear-cut?
For me the conclusion of this video is maybe more interesting than one being better than the other.
After years of hearing end grain is a weak glue joint it is interesting zero failures were caused by it!
Yeah. A youtuber, maybe Matthias, did a video on that. As I remember, the end grain glue joint was actually stronger than a side grain glue joint because the glue wicks into the end grain. The reason why the saying exists is because the end grain joint is weaker than the wood (in that direction) while the side grain glue joint is stronger than the wood. If you take two 1 foot pieces of 1x4 and join them end to end the glue joint breaks at a much lower point than a 2 foot piece of wood because wood in that direction is extremely strong. If you glue them side by side the wood breaks before the glue (because wood is weak cross grain) so it is just as strong (possibly even stronger with proper grain selection) than an equivalent 1x8. The saying should be that an end grain glue joint is weak in comparison to joinery. So for example in the case of the butt joints in this video a mortise and tenon (or dowels, domino, etc) is much stronger. In the example of two boards end to end a scarf joint or dowels is stronger.
End grain glue is MUCH stronger, but also much weaker than the wood. Also, end grain to side grain will fail over the years due to moisture changes shrhinking and expanding one part much more than the other.
Would clamping, pushing the glue into the fibres, change anything?
Well, I'm actually getting a compelling message from these results:
"DON'T SWEAT IT." Make your joints, do good work, design in some overhead for edge cases. But a lot of stuff that you've thought might be minutiae? Yeah. It's minutiae. Don't sweat it.
I wonder how much temperature would affect it , maybe try heating the surface to open pores to allow for deeper glue penetration…. Either love all you videos and knowledge
I wonder if grain orientation makes a difference in glue vs wood failure?
Great stuff Matthias. Its all about penetration. It may have been worth wetting some of the joints prior to gluing.
I think you would also have to dry it after the wetting. Unless you're using polyurethane glue, but that's an entirely different matter 🙂
@@briantaylor9266 Maybe partially, but it would allow capillary action for better penetration. :)
Thanks. Some processes may be holdovers when they still used stuff like bone glue that needed every help it could get to work.
I wonder what a swipe with a wet sponge would do if anything, can old wood get so dry that it acts like it’s a little hydrophobic, not drawing any glue into the pores? Just a thought.