This is a very good explanation and really great advice. When I was doing collision repair, it was standard practice to apply filler directly to bare metal to save both time and money. However, every time a repair would get into an area that had filler applied from a previous repair I would always find some type of corrosion between the filler and metal and the filler could often be popped off. As a result of this, once I opened my own shop doing restoration work, I started spraying epoxy after doing metal work but before applying filler. The cost of two coats of epoxy is nothing compared to the cost of your reputation when you have to warranty a repair for bubbling/blistering.
Explaining it perfectly. I've been in the body shop biz 32+years and been around it over 35 years. Everyone out there was taught to plastic over bare metal. Guys that have been doing this type of work from way back when, cannot grasp the idea of not putting plastic work directly over bare metal. Hard to teach an old dog new tricks. This channel if great. Keep it coming. Is nice to see a real professional approach to this type of work.
I understand what's being explained here but there are so many variables in body and paint and different techniques. Like what condition that bare metal on that Dodge was in before the body work was even started. We don't know. The filler could have been applied over sanded rust like some amateurs do. So was it really the filler reaction or poor prep? Like people online bashing polyester primer adhesion not realizing years ago it was only designed for small areas of bare metal not whole bare panels. I did a collision repair on my own car with filler over metal. Daily driver in road salt put over 200k and the filler never popped. Point is, the epoxy is a fail safe but there are a lot of different situations out there that no one will ever know what was done. Some of these restorations were done years ago before better products and techniques.
Agreed... years ago repair shops used filler over bare metal all the time.....I've removed 40 year old repairs over bare metal and even over un- catalyzed paint that was still in good condition ...
I agree, my dad was a body guy in the '60's and 70's and I saw cars he'd painted that were 20 years old and no issues. These guys do great work but I don't think they are always correct. You can over analyze things and I believe that they do. I do things the way my dad taught me and they last then I watch stuff like this and they tell me that what I know and have witnessed is all wrong! 🤔 Sorry boy's I'm just not buying it!
Have a couple of cars I did almost 50 years ago a Cadillac and a Lincoln still look perfect and we're done with filler over metal and all Sherwin-Williams lacquer products including ultra fill lacquer primer , Sherwin-Williams sealer Sherwin-Williams Acrylic Black Lacquer still looking perfect no cracks blistering or shrinkage ! I did use claussen company ZChrome Body Filler which state is rust inhibitor also used their non shrinking Nitro red glazing putty which they don't make any longer use UPol now
Im glad I stumble on this video Im not auto painter but I do everything in my cars, but rust is my problem and repeated every year and and countless video tutorial to make my rust repair last.. Thank you
I am sure its a great thing to do ...and this technician has been taught this from the begining ....but 20 years ago when i worked in an auto body repair shop ....it was very common to put filler on bare metal ....and then y2k urathane primer over the repair ....usually several coats so it could be blocked to profection ....then after all the pre prep before paint ....would use a color specific tinted sealer to lock it all down ....all body work comes down to prep ....better the surface is prepped better results you will achieve....i did a 94 s10 frame off and did several areas of bare metal filler ....and it still looks amazing to this day ....i dont own it anymore but paint and body work still looks amazing on the truck.....but i am sure the epoxy has its benifits .....but you can use filler on bare metal
I bet that 94 s10 was fun. You can't get the transmission separated from the engine without pulling the cab, and you can't get the engine mounts off without stripping the front half of the truck to get to the non captive nuts in the frame
So many shops go to bare metal and start body work. I'm a newb and know better . Why take a chance? Again this channel continues to give quality videos. Ty!
I entirely agree with you on this and use filler over epoxy these days. But... back in the day I did use it straight over clean prepped metal and I've still got a car I restored in '89 (35 years ago!) that still hasn't suffered filler failure anywhere to date, so the old school method doesn't always fail!
Great explanation, WAY back in “the day” we did collision repair we would use fiberglass “kitty hair” over bare metal when we would have done a metal patch repair, then primer and finish with body filler as needed
Thanks for this. I was under the same impression. Glad someone said it tho. I mean me personally have a steel bumper that rusted from the inside and started to bubble on the outside through the paint. The metal has to be compromised since its all bublly even after taking a grinder and wire wheel to it. So epoxy on the inside and outside before body filler just makes sense.
I always thought what a bs idea to put something else than rust inhibiter on pure metal? I use, cause epoxy stuff is very expensive in brasil, a paint or primer that´s made to go over rust. I clean and treat chemical before, but I use this direct on rust stuff, then i go with filler. I´m not a pro, but I did on my first job what "everybody" told to do, and it went wrong. today I go my way and it works better,
I agree with this guy, filler onto bare metal starts rusting because of the acid in product doesn’t matter how clean the surface is it starts the rusting process.
I never did body work before. I did some research and anytime I see body filler I always see rust under it. 5 years ago I strip my car to baremetal my first car paintjob. I used epoxy primer then body filler then epoxy prime on top of it. Then my paint job guess what after 5 years I have 0 rust anywhere thank you for explaining
You should be able to epoxy over filler and technically get the same results. Either way, you'll be sanding through the epoxy before you put filler over it. So technically, the epoxy will be compromised before you apply filler. As long as you don't leave the metal exposed for to long before you finish bondo and spray epoxy it should give you similar results. I've done both but I prefer directly to metal because the epoxy tends to be brittle and could have adhesion problems after sanding it with 80 to 120 grit. And either way I would epoxy over everything after the filler was finished sanded.
it's crazy i just watched D.I.Y Auto schools channel and his saying totally the opposite thing (maybe a bit old school in his way of thinking?) however I'm with you on this one epoxy is there to seal up metal then once sealed you work on top of that and to me that makes far more sense.. I'm even going epoxy, body filler, epoxy over the body filler and then final paint might be over kill but in the 40 series Landcruiser world most people seem to go this route
Some of the old filler would not stick to some metals as some primers. Youte living in the dark ages as far as epoxy is concerned Lowered new dtm primer filler like z grip that stick better than epoxy We don't use epoxy because it creates suction in clear coats scratches. It makes another hundred bucks for something that's only pushed by utube beginners that 5:01
My hat is off to you my friend. It's surprising how many so called "tech's" don't know this and don't care! It's just unfortunate that by the time this becomes standard practice the amount of vehicles made will barely have any metal in them😂😁
Kitty hair is a polyester product like all fillers. It’s no exception. Always epoxy first. Sense we’re hear, I’ll recommend Fibertech. It’s tough as nails and was our go-to for years before our switch to Epoxy filler. Kitty Hair should have been discontinued 40 years ago.
Is it safe to put my high build right over my epoxy? I’m locking down my filler and exposed metal from sanding with another coat of epoxy and would wait about 2 hrs and then stack 3 coats of high build. My tds sheet says I can do this but like to hear from some of the best. Just trying to save myself more sanding if possible. I’m just worried about possible solvent trap or do you think it should be ok. After high build is sprayed my cab will sit for a good month or so before I go back to blocking to make sure everything has shrunk and off gassed.
Does bondo Glass suck up water too like regular bondo or is it really waterproof like it advertises? Do you think it will rust also if you put it on bare metal?
Yes I preach this because of watching linear blocks vids, just makes good sense, but the old school guys will rip your head off because they have been doing it for years and it lasts forever 🙄.
If you’re not using a crud thug over your metal on the rust of course filler and epoxy will come off numb nuts. At the end of the day, metal has a way of being prepped period. If you don’t do it right in any area, your epoxy will peel as well.
Good explanation. Unfortunately it’s never going to happen in the collision world. Fortunately quality guys know better. We’ve had an epoxy based body filler in testing for years now. It’s actually an aircraft spec coating. It has phenomenal adhesion, zero shrinkage, very tough, and has give to it. And because it’s epoxy, it’s 100% acceptable to put directly to metal. It takes 8 hours to cure, but worth it completely.
Body filler on bare metal is a faster way and better way of working old schools because if your metal is not prepped correctly to 80 grit sand paper at minimum, epoxy can peel just like filler. Saying filler shouldn’t go on bare metal is B.S my guy.
This is a very good explanation and really great advice.
When I was doing collision repair, it was standard practice to apply filler directly to bare metal to save both time and money. However, every time a repair would get into an area that had filler applied from a previous repair I would always find some type of corrosion between the filler and metal and the filler could often be popped off.
As a result of this, once I opened my own shop doing restoration work, I started spraying epoxy after doing metal work but before applying filler. The cost of two coats of epoxy is nothing compared to the cost of your reputation when you have to warranty a repair for bubbling/blistering.
Explaining it perfectly. I've been in the body shop biz 32+years and been around it over 35 years. Everyone out there was taught to plastic over bare metal. Guys that have been doing this type of work from way back when, cannot grasp the idea of not putting plastic work directly over bare metal. Hard to teach an old dog new tricks. This channel if great. Keep it coming. Is nice to see a real professional approach to this type of work.
I understand what's being explained here but there are so many variables in body and paint and different techniques. Like what condition that bare metal on that Dodge was in before the body work was even started. We don't know. The filler could have been applied over sanded rust like some amateurs do. So was it really the filler reaction or poor prep? Like people online bashing polyester primer adhesion not realizing years ago it was only designed for small areas of bare metal not whole bare panels. I did a collision repair on my own car with filler over metal. Daily driver in road salt put over 200k and the filler never popped. Point is, the epoxy is a fail safe but there are a lot of different situations out there that no one will ever know what was done. Some of these restorations were done years ago before better products and techniques.
Agreed... years ago repair shops used filler over bare metal all the time.....I've removed 40 year old repairs over bare metal and even over un- catalyzed paint that was still in good condition ...
I agree, my dad was a body guy in the '60's and 70's and I saw cars he'd painted that were 20 years old and no issues. These guys do great work but I don't think they are always correct. You can over analyze things and I believe that they do. I do things the way my dad taught me and they last then I watch stuff like this and they tell me that what I know and have witnessed is all wrong! 🤔 Sorry boy's I'm just not buying it!
Have a couple of cars I did almost 50 years ago a Cadillac and a Lincoln still look perfect and we're done with filler over metal and all Sherwin-Williams lacquer products including ultra fill lacquer primer , Sherwin-Williams sealer Sherwin-Williams Acrylic Black Lacquer still looking perfect no cracks blistering or shrinkage ! I did use claussen company ZChrome Body Filler which state is rust inhibitor also used their non shrinking Nitro red glazing putty which they don't make any longer use UPol now
Im glad I stumble on this video Im not auto painter but I do everything in my cars, but rust is my problem and repeated every year and and countless video tutorial to make my rust repair last.. Thank you
I am sure its a great thing to do ...and this technician has been taught this from the begining ....but 20 years ago when i worked in an auto body repair shop ....it was very common to put filler on bare metal ....and then y2k urathane primer over the repair ....usually several coats so it could be blocked to profection ....then after all the pre prep before paint ....would use a color specific tinted sealer to lock it all down ....all body work comes down to prep ....better the surface is prepped better results you will achieve....i did a 94 s10 frame off and did several areas of bare metal filler ....and it still looks amazing to this day ....i dont own it anymore but paint and body work still looks amazing on the truck.....but i am sure the epoxy has its benifits .....but you can use filler on bare metal
I bet that 94 s10 was fun. You can't get the transmission separated from the engine without pulling the cab, and you can't get the engine mounts off without stripping the front half of the truck to get to the non captive nuts in the frame
So many shops go to bare metal and start body work. I'm a newb and know better . Why take a chance?
Again this channel continues to give quality videos. Ty!
I entirely agree with you on this and use filler over epoxy these days. But... back in the day I did use it straight over clean prepped metal and I've still got a car I restored in '89 (35 years ago!) that still hasn't suffered filler failure anywhere to date, so the old school method doesn't always fail!
Do you sand or prep the epoxy before filler?
Great explanation, WAY back in “the day” we did collision repair we would use fiberglass “kitty hair” over bare metal when we would have done a metal patch repair, then primer and finish with body filler as needed
Thanks for this. I was under the same impression. Glad someone said it tho. I mean me personally have a steel bumper that rusted from the inside and started to bubble on the outside through the paint. The metal has to be compromised since its all bublly even after taking a grinder and wire wheel to it. So epoxy on the inside and outside before body filler just makes sense.
100% convinced now. I have never tried filler over bare metal before, and will definitely NOT try it in the future! Great video!
I always thought what a bs idea to put something else than rust inhibiter on pure metal? I use, cause epoxy stuff is very expensive in brasil, a paint or primer that´s made to go over rust. I clean and treat chemical before, but I use this direct on rust stuff, then i go with filler. I´m not a pro, but I did on my first job what "everybody" told to do, and it went wrong. today I go my way and it works better,
I agree with this guy, filler onto bare metal starts rusting because of the acid in product doesn’t matter how clean the surface is it starts the rusting process.
great video very well explained..
I never did body work before. I did some research and anytime I see body filler I always see rust under it. 5 years ago I strip my car to baremetal my first car paintjob. I used epoxy primer then body filler then epoxy prime on top of it. Then my paint job guess what after 5 years I have 0 rust anywhere thank you for explaining
You should be able to epoxy over filler and technically get the same results.
Either way, you'll be sanding through the epoxy before you put filler over it. So technically, the epoxy will be compromised before you apply filler.
As long as you don't leave the metal exposed for to long before you finish bondo and spray epoxy it should give you similar results.
I've done both but I prefer directly to metal because the epoxy tends to be brittle and could have adhesion problems after sanding it with 80 to 120 grit. And either way I would epoxy over everything after the filler was finished sanded.
I have seen rust under filler many times when stripping down to bare metal and it will eventually cause it to flake or break off
What about filler overtop fiberglass corvette .thanks
it's crazy i just watched D.I.Y Auto schools channel and his saying totally the opposite thing (maybe a bit old school in his way of thinking?) however I'm with you on this one epoxy is there to seal up metal then once sealed you work on top of that and to me that makes far more sense.. I'm even going epoxy, body filler, epoxy over the body filler and then final paint might be over kill but in the 40 series Landcruiser world most people seem to go this route
Some of the old filler would not stick to some metals as some primers. Youte living in the dark ages as far as epoxy is concerned
Lowered new dtm primer filler like z grip that stick better than epoxy
We don't use epoxy because it creates suction in clear coats scratches. It makes another hundred bucks for something that's only pushed by utube beginners that
5:01
Thanks for this! I have an area that i put epoxy primer and need filler. So do you sand at all or scotch brite, before filler?
Great video! can you tell me what scale you use for weighing filler? ...the ones I am finding aren't very accurate.
I clean my metal with grease and wax cleaner than use an etching wipe to prepare my metal. Clean it again than filler.
So wonder why you dont use etching primer , first over bare metal , before Urathane primer
No need for etching primer when you use epoxy. Epoxy is actually a step up.
My hat is off to you my friend. It's surprising how many so called "tech's" don't know this and don't care! It's just unfortunate that by the time this becomes standard practice the amount of vehicles made will barely have any metal in them😂😁
all filler except kitty hair right? Need to apply kitty hair over sail panel welds and tds said just metal. What is your procedure?
Kitty hair is a polyester product like all fillers. It’s no exception. Always epoxy first. Sense we’re hear, I’ll recommend Fibertech. It’s tough as nails and was our go-to for years before our switch to Epoxy filler. Kitty Hair should have been discontinued 40 years ago.
what is the brand of your measuring scale?
Thanks for info
Is it safe to put my high build right over my epoxy? I’m locking down my filler and exposed metal from sanding with another coat of epoxy and would wait about 2 hrs and then stack 3 coats of high build. My tds sheet says I can do this but like to hear from some of the best. Just trying to save myself more sanding if possible. I’m just worried about possible solvent trap or do you think it should be ok. After high build is sprayed my cab will sit for a good month or so before I go back to blocking to make sure everything has shrunk and off gassed.
Do you put another layer of epoxy or sealer again after filler or can you go straight to top coat?
Fiber Glass? does it work?
Does bondo Glass suck up water too like regular bondo or is it really waterproof like it advertises? Do you think it will rust also if you put it on bare metal?
Good videos!
Spot on well said
Yes I preach this because of watching linear blocks vids, just makes good sense, but the old school guys will rip your head off because they have been doing it for years and it lasts forever 🙄.
Lol..... So true
You see it all the time at car shows ….. totally agree with epoxy. Epoxy epoxy epoxy
If you’re not using a crud thug over your metal on the rust of course filler and epoxy will come off numb nuts. At the end of the day, metal has a way of being prepped period. If you don’t do it right in any area, your epoxy will peel as well.
Okay Ace. Why don't you put up a link for All your awesome restoration videos. Nothing like showing the world. You're a dick, right?
I sanded down,bondo,etching primer,epoxy,2k and i found rust. I 💯 agree with you, its all about treatment and prep.
I agree with some of his points. But certainly not all of them.
100% agree.
Epoxy is a link between the metal and polyester
BINGO !!!
Put Mipa onto the bare metal, let that dry, fill over it. Mipa is a corrosion protectant & it's damn good. Mipa ain't breathable.
Mipa what?
Good explanation. Unfortunately it’s never going to happen in the collision world. Fortunately quality guys know better.
We’ve had an epoxy based body filler in testing for years now. It’s actually an aircraft spec coating. It has phenomenal adhesion, zero shrinkage, very tough, and has give to it. And because it’s epoxy, it’s 100% acceptable to put directly to metal. It takes 8 hours to cure, but worth it completely.
🤣🤣🤣🤣🤣
Body filler on bare metal is a faster way and better way of working old schools because if your metal is not prepped correctly to 80 grit sand paper at minimum, epoxy can peel just like filler. Saying filler shouldn’t go on bare metal is B.S my guy.
If u put filler over Metal and SEAL it with Epoxy, ITS SEALED
Also, previous repairer, might not have treated the metal, or had moisture in their airlines
It's sealed from the top down. In that case. I'd rather seal my work from the bottom up.