Another problem with my 41 chevy!!! We have been having very cold temps up here for the last month or so with temps going down to -5! never had this before. So with that said heres my story.I took my 41 out of the garage sunday to give demo ride. I went about 3 miles whick about 1 mwas on I95. when i got back to my garage i noticed that alot of the paint on the roof flaked off!!!! Not alittle either, its about 12" wide & 36" long!! Peeled off perfectly, black, red primer & then it left a red primer on the roof!, I remember reading one time about the Norm Wallace roadster & how the paint peeled off that when they took it home one nite from the Boston WOW in the 60's or 70's. I think it was frombeing a old laquare (?) paint of something like that. Anyone ever see of hear of such shit? JimV
I've heard of very thick paint cracking when going from a warm building into extreme cold. Never have experienced it. IMHO, from the size you've described, I'm guessing adhesion was lost for some reason, i.e. bad prep, improper flash off of undercoats, etc... Usually real thick mil thickness of materials also.
Paint de laminated. Probably something was not done correctly between coats when applied. What type of paint is it?
the only time I have seen this (other than improper paint prep) was when we covered a car with a black tarp. the sun baked it off (in the winter) because of the tarp keeping moisture in & attracting the heat. old factory paint. might work if you wanted to strip it anyway.
When I was a kid in the early 60's I went to the Ray Farner custom car shows in the Minneapolis armory. They used to take 15 minutes to bring in some of the show cars from the outside temps of zero to the inside temps of 70, so all those coats of hand rubbed lacquer didn't pop off of the cars.
The paint job doesn't look new so its had to have been in alot of winters, but i think one problem might have been that i took it out of the garageso the for sale sign could be seen. So maybe expandtion & contraction from putting it back in the garage every night
I can't agree with the temperature causing paint to lift, otherwise the cars in the northern states wouldn't have any paint on them. The paint stopped before it hit bare metal which makes me think there has to be a problem with the prep.
My avatar is in the body shop now being stripped and repainted. Lacquer paint job probably from the 80s. Someone on the HAMB reflected that in the last 70s lacquer paint was reformulated to be "safer" which usually means "worse than nothing". Anyway I think our car was garage kept most of its life. But in our seasoned citizen life, we rent and the car was outside all summer. The paint started flaking off, especially on the roof but in this case right down to bare metal. Washing the car was like running your sponge over sandpaper.
Flaking off and coming off in sheets are usually and indication of different problems. Coming off in sheets is almost a guarantee that there was a problem with how the car was painted.
I would say that a problem with prep is the reason with near certainty. It cetainly is not related to temp changes and that leaves material issues or prep. Either way, it has to be removed completely and made certain that is is properly prepped and repainted with quality paint.
I knew of a guy that moved his custom from Hawaii to the mid west back in the '70s and the paint cracked the first winter he was here. he took it to a local paint shop and they told him it was from the drastic change in climate. I don't know how true that is but it is something that I remember hearing when I was younger.
I would think if the temp had anything to do with it, it would be a lot of cracks not comming off in sheets. must be the prep, how old is the paint?
Lacquer doesn't come off in sheets unless its near new and over a contaminated surface. Lacquer continues to harden and shrink over time to the point where it eventually cracks, and the cracking causes it to come off in small flakes or make the surface feel about like sandpaper. Enamels and urethanes retain enough flexibility over time to be capable of coming off in sheets if something causes them to release from the substrate. According to one auto paint manufacturer, a lot of the lifting problems with urethanes comes from spraying the color before the solvents have had enough time to evaporate from the primer. This is the main reason the car makers had so many lifting problems starting in the late 80's and continuing thru the 90's. The topcoat forms a skin that doesn't allow the solvents to pass thru. Normal heating cycles from sun exposure drives the solvent out of the primer but it can't pass thru the topcoat and evaporate, so it causes the topcoat to separate from the primer. Because its flexible, the topcoat doesn't necessarily come off at that time. It can sit there like a skin until the right conditions come about to allow the skin to break, and once that happens a sheet of whatever size is separated from the primer comes off. This can be clear separating from base, or single stage separating from primer. But, if the sheets come off to bare metal then its much more likely a prep problem rather than trapped solvents. For long term reliability of a urethane paint job that's going to be color sanded and buffed, the same manufacturer recommends sanding the finished topcoat after a couple days and then letting the car sit out in the sun for a while until the surface gets reasonably warm. Sanding breaks the impermeable skin on the paint, and the heat from the sun drives out any trapped solvents in the paint. I've tried this on some panels I've painted in learning to shoot base/clear paint. A panel that has no detectable smell at all can be sanded just enough to break the gloss, and then placed in the sun, and as it warms up it'll smell about like you just shot the paint half hour ago. Letting all these solvents escape before going forward with serious color sanding and buffing will reduce the likelihood of areas shrinking over time from the gradual escape of solvents, and showing up sand scratches and other defects, to near zero.
I was in the body and paint trade in the 70's here in Fairbanks Alaska, working for the GM dealer, then the Ford dealer. At the time our only paint dealer sold DuPont products. All spot and small repairs were done with Acrylic Lacquer and complete paint jobs were done with Alkyd Enamel. The only primer we ever used was lacquer primer and occasionally a sealer. There was never a problem with adhesion even with cars being taken to work from 70 degree garages, parked all day outdoors at -60 and returned to the 70 degree garage at night for weeks at a time. It was routine to paint a car, or a fender and pull it outside the next day after it was put back together. No problem. The only time I saw lacquer crack was on cars that had many layers from multiple repairs in the same area and it was very uncommon. We called it crazing and it looked sort of like shattered safety glass, only the pieces were larger. Even then they remained attached to the car. At the time DuPont Centari (acrylic enamel) was brand new and it had crazing issues in extreme cold weather that caused DuPont to pay for a lot of warranty repaint jobs. Even then, the paint did not come off, we had to remove it before we could repaint. They changed the formula after a couple years and solved the problem. If your paint has lost it's adhesion, my best guess is that it was not properly applied. Some backyard builder (not a derogatory reference) did his own paint prep and didn't know enough or care enough to do a good job. I would say that it has nothing to do with temperature changes based on my personal experience.
I was looking at a paint chip today & noticed that the paint on the car hasa very slight silver flake in it.The paint flaking on the roof does not! Si i would say its probably old. Another thing i noticed is that wehre it came off th roof the red primer looks like a dried "lake bed" .I don't knowif this is a good explanation or not or if it helps All in all looks like its a easy fix.
Like all cracked? Sounds like you need to strip it down to bare metal and start again. Doing anything over the existing paint is asking for further problems down the road.
It's easy to always blame product or someone else in the paint industry. Most of us on HAMB are not dummies. You guys are brilliant for the most part. That's hot rodding! Let me tell you what happened to me. I converted an old school bus to a motor home about 28 years ago. I replaced some of the windows with metal panels and sanded everything all down and primed it properly with 2000 non-sanding epoxy primer after washing the entire bus with lacquer thinner from top to bottom. I did not strip it to bare metal. Then I properly applied three coats of single stage fleet color, all within the the open time window. I did this in nice 70*-80* weather, medium humidity and lots of help. What a job! One day that very next winter, it got down to -10*. I went out to check something and I noticed that on the sunny side of the bus ALL of the paint on the metal I had replaced was on the ground! This happened every time it got below zero. The sunny side would flake off in sheets in various places down to bare metal. I know from experience the bus company primes raw buses with zinc chromate which adheres very good. Last year we were out west before we went to Florida for the winter and it got below zero again and it flaked off in sheets on the sunny side again. Every time, it would come off clear down to the metal!!! I think it's a thermal shear. The metal shrinks more than the paint and off it comes. If the bus stays heated inside it doesn't flake.
[QUOTE="Montana1, post: 10867968, member: 259066" Last year we were out west before we went to Florida for the winter and it got below zero again and it flaked off in sheets on the sunny side again. Every time, it would come off clear down to the metal!!! I think it's a thermal shear. The metal shrinks more than the paint and off it comes. If the bus stays heated inside it doesn't flake. [/QUOTE] No offense but it is still a paint or prep issue. The heat or cold might cause those issues to rear their head but they are not the primary reason for the failure. It gets down below -50 here and I have never seen it cause paint to fall off a vehicle. If the right products are used and the proper procedures are followed the thermal cycles that a vehicle will see under normal climatic circumstances will not cause properly preped and applied automotive paint to simply fall off a vehicle something else is wrong.
I don't have any answer for it other than what I quoted. I've seen this on other vehichles too that I didn't touch. I know it stays on at 50 below, but I don't have an answer except go to FL. for the winter! lol These buses were made with steel that is coated with what's called "paint grip", a special process to make the paint grip to it. Back then they could still use zinc chromate primer from the factory, like airplanes use. It shouldn't let go. That's why I didn't sand it down to the bare metal. However, some of the original paint is still on there since 1973! It's interesting though, the Maroon is what lets go, NOT the Silver or Black. It all has the same base preperations. Of late though, I've been using lacquer primer because of the expense. It seems to be holding up fine. Oh well... I just keep fixing it every once in a while.
So how many times has the paint fallen off this thing? How many times has it been repaired? Each time the same way ?
& where's the pictures? ? ? After 26 posts, thread needs at least 2 pictures minimum : 1) Picture going fast. 2) Picture parked with pealing paint. 3) Pin-up or swimsuit model next to pealing paint ok for 3rd picture.
I once had a 52 Olds the I could not keep paint on the roof. The paint was bad on the roof when I got it, not down to bare metal but popped off in dots of different sizes at a few locations. I stripped it, treated it with metal etch, primed and painted (then current industry standard). The next spring when it came out for the summer you could see it popping. (stored covered in unheated barn). Had the car for about 10 years. Prob painted the roof 8 times. Always popped in the same spots, never to bare metal. Did the newest process when one came out, still popped. Sold the car.
The first complete paint job was in '89, last patch job was last year ('14) above the windshield, above the windows, and above the rear door. I've completely repainted it twice over the years and patched things up about four or five times here and there. The roof is white fleet color over school bus yellow and has never come off in 25 years! On the last total repaint in '95 I used Ditzler clear coat right over the top of single stage fleet color and that held up the best. I used "Western" brand fleet color, I think it was made by Martin Senior. In '11 I just did the lower half Silver because rust was creeping up on things. The paint build up is getting kind of thick in some spots, but it still hangs on. Remember this thing ain't no show piece, but it is presentable. It's always the Maroon on the sunny side that flakes off when it gets below zero.
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