VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Heat shrinking metal

Hi
My 1930 SR is having a bare metal respray. The shop says that there is evidence that just behind the passenger door the body was impacted and the reshaping was done by shrinking the metal back into shape. Apparently this is done by alternatively heating and hammering. It seems to have produced a very good result, but I am curious to know if this was a common technique in the 30s. I should add that the car is RHD and probably comes from Uruguay. Any information welcome
Thanks

You can find information on the internet and demonstrations on youtube. Sometimes the shrinking is done without hammering. I sold two rear fenders for a 33 that were badly dented and they were straightened with heat only. They looked perfect when done. I have no idea if it was being done in the thirties, but very few people are doing it in the auto repair field today.

I have used this method in working on my 65 M*****g....My Dad taught me how to shrink sheet metal when I was a kid in the 50s using a soft flame torch and a body hammer for shrinking........I use body solder as well....A few customizers use both methods....If done well, you can never tell it was repaired....

Mac

Before the use of plastic fillers (Bondo) heat shrinking was the method used to repair dents. Lead was the filler of choice both at the factory and body shops. I was taught to heat shrink in the 60s by a body man. It was getting rare then as filling with plastic was faster.

I have tried this old fashion technique. However, I have not mastered. You use hammer and Dollie to raise the low areas and then shrink the high points. Shrinking high points with a torch and cooling quickly with water. Today a shrinking disc is used instead of the torch., but has the same effect. Repeat the process and refine the surface until 95-99% done. It is very time consuming and requires patience, perseverance and technique and touch. I repaired a 31 fender dent using no bondo! Really. It took about 40 man hours of labor and looks as good as new. Fascinating lost art.

Like Jmm says shrinking works great but is nearly a "lost art". Like Chipper I was taught metal shrinking in the 1960s. In my case I took 3 semesters of evening adult education body repair classes.

The body shops I showed my '36 PU to said they could "straighten" it. Their definition of "Straightening"? Bondo slathering which is no more than plastering followed by shaping with a cheese grater.

Old school hammer and dolly body repair is really very learnable and doable IF you can find someone to demonstrate the techniques. The tools are certainly inexpensive.

If you're interested I can send you by email a "cartoon" of the shrinking technique I was taught.

raywaldbaum@gmail.com

Not many body shops around here can use a disc or a torch and a hammer and a dollie, slap hammer or even a rasp for body solder....I taught the twins who live in my neighborhood how to use all of these and their pick up looks pretty good....I just finished fitting the rear valence on my M*****g and had to modify it a lot to get it to fit...My 32 Chevy had a small place on the rear of the body, near the right side at the top of the rear pan. Fabricated a patch and used body solder to finish it....

Mac