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Dropped my 39 dodges doors down to a supposed professional car blaster ,who was recommended! with clear instruction not to blast the larger external skin areas. This they did. But to my dismay blasted the interior.
So as we all know the skins have stretched,leaving large indentations in the doors which pop back when pushed back in line..
Can any one give me a step by step to shrink the damage back???? Or recommend a good forum.

Thanks
 

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Dropped my 39 dodges doors down to a supposed professional car blaster ,who was recommended! with clear instruction not to blast the larger external skin areas. This they did. But to my dismay blasted the interior.
So as we all know the skins have stretched,leaving large indentations in the doors which pop back when pushed back in line..
Can any one give me a step by step to shrink the damage back???? Or recommend a good forum.

Thanks
This is exactly why I dont blast a car,other than the god awful mess it creates.
First I'd try to locate a pair of doors so if I made them worse I knew right where to go to replace them.then I'd go to metalmeet or the allmetalshaping sites and find out everything I could about the shrinking disc and how to use it..Its a stainless steel plate you put on a grinder and run it back and forth over streched metal...shrinking it...
 

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Brian Martin,Freelance adviser
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This is why I have preached and preached with passion TO NOT SANDBLAST SHEETMETAL! And for that I have been beat up on a number of sites by guys saying it can be done so do it. :rolleyes: This is really sad, it isn't that easy to get 1939 Dodge doors, and it has put this guy in a terrible position!

The saddest part is many of the people beating me up don't even understand what is happening to stretch the metal, and why it is difficult to repair.

It is NOT heat as most believe and I at one time did too. The metal actually gets cooled when being sandblasted, remember you are blowing a lot more air than sand on it, so it gets cooled. I tested this myself, the metal was VERY cool to the touch when sandblasting it.

What is happening is the sand is acting like little hammers hundreds of thousands of little hammers, smashing into the surface of the metal thinning that surface. The SURFACE of the metal is getting larger just like thinning a piece of pizza dough. By this thinning and it being larger than the area under the surface it warps. Of course even if the whole area all the way thru the metal is getting bigger it is going to warp. But as I understand it, the top surface is mostly what is being effected by the tiny pieces of sand acting as miniature hammers.

I personally have no idea how to repair it as when it happened to me it was on a panel that I was making a sign out of (a 1928 Buick door) and I just caved and paved because it didn't matter. I personally shrank it with a large torch and water just to get it from oil canning and I covered the door in a gallon of bondo. As I said, it was a freebe give away sign I was making for store I worked with so it didn't matter if it was covered in bondo. The shrinking disc is probably the best bet as Mike said. But how do you shrink just the top surface of the metal? I don't know, maybe I am off base there and the shrinking disc is all you need. hopefully someone with more metal skills can come on here and shed some light.

Brian
 
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put up or shut up
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I think blasting is a great idea if they're good. Thing is, not a lot of places are good at it. We get stuff blasted and do the hoods and decklids by hand
in-house. Never have issues with them and they even blast the back sides of doors on the bottom for free, they blast the inside bottom of fenders for free and know where to blast and where rust is on hot rods. They're the best in Sac. Then again I've seen places destroy cars. It's not something you look up in the yellow pages.

As far as fixing it, metal work it the best you can then re-check the looseness of the skin cause it might tighten up a bit with some metal work. Then bust out a shrinking disk and do light shrinks repeatedly til it stops oil canning. Can also do lots of small tiny shrinks with a stud gun moving inside to out.
 
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