The Stovebolt Site Forums The Shop Area Paint and Body Shop Can you anneal sheet metal without damaging it?

Hello!

On my previous post, I asked about how to fix a hole in a fender lip...thanks for the responses. Regarding that same fender lip, one of the holes someone drilled was also dented in about 3/8", and then kinda mangled/twisted. Since it's right on the surface of the lip, it's hard to get to behind, but I did the best I could with narrow body hammer and dolly. Although I've managed to straighten it a bit, there's still a ways to go. Trouble is, it seems that the metal has become work hardened...it does not want to straighten any more no matter how hard I hit it.

I've done some reading on body work, and recall hearing that you can anneal metal, or eliminate work-hardening by heating the metal to cherry red and letting it cool on it's own. Quesion is, can you anneal part of a fender without permanently warping the metal? Metal expands significantly when heated, and I'm afraid that the expansion may buckle the surrounding metal even more, and/or distort it in the area that I'm heating.

I could probably repair it by slapping some bondo on it, but I'd like to get it as close to perfect as I can before using the dough.

Thanks...

Chris

don't create more problems than you currently have, you're dealing with stretched metal, it doesn't have to do with work hardening, and over heating it will just blow holes .... sounds like that small section has been abused too much to simply hammer flat, any metal straightening needs to pretty directly "reverse" the direction of force that caused the damage, hard to do with creases .... if you can't fill it with weld and grind down both sides, you should cut out the damaged area and replace it, a thin skim of bondo is the last step to smooth an area, not fill damage

Bill

Bill -

That would have been my preferred approach (cut out and replace), but the truck in question is a '59 Apache, and the sheet metal is the lower section behind the rear wheel well (on the bed). I've looked everywhere, but I have not been able to find that area as a patch panel.

If you know of anyone who make it, please let me know.

Chris

none available, need to DIY

Bill

Shaping metal is not how hard you hit it, it is where you hit it. Although this book was written almost 60 years ago, it is still very much on point. http://www.amazon.com/Key-To-Metal-...automotive&qid=1295126182&sr=1-1 And of course you must remember you are working with a vehicle that was produced around the time of the writing. It also deals with metal shrinking. I would suggest reading the book before you do more damage.

Hmmmm, heating that metal is not gonna expand or stretch the metal out, its gonna do the exact opposite, its gonna contract or shrink.
Spot heating metal DOES NOT CAUSE THE METAL TO EXPAND IT SHRINKS!!!!!

Besides you wont see any real difference if you anneal it,plus the annealing process takes more then just a simple heating. Not worth the time and effort.

Try reading this. You ARE dealing with the same exact principles...Eric

http://www.chevelles.com/forums/showthread.php?t=333455

Thanks to everyone for their input.

Crenwelge - I don't *think* that I've damaged the area (at least I hope not)...it's a lot straighter than it was, and, given that there are no patch panels available, I have to do the best with what I've got. THANK YOU for the link to the book. I'd heard about it, but was not sure if it was still available. It's on order as we speak.

Sevt_Chevelle - thanks for the tip. I read in one book that to shrink metal, you spot heat it, then tap the area down gently with a dolly behind it to shrink it. I'm going to have to use that technique on another area where a previous owner tried to remove a crease with what was probably a framing hammer,judging by the outward facing dents.

Chris

Eric -

THANK YOU for the link to the Chevelle board! Outstanding information. I'll be practicing more in the next few weeks. I can only hope to get close to what you did with that fender.

Chris