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jhowell
05-23-2007, 12:47 PM
So I've got this old 928 that I've been toiling away on for the past (almost) year. I finally grew some balls and cut out the quarter panel that needed replacing and got the new one fit and welded in place. Some I'm still a relative novice at this, the seams had larger gaps then I would have like but I managed to get them welded anyway. My problem is grinding don the welds to get them flush. It seems that the surrounding sheet metal bends inward and if I try to grind the weld too much, it grinds away at the sheet metal making it very thin. Obviously copious amounts of filler are in my future, but what I'm wondering is something wrong with my technique that I could possibly change in the future to be like the guy on Speed Network who can weld all day long without every using filler?

88GT
05-23-2007, 01:02 PM
So I've got this old 928 that I've been toiling away on for the past (almost) year. I finally grew some balls and cut out the quarter panel that needed replacing and got the new one fit and welded in place. Some I'm still a relative novice at this, the seams had larger gaps then I would have like but I managed to get them welded anyway. My problem is grinding don the welds to get them flush. It seems that the surrounding sheet metal bends inward and if I try to grind the weld too much, it grinds away at the sheet metal making it very thin. Obviously copious amounts of filler are in my future, but what I'm wondering is something wrong with my technique that I could possibly change in the future to be like the guy on Speed Network who can weld all day long without every using filler?
I use a cut off tool to grind them almost flat and folow up with an angle die grinder and a 3" 50 grit disc to finish. I stop shortly after I get therough the e-coat

Stanger
05-23-2007, 04:18 PM
It sounds to me like the seam was not welded flush and you are now fighting unlevel surfaces. I would just be careful not to grind the surrounding metal too thin. Apply some putty and forget about it. On your next panel take some more time to fit, use butt weld clamps if possible. You will get the feel for it and your seems will be much smoother.
Grant

John Kelly
05-24-2007, 08:53 AM
Nobody can weld all day on sheet metal and not use filler...unless they stretch the welds and metal-finish afterwards. Welding shrinks (thickens) and pulls, making valleys in compound curved sheet metal. This article might help:

http://metalshapers.org/101/jkelly/index.html

John www.ghiaspecialties.com

Lost in NJ
05-24-2007, 10:11 AM
Ah the old days when I was really clueless.

I know what you are going through. After reading a book and a lot of webpages, watching some videos, and working in the garage I have progressed to doing ok at metal work.

Here are some notes I wrote up:

http://home.comcast.net/~68c/Metalworking.htm

You can rent videos at smartflix.com.

jhowell
05-25-2007, 01:57 PM
You're quite right about the unlevel edges of the parts. I believe that is causing my problem and I had actually bought some of the clamps you were speaking of. Unfortunately, I had misplaced them and didn't use them. Live and learn I suppose.