When I replace my quarters I will step flange the mating point for welding. Because I expect to have some difficulty getting to the back side to weld that portion of the flange I was wondering about doing it this way. The step will be on the existing metal. The new quarter will sit in this stepped flange to create the joint for welding. I was considering punching holes along the edge of the new metal to plug weld through to the stepped flange underneath, sort of like a spot weld. In this way the flanged joint would be welded at the middle of the joint. Does this sound feasible in creating a strong enough weld?

That's how I did mine, but I didn't like the look of it after I finished so I ended up welding the entire seam where the new qtr meets the flange. I was worried that I wasn't going to be able to clean out the seam well enough and that the filler would crack. I'm sure that's not the preferred way to do it but boy, lemme tell ya, these qtrs are never coming off!! :eek: The seams were also more difficult to straighten out b/c of the amount of heat I used! graemlins/sad.gif Looks great in paint but one of the body guys can probably recomend an easier way.

P.S. I have a slightly used puncher/flanger tool that I probably won't need again soon!! ;)

Paul D.

Did you apply the body filler and then decided to change it and have to sand it off or did you weld before you had bondoed it?

I welded it up before I put on any filler. I just didn't like the look of the gap that was left after plug welding.

Chris:
On most flange tools (air powered) there is a punch just for that reason. I was told to punch a hole about every 1.5" and plug weld. I moved around the quarter to keep the heat down. Also, try using weld through primer on all sides of the flange and panel before you weld (only on welding area). After plug welding, I went back and stitched welded the seam just to be safe (not 100%). This was on my Chevelle, and there were no full quarters available at the time so it was a long seam to keep straight.
Zip screws also help keep everything tight as you go along. In some spots I also pushed slightly on the panel with a blunt object to make sure the the two panels were pushed together as tight as possible when welding. Take your time and it will look great!
Joe

You really need to fully weld the panel if you are going to "bondo" over it. Any seam unwelded WILL show up in time.

Practice, weld very small (1/4"-1/2") beads one at a time allowing the weld to cool naturally a LONG time. Really take you time, if you take the whole day to weld this, you will be ok. Weld a little weld, then go on and work on something else for ten or fifteen minutes before your next weld. If you sit there and watch it or cool it with water or air or something you WILL warp or shrink the panel all to heck.

Some people will recommend cooling, but this DOES shrink the metal. Unless your objective it to shrink it, DON'T COOL IT.

Thanks for the help guys. I always use the weldable primer whenever I join two pieces of metal. It must dry thoroughly but it's great stuff. My concern was what Martinsr pointed out, that the seam will show after bondoed. I think I will fully weld the seam in small increments and plug weld in an effort to avoid having to weld the seam on the opposite side.

I second Martin Sr's post, a seam will show, no matter how well/much you block unless the seam is continuous.I used patch panels on my coupe and I see the "ghost lines" through the clear coat. It absolutely drives me nuts!

Great advice has been given, use weld through primer, weld continuous by skipping around ,and I'd backfill the backside of the weld to keep moisture out, lessens the chance of rust erupting on the backside of your metals overlap.