Hello All!

First off, I want to say that I have been reading this site for a long time and it is packed full of great information and I want to thank everyone for their input. It has greatly helped me in progressing along with my 70 chevelle.

I have read nearly all of the old entries pertaining to plug welding but still had a couple questions I hope someone can answer.

#1 - When plug welding trim moulding holes (5/16-3/8") I understand to use copper on the back of the hole. Do you start the weld at the outer edge of the hole and work to the center? I would assume yes but wanted clarification.

#2 - Do you complete the plug weld in one pass or in a few small passes?

#3 - I ground down the moulding rivets in the doors but am weary about what's left of the rivets causing the paint to crack later on down the road in the form of the rivet that is left flush with the door. Should I drill out the rivet and plug weld it, weld right over the top and grind flush, or just leave it?

Thanks again for you input!

Jason

start your weld on the upper edge of the hole, gravity will help flow the puddle. One complete pass unless the hole is larger than 1/4". The factory rivets are actually welded on trim studs that do not protrude through the panel, if you've ground them off they are gone, nothing to worry about.

I actually posed the question of using copper as a backing to my welding shop ... and they said no way, it would contaminate the weld area.

What's the verdict?

Another way to do it (over 3/8"), is to weld horizontally across the top edge of the hole. Let that cool, then weld horizontally across the previous weld. This will build up enough metal to fill in the hole. I've found that moving around quicker side-to-side trying to fill these holes will help keep from burning through.

Neal

I punched out a bunch of plugs with a rotex punch, laid a piece of masking tape cross the back and stuck the plug in the center. Worked slick.

Cam

You could also place a dime or nickel sized piece of sheetmetal on the backside of the hole and weld it in place from the outside. Coat the back of the weld with Por 15 when you're done and make sure the Por gets inbetween the plug and the original metal.

Copper wont hurt the weld zone.

Hey guys, thanks for all the info. I'm actually looking forward to starting up some of the body work this winter. Oh wait, suppose I should have heat in the shop....but then I wouldn't be able to afford body panels. Hmm, wonder which will come first. HA!

Just something to add but normally the paint gets removed around the hole and whatever else is there down to the bare metal. I would then take a drill bit but smaller than the hole in the car and just lightly run it around the edges of the hole with the drill bit chucked in a drill so that the edges of the hole are clean and bare metal.
Jim