Welding up trim holes

[horizontallyopp]

I did a search and didn't find the topic covered, however feel free to point me to any existing thread.

I want to weld up the trim holes in 4 areas of my car:
1. bumpers (deco strip holes)
2. hood (badge holes)
3. decklid (badge holes)
4. rockers (deco trim)

I likely won't get to the last one until I actually tackle repainting the whole car. However, the other 3 I can do and just get the pieces painted (or paint them myself).

What are some techniques for welding up trim holes? For the bumpers where the backside is not cosmetic, I have heard that if you put a nail through the hole and use the head as a backer, it's easier to weld up and then grind down. However, for the hood and the decklid, the backside is cosmetic, what to do? Differences in techniques between using MIG and using brass brazing?

Thanks,
Keith

[SP2]

I wouldn't want a nail contaminating my welds. I would just clean off all the paint and start building bead around the inside of the edge until it's closed. But it would be better to trim up a small piece of steel, hold it in place with a magnet to tack it once, then weld it shut. The small holes you can just buzz. For the cosmetics on the inside, you can carefully grind with dremel tool accessories. Either way you need to prime and repaint those areas.

[sfoster13]

you can use a copper backing plate and mig weld directly onto the copper. you can buy something like this:

Welders Helper 3X3 Set Flat/Curve/AngleCop Plates

Or, just go to home depot and buy some copper piping and flatten it to use as a backing. I recommend you practice on some scrap metal first to get the technique down. pretty easy with a little practice. just remember to manage the heat well on the panel you're welding on (use an air compressor to blow air on the panel).

[Fishcop]

Originally Posted by sfoster13

you can use a copper backing plate and mig weld directly onto the copper. you can buy something like this:

Welders Helper 3X3 Set Flat/Curve/AngleCop Plates

Or, just go to home depot and buy some copper piping and flatten it to use as a backing. I recommend you practice on some scrap metal first to get the technique down. pretty easy with a little practice. just remember to manage the heat well on the panel you're welding on (use an air compressor to blow air on the panel).

Ditto. I used some copper plate flattened out and then used magnets to keep the copper in place.

Some other advice... the sheet metal on the bonnet and real lid is really susceptible to deforming during welding. Wind your welders settings to a medium level, use short bursts and keep a wet towel close to cool it off quick. Better yet, spend a weekend doing it - just one hole at a time allowing the whole panel to cool down each time. Use a flap wheel to dress the welds, not a grinding wheel (and again, watch out for too much heat).