Help-gas welding

[69 Fl. Bronc]

Never tried this before but i have 4 1/2 in. holes in my hood.Bought 1/8in. brazing rods to fill them in. Seemed easy enough But I could not get the holes filled in. Flux coated rod. Too big? Any tips would be apperciated. thanks, mike

 

[br0nc0xrapt0r]

I hope you mean four 1/2 inch holes, it's kinda hard to make that stuff stick like that, the way to do to would be to add a small backer to it like pennies

 

[70_Steve]

Gas welding is completely different than brazing. I would think it's pretty difficult to fill a 1/2" hole with brazing material without having the whole thing sag and fall out. And yes, 1/8" rod might be a little big if you're trying to get that kind of control.

 

[needabronco]

If your gas welding a hole that big in your hood, you'll also warp the crap out of it with the amount of heat your putting into the metal.

 

[Pa PITT]

ME TOO ...I say you'll warp it like crap...This is not my field but going into body shops for 30 years looking at different jobs ..I'D say put some thing under it and pucky over it all ....I liked a primer ...Epoxie ... called Feather rite..it smelled like bondo when sprayed ...it would cover 36 grit scratches ...
2 parts ...It covered crazing...........with it you didn't see the circle ...
It was not a DUPONT product ...Evercoat as I remember...

 

[lars]

I've done a lot of oxyacetylene gas welding (as opposed to brazing). No way will you fill a 1/2" hole without major warpage. That can be dealt with using a body hammer and a bucking bar. But brass won't work in any case. I'd rather use a MIG, but if I was gas welding I'd want 1/16" rod, max. Any bigger and you'll put too much heat into the base sheet metal trying to melt the rod.

 

[69 Fl. Bronc]

Thanks, guys.Time to go another route.

 

[malcolmzilla]

My 2 bits, as I cut, patched, warped, re-cut, rewarped and spent way more time trying to fix a "decent" steel hood... Just buy a new steel or fiberglass one and get right to prep and paint. Unless tinkering is part of the fun.

 

[69 Fl. Bronc]

Thanks malcolm but this ain't fun. ;D There is a new hood in my future,but not now.

 

[malcolmzilla]

Agreed, even assuming my 20+ hours of time cost nothing I had $100 of filler and highbuild into mine to get it "close" enough.

 

[Wyflyer]

You can fill the hole with brass if you use some kind of backers. Those nifty knock-outs from electrical boxes would work well, but be sure and grind them down to shiny steel first. A penny was also a good suggestion, since bronze welding rod loves copper.
The bronze will melt at a lower temp than steel filler rod, so if those are your only choices i'd go with the bronze. Using either method your going to warp your hood.
If you have access to a mig welder that is what to use because although it is intense direct heat, it can be spot welded then cooled quickly which will help prevent warpage. No matter which way you go, use a backer to fill the hole instead of welding rod only.
Another option is lead/solder which isn't done much anymore but is can be done with much less direct heat on the panel which will limit warpage.
To sum it up, anything will work, but you need to choose the method that will do the least warping damage.