Brazing pinholes vs. replace sheet metal

I'm told brazing pinholes after media blasting is nearly as robust as cutting out the rot, shaping and welding in new sheet metal, but only half as time consuming (as in expensive), but only in areas that don't show. Opinions?

 

It's often hard to get paint to stick well to brazed repairs. I can remember several old cars I've had where the paint just bubbled up and flaked off of the few places where there were brazed repairs, and it looked really ugly.

 

If you tin the brass, like when soldering, or doing lead work, paint will stick.

 

Problem with brazing is that it's difficult to get the flux, which paint/plastic filler/lead won't adhere to. You can sandblast the brazed seams and it'll be good, but simply grinding won't do. I once bought a chopped Model A coupe and found that the top had been brazed, not welded, on

 

do it once. do it right. weld.

bondo will lift over time when it covers a braze. I can't really think of anywhere in automotive bodywork where brazing is the best way to do it.

or are you talking about a floor or something else?

 

Brazing works very well and cheap thrills hit the nail on the head when he said to tin the brass......

 

Area surrounding the pin holes has lost thickness and will be weaker, so it depends on where it is.

 

Yep, dead on. I just has a car that had a hole brazed shut. Only crack on the entire hood was where this braze was. It had been in paint for maybe 5 years and the owner said it was cracked a good 3 of em.

 

If your not going to fix the metal correctly then just Bondo over the pin holes and hope it stays.

 

Everywhere they're brazing will be under stainless/chrome or a rubber weather strip. The only place I can think it might ever show is around some tight curves in the door sill corners. From what I can tell, they're putting epoxy primer over it, and will bondo over that (very little bondo).

 

Thats horrible advice. Read - If you're not going to fix it correctly, fix it wrong another way.

They?!?!?!??? A shop is doing this!!?!?!?!???!

 

Yes, it was a really rusty car, and I have just enough money to focus the sheet metal work on the parts that will show, and I have no shop skills.

 

I didn't mean like OMG you aren't doing this and are paying a shop to. I meant OMG I can't believe someone that is getting paid for a job would braze some holes shut becuase they wont show.

IMO thats half assed.

 

Must be old timers. My old boss used to do stuff like that, and he was a great customizer, back in the day. He never used the MIG welder i bought back in 83, thought it was black magic, or something, welding without a flame!
It will work, but not the best way to go about it. Tinning it does help, as does epoxy over the brass IF it's cleaned and roughed up enough.
I wouldn't do it now, but 20 years ago........

 

Yup. If you were doing it yourself, on the cheap and the only equipment you had was a torch and a sandblaster, and were learning your own set of "shop skills", yeah, give it a go.

But, pay somebody to do it wrong? If it's under chrome or rubber is it not going to pop? Why do you, and the shop owner, think it isn't going to pop/rust/blister under chrome and rubber? That's why it rusted there in the first place.

You need to take it to another guy to do the work...

 

Why braze when you can weld with steel. I have over the years fixed a couple of holes, maybe two or three on an otherwise good panel. I still have that car and it is amost ten years with no sign of any trouble. Actually it is the car in my avatar.
Used to use bronze back in the day. Works well if cleaned and ground and will last at least 5 years without trouble. Welding with steel will last a lifetime. If in doubt I drill the pinhole out and then weld it up. I have a mig welder only because NHRA rules required it for roll bar in steel construction. Otherwise I gas weld. Always hated mig welders myself because I think they are for people who cant weld. Anywaythat is another topic. Any repair is better than none but you might ask how much you are saving by the bronze. If an extra $100 will make it perfect now is the time to spend it. It is however better than nothing. If the first application over the repair is kitty hair bondo, then the normal stuff it will last much much longer . I quit sending out body work. I hate it and it is not my skill but I learned the hard way NO ONE will take more care to get it the way you want then yourself. I get it to the ready for sanding, spot putty and paint stage and they take it from there.
Don

 

FWIW, even if the braze doesn't show, it will make a "void" in the paint that will allow moisture to creep under the rest of the paint. A paint job should be a non interrupted coating to prevent moisture from getting to the metal, this braze will only serve to weaken this seal.

 

I have some bodywork that was brazed and is bubbling. What is the best way to fix it? Some have mentioned tinning it with solder or lead. Would that be easier that grinding the brass out and welding it back up. It appears to be just spot welded with brass.

 

Well depends on the hole sizes. I find that another good use for a Tig welder is you can braze with it. If the damaged areas are that large, I would make some patch panels and mig or tig them into place.

Never had issues with braze, some folks say lead will give you paint problems to. I say use a self etching primer, then a good polyester filler primer like Slick Sand or Upol, a few coat of that will seal off that stuff rather well. Prepare to sand alot. 320 is reccomended with it and I would stick with that. Lots of work, but in the end the finish is better for us non auto body people. Look up my 32 Ute on hamb under 1932 Ford Roadster Ute and you will see what I mean. The rear quarters are pieced together and came out pretty good with that method.

If you get away with using zero filler (usc clearcoat is best) then you are a phenom!

 

silicone nickle bronze rod, put down with a tig, is a proper repair on pin holes, Epoxy likes it, works great.

 

That's my point... I should have been more clear.

If your not going to fix it right why even waste your time doing anything more than completely half assed...

 

I'll second that... I'd be looking for a second opinion if I were you

 

I can, not that it matters.

 

What?

Brazing holes shut - Wrong

Your advice.

Bondoing holes shut - Wrong

 

Although I have done it in years past, I wouldn't do it today. You will eventually have corrosion problems from the use of dissimilar metals, brass and steel.

 

is this some guy working out of his garage or a real shop? either way, take your car to someone else.

 

If the holes are blasted and clean, tell them to use a copper backing bar, tight behind the hole, and fill pinhole in with MIG(or TIG). I have a flattened piece of 1 1/2" copper pipe that I use.

 

Geez Are we talking about pin holes or patch panels? If they have a torch why not weld the pin hole?

 

exactly

 

If you can fill the holes with brass/bronze, why wouldn't you fill them with steel and be done with it? I mean, really, how much cheaper would it be to melt in brass/bronze then to melt in steel rod? And if there are a lot of holes to fill, how is it not as fast to weld in a piece of sheet steel? Am I missing something here? Gene