Technical Tig brazing

Hello guys new member with quit a bit of welding skills in tig and mig but zero in brazing. I picked up a 24 model T that I have found some holes in under old bondo. I have been reading that brazing is bad because of the flux and fillers and paint not wanting to stick to it, I'm wondering what the opion is for tig brazing with silicon bronze rod or is there a better option. My other thought was to use a copper backing and just tig the holes closed with ER70S2 filler rod . Thanks for any input

 

I have TIG brazed with silicon bronze rod in a non-stressed application fixing a deuce quarter panel. Its a little tough to keep the rod from dripping off before the base metal is hot enough to absorb the rod. It does significantly reduce distortion.

 

Cool good info, I'm thinking i can pre heat with propane torch then just get after it to keep the filler from dripping off because the base metal isn't hot enough

 

I do it all the time. It's no big trick.

You use a much lower amperage than welding, so the risk of distortion is far lower.

The issues with adhesion with brazing are not from the bonding material, but the failure to remove all of the flux.

 

One weldor to another.....don't try to re-invent the wheel.
Just get a piece of copper (or thick Alum.) and weld the holes up.
Prolly be stronger and less headache than " learning" how to fill a hole with a new technique and strange weld material to fill a hole with weaker material! IMHO
6sally6

 

So with Tig that sounds like the way to go. All argon zero flux . I wanted to get some opions before I got after it, thanks

 

There is nothing wrong with brazing, as you said it’s the flux that’s the problem. Properly clean braze is fine. No issues with silicone bronze tig. Just clean well after any process.

 

So the question is, if you have a TIG, and the skills to use it, why on earth would you want to fix a hole in sheet metal by brazing? The brazing process has enough issues connected with it, why would you even bother when you already posses a much better process? Coming up with sheet metal to form a patch can't be that hard.

Fix it right, weld the hole closed. Leave the brazing in the history books.

 

Yup, 100% Argon. Make sure both sides of the metal are as clean as you can get them.

 

Yeah I'm thinking this would be my best option because I know my welder and setting required for sheet metal. I'll most likely get after it with 3/32 er70 and good chunk of 1" aluminum suckimg heat out as I go

 

What issues? Can you elaborate?

I have been using silicon bronze on body panels for about 15-years, on about 50-cars. That is a combination of MIG brazing for tacks, and TIG brazing.

There has not been one single issue with any one of those seams.

My daily driver has about 15-feet of TIG brazed seams, and that includes the fuel tank!

 

This is the reason I asked. I Tig stainless titanium, aluminum, carbon steel.. zero auto body experience so thats why I asked. But I mentioned tigging them up with er70 and I will most definitely go that route after all the replys I have got i figured I would give silicon bronze rod a try never messed with it but sounds like I should leave it alone and fill the holes with er70

 

I’ve done a good bit.
OEs now use it on panel joints but using a MIG process. I’ve dug into several European cars with bronze seams.
I normally make a new piece for rust but for random holes dropping some bronze in a hole is super easy.
Those old screw holes for “yanking out dents” fill up easy.
I can planish it out smooth and takes less heat. Never had an issue.

 

Don't let people scare you off of trying new things. Grab some rod and try it on some scrap.

It is not at all hard, and won't be for you, as you already know torch, rod, and puddle control.

 

Yup. My experience is exactly the same.

 

I'll keep you updated on what I do. I'm just up north from you in Sacramento

 

Sweet!

 

Most of my auto-body experience was gained back in the 70's, back then most body men believed brazing was a sub-standard method of repair used by knuckle-draggers who didn't have the talent or inclination to do the job right because no matter what you did to remove the flux that brass would always come back to haunt you.

This leads me to the next question: Who are you doing this work for, you or someone else? I promise you no customer will want to see brass anywhere on their vehicle if it wasn't put there by the factory.

 

^^^^^ find me in same category ^^^^. I’ll mig it up with copper backing before I’ll fuck with brazeing

 

The reasoning is lower chance of distortion. He's not some rube who lacks skills and only has a torch and a box of brazing rod.
My own experience and I'd say most of the guys here with brass in non structural non stress spots is that the acid all too often comes back to beat your butt no matter how much effort you put into cleaning it off.

 

Hate to say this, but it is not 1955, 1965, or even 1995.

Technology and practices change.

And it is not Brass. It is Silicon Bronze.

 

Yup, and with MIG and TIG brazing, there is no acid.

No acid, no "brazing problems", which is the origin of the "brazing is bad" mindset.

 

I very much realize it's not the 70's anymore, that the auto body repair/repaint industry has changed dramatically over the years with new products and procedures but none of that matters when it comes to changing the mindset of a customer, and the customer is the one paying the bills.

Let's just imagine that a customer brings in a '32 Ford roadster to have a quarter panel replaced, you gonna weld it on or use bronze? Just because a new product or procedure is "acceptable" by the industry doesn't mean the customer is going to agree to it. (if you really want to see fireworks shoot out of someone's ass let the customer catch you gluing that quarter panel on using "panel-bond").

 

You will when you have your new car repaired to OE specs. Silicon bronze that is, which is the subject of discussion. Not the same as brass with a torch.
Todays knuckle dragging body men mig weld everything (or panel bond) Funny how things change.

 

I really don't know didly about the fine points of panel replacement but If the guy/shop that's doing it knows their stuff I'm sure as hell not going to tell them how to do it. As long as its quality work that's done correctly so be it. Just my 2 cents.

 

This is my car and I would be using silicone bronze filler rod not brass rods

 

Here is a pic I found in my phone of my TIG work. Mild steel. 095 wall with 1/16 er70s2 filler. The main reason I wanna use silicone BRONZE filler rod is, it wets in very smooth and nice as well as keeping lots of heat out of thin sheet metal. When I get home from work I will take some pictures of what my simple shop garage is

 

Ever see the brazed structural joints on a jaguar?

 

No I have not, I have a feeling I'm going to Tig every hole, crack and filler panel with silicone bronze rods on the entire body. I would love to see them if you have a link or pics

 

I know this discussion is in regards to filling holes, maybe I missed it but can patch panels be butt welded with the Silicon Bronze as well?