Which is better? Brazing rods with flux Or without flux

You need safety-silv 56 for this project..... Melts at about 1500°F....

Bronze filler melts at much lower temps... Bronze also doesn't wick down into the joint as well as silver does...Bronze does build up easily but it's not great at being a thin layer down inside the joint like you want....


Agree, very strong way way to assemble tubing. Here's some of my work on .035 wall steel tubing. My test joints were almost unbreakable.
 

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I looked at the spec for safety-silv 56. It melts at 1205*. Don't think that will work if the header is baked at 1400* to cure the ceramic coating as a local company claims on their website. If I go with VHT spray on then the header gets heated to 700*. My only reason for the ceramic coating is for rust prevention. Otherwise I would leave it as is. Not thinking about trying to control heat radiating off the header. I have used heat wrap on the exhaust on my sailboat. So I am familiar with it.

I have used Harris silver solder. It melts at 435*. One thing that I really like about it is that I can put a small piece and flux where I want it. Then heat the surrounding area until it melts and flows into the joint. I don't over heat or under heat this way. Will the safety silv 56 and the other safety silv's do the same thing?

I can do some practice pieces. This stuff is expensive at $8 to $10 per rod.
 
For lower strength brazing pre-fluxed LFB is my goto
When i need more strength i got bare silicon bronze and 20 mule team borax
 
What is "LFB"? I tried searching for it and didn't get any hits.
 
Rust prevention on a car like this is probably a non issue. You’re going to be working on it all the time and can keep an
eye out for any problems.

It’s way more likely you’ll need to repair a crack than a rust hole. Ask the coating place what you’ll need to do for any future repairs, maybe they can give you a scrap piece to practice on so you’ll know what to expect.

John
 
What is "LFB"? I tried searching for it and didn't get any hits.

Google LFB brazing rod. Here's the first one that popped up:


Looks like "low fuming bronze".

Ted
 
I think it's worthwhile to note that the filler follows the flux. As long as I can generate the heat I need where it's needed and get it clean, and get flux into the opening, I can braze it.
 
Bought some Safety Silv 56 and flux off ebay. Should get it sometime next week.
 
Use the coated rod till you get proficient. Easier and quicker for the beginner. Then experiment with bare rod, just be sure to clean the bare rod with steel wool before welding to get the oxidation off. I use bare silver solder wire and it must be clean prior to use.
 
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