Was I given the wrong brazing rod?

[mhorowit]

I wanna learn to braze.
The brazing joints I"ve seen shine up like brass.
I went to the welding supply and told the man I wanted to braze 4130.
He gave me some flux and a pound of rod (All-State 4130-T, P/N 69701140).
I went home and tried it. It didn't melt like I expected and the base metal got almost white before the rod 'flowed', something I'm trying to avoid. When I took a wire brush to it, it didn't gleam like brass.
GOOGLING for the P/N says it's a low alloy TIG welding Rod.
Now I'm a beginner so I'm unsure of myself, hence, even in the face of three facts (the joint didn't shine up like brass, it took a lot of heat, research shows it to be a TIG welding rod) I gotta pose the question: This is the wrong filler isn't it? - Mike

[3Dreaming]

Re: Was I given the wrong brazing rod?

What i've used the most is 1/8" flux coated bronze rod. Around here you can get it at the farm supply stores. Tom

[jgerard]

Re: Was I given the wrong brazing rod?

Yeah, I think the guy at the welding shop didn't understand you when you said BRAZE 4130. You don't even use 4130 rod when welding up 4130 on aircraft. It makes for a brittle joint. Most people in the industry use ERS70 or 80 which is a mild steel rod. Brazing is a low temp method of joining metal together. 4130 rod will not melt at those low temps. Like 3Dreaming said 1/8" flux coated bronze rod is what your looking for. Most hardware stores stock it. It is normally about 2/3 the length of normal welding rod, and has an obvious coating of flux on it that will melt quickly once under the flame of your oxy-acc torch.

I guess you have a pound of 4130 rod you can now use to hang parts up with for painting.

Get this book "How to weld damn near anything"

http://www.amazon.com/gp/product/0760318085/104-2271800-1138332?v=glance&n=283155

Here is what I came up with on the All-state 4130-T

http://www.esabna.com/EUWeb/AS_handbook/596as9_32.htm

[mhorowit]

Re: Was I given the wrong brazing rod?

I guess you have a pound of 4130 rod you can now use to hang parts up with for painting.

Nah, he'll take it back. - MIke

[Guest]

Re: Was I given the wrong brazing rod?

I wanna learn to braze.
The brazing joints I"ve seen shine up like brass.
I went to the welding supply and told the man I wanted to braze 4130.
He gave me some flux and a pound of rod (All-State 4130-T, P/N 69701140).
I went home and tried it. It didn't melt like I expected and the base metal got almost white before the rod 'flowed', something I'm trying to avoid. When I took a wire brush to it, it didn't gleam like brass.
GOOGLING for the P/N says it's a low alloy TIG welding Rod.
Now I'm a beginner so I'm unsure of myself, hence, even in the face of three facts (the joint didn't shine up like brass, it took a lot of heat, research shows it to be a TIG welding rod) I gotta pose the question: This is the wrong filler isn't it? - Mike

Sounds like the rod I get for TIG welding brass

[paulnuss]

Re: Was I given the wrong brazing rod?

The store clerk was/is an idiot, and can't read his own products manual. I wouldn't ask any advice from him ever. The filler wire he sold you was type 4130 steel, for fusion welding, not brazing. All-State calls it 4130-T with the T meaning for TIG welding, now officially named GTA welding for Gas-shielded Tungsten Arc Welding. (As an aside, there are occasions and weldments where one would use type 4130 TIG willer metal to weld type 4130 base metals. That is why it is manufactured. I used to sell some of it for manufacture of WACO aircraft components. The manufacturer fully heat-treated the welded components after the welding process for maximum strength and ductility.) And of course, more commonly, mild-steel fillers are used to torch-weld (and TIG weld) 4130, using parent-metal dilution with the filler metal to accomplish a suitable joint. A flux is normally never used with TIG welding, and very, very seldom with oxy-fuel torch welding. When welding, base metal pieces and filler metal all melt, then freeze back together to a common mass.

Brazing is very seldom used on our small airplanes, with only a very few exceptions, due to far lower strength of the joint. Only the filler metal melts when brazing, the parent metal pieces being joined do not melt. A brazing flux is designed to be chemically active in the same temperature range as the meltng range of the brazing filler metal, and there are many different ones, so be use to use the correct flux. The manufacturer's manual has lists of compatible brazing metals and the recommended fluxes.

[Guest]

Re: Was I given the wrong brazing rod?

The store clerk was/is an idiot, and can't read his own products manual. I wouldn't ask any advice from him ever. The filler wire he sold you was type 4130 steel, for fusion welding, not brazing. All-State calls it 4130-T with the T meaning for TIG welding, now officially named GTA welding for Gas-shielded Tungsten Arc Welding. (As an aside, there are occasions and weldments where one would use type 4130 TIG willer metal to weld type 4130 base metals. That is why it is manufactured. I used to sell some of it for manufacture of WACO aircraft components. The manufacturer fully heat-treated the welded components after the welding process for maximum strength and ductility.) And of course, more commonly, mild-steel fillers are used to torch-weld (and TIG weld) 4130, using parent-metal dilution with the filler metal to accomplish a suitable joint. A flux is normally never used with TIG welding, and very, very seldom with oxy-fuel torch welding. When welding, base metal pieces and filler metal all melt, then freeze back together to a common mass.

Brazing is very seldom used on our small airplanes, with only a very few exceptions, due to far lower strength of the joint. Only the filler metal melts when brazing, the parent metal pieces being joined do not melt. A brazing flux is designed to be chemically active in the same temperature range as the meltng range of the brazing filler metal, and there are many different ones, so be use to use the correct flux. The manufacturer's manual has lists of compatible brazing metals and the recommended fluxes.

Golly!

Paul you are right on. I assumed that the rod was at least a brassy color, no way it's steel. I just looked it up on the esab site.

I got some brassy rod one day to tig weld a brass fitting together and thought that may have been similar to what Mike got.

Mike, Paul is right find a new supplier. There is no reason why a welding supply should confuse brass with steel.

Dave.

[mhorowit]

Re: Was I given the wrong brazing rod?

Here's yesterday's brazing project. Thanks to Bob G. for the plans. - Mike