Need Brazing Rod Info

I don't braze often, but occasionally I come across some cracked cast iron or a copper pipe in the house needs to be fix (improved?).

What's a good, all-around choice rod for brazing?

On eBay, I've found some Bernxomatic rods:

1) the Blue NS-3:
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the White WB-5:
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What about brazing steel? Does anyone have experience with the Bernxomatic SWR-10 rods?
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As far as I know, Bernxomatic might be a sucky brand! Looking to build on the experience of others before diving in.

One of these eBay orders for 15-20 rods would probably last me a year or two. Do these need to be kept in a rod oven like 7018 electrodes?

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I buy low fuming bronze brazing rods in 1/16" locally, and heat them and dip them in a can of blue flux when I'm using them. The bare bronze rods do not need any special storage, nor does the can of flux.


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Grant Erwin

Thats piqued my interest I think I remember by late father stick brazing with an old (even then) arc welding plant the sticks had a coating presumably flux is that kit still available? Derek

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It has been over a month and I never got a response. Maybe it was deleted because of that spammer. Anyway, I'm still curious to learn an answer.


"jp2home" wrote:

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Bernzomatic makes OK stuff, but it is a bit pricey because they sell it in small quantities. It is meant for hobbyists.

The differences in the flux color on the rod is because of different working temperatures, and rod alloy. According to the Berzomatic website the blue NS-3 is a Nickel silver rod, stronger, but also requires a higher temperature to make it flow.

The WB-5 is a standard bronze brazing rod. Easier to work with, lower flowing temperature, not as strong.

You can buy comparable rods at any welding supply store, but usually in larger quantities.

I prefer to use separate rod and flux. It allows me to control how much flux I use. You buy standard Low Fuming Bronze brazing rod and a can of flux powder. Warm the end of the rod with the torch and dip it in the flux. The flux will melt and coat the end of the rod.

A good basic flux is Peters No.2 Blue. It works well for most steel brazing jobs. They also make a black flux for higher temperatures, which works well on cast iron.

Reply to
Ernie Leimkuhler

Hey Ernie,

Glad to see some of the regulars returning to the board. Hopefully, someone finally got that spammer! :)

Your information was what I was looking for. I haven't brazed anything since I took my welding courses back in 1989, so all I remembered seeing were the packaged, precoated rods. I forgot all about dipping that rod into a can of white powder.

Could you give me some pointers on brazing?

Do I get the steel red hot? If memory serves, that is too hot for the rod to stick. When is a good indicator that the surface is at an adequate temperature?

The brass (?) does not wick into the cracks of the metal like solder does, right? Seems like the "brass" forms a bead-like deposit on top of the brazing area.

When I walk into the welding store to get this "black flux" (?) for cast iron jobs, is that what I call it? I hate it when I go into the welding supply store and don't know what I'm talking about! :)

I probably got a lot of the terms wrong up there (see the "?" spots), but I tried! Please correct me on anything that isn't right.

Regards, Joe www.joesweld> I prefer to use separate rod and flux.

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The hottest the steel should get is a dull red. Bright red is hot enough to burn the zinc out of the bronze. If you get white powder around the puddle, that is Zinc Oxide. This will reduce the flow of the brazing alloy by increasing the percentage of copper. It will also make the bronze redder. The flux should flow over the surface ahead of the bronze, lifting the oxides, so the bronze can bond to the steel.

Use a soft flame with a carbon feather at least twice as long as the inner cone.

You don't need to dip the rod in the flux every time. The flux will flow for quite a distance. The goal is to use as little flux as possible, so you have less to clean up.

The bronze should form a soft round smooth bead, with no ripples.

If you use Manganese Bronze rod and no flux, then you can get what looks like a weld bead. I did a AWS cert in this about 17 years ago. It is used for pipe and steam fitting.

Any welding supply store should carry some brand of high temp brazing flux for use on cast iron. Peters Black flux is my favorite, but there are others.

BTW do NOT use any Phos Bronze rod on steel or iron. The phosphorus can lead to long term cracking problems.

Phos-Bronze and Sil-Phos-bronze are used to braze copper and brass alloys with no flux. They are self fluxing.

Reply to
Ernie Leimkuhler

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