OT- Square Flux Cored Brazing Rod?

I know this isn't the place for welding questions so if it needs to be moved please do.

The man that runs the local scrap yard gave me a couple of pieces of brass rod that were mixed in with some common brazing rods. As you can see from the photo they are square shape and folded from a strip of flat brass. The middle is packed with white powder that I would guess is flux. I melted a little of the rod and it acted like common flux.

I have been brazing for a long time but I've never seen any rods like this. I learned to braze on cast iron oil field equipment and tractor parts using plain old brass rod dipped in a can of Brazo flux. We always had lots of pump housings and engine blocks that had "hard water problems" this time of year.

I just wonder if this is something that was common?

Terry

New one on me, but I can see why it was done that way, ...a simple low volume method of including ''plenty of flux'' inside a tube,

All in all, pretty damn cool

Yes, ... once-upon-a-time, ... various bronze alloy brazing rod was produced in a "square" cross-section.

Worked just fine, ... but seemed to disappear from the marketplace when round, flux coated brazing rod became commonplace.


I still prefer an un-coated rod, and a simple Borax based flux powder, in-a-can, ... like the trusty old "Marvel Mystery Flux".

Not that I think it was any better than pre-coated rod, ... but just for the nostalgic factor.


.

I've never liked coated rods alone, ....always liking a tin of flux to hand, if only for the start of the job.

When you melted a little of the rod, was there any lumps in it? Sort of reminds me of the "borium " rod used by farriers[guys that shoe horses] The Borium rods contain crushed tungsten carbide in a tube, Gives a horse a little traction on icy roads. I see it once in a while out in Amish country, And it's fairly expensive. A lot more sticker shock than you get buying some NI-rod. Dave [acme thread]

Thanks for those suggestions. I did some searching on Google Patents and saw several patents concerning tubular welding rods. Some were called composite rods and others were called self-fluxing. Most of the patents covered the machines to manufacture the rods. All I saw were more or less cylindrical. I have seen hard surface rods that were filled with alloy and Stoody was one of the early patent holders. I never found any information about the square shape of these rods. These are really too small to have any abrasive in the flux. It just appears to be plain flux.

I have used the flux coated brazing rods and they work pretty good considering. We always kept kept a can of flux handy cause it just seemed like there was never enough flux on the coated rods. A lot of the stuff we brazed was hard to clean so extra flux usually helped. It also seems like the flux on the coated rods would flake off once they were used a little. Anyway, old habits are hard to break.

Thanks again,

Terry