Mystery brazing rods

[chunkolini]

An odd one.
I was donated a pile of gas welding and brazing rods a while back, Free, my favourite word.

But, some of the brazing rods are a bit weird. They are the same colour as standard (silicone bronze?) rods, maybe a bit stiffer when you try and bend them. I use Siffbronze milkshake flux, and do a lot of brazing.

Usually I dont have any problems, except with the 'mystery rods'. When heated and fluxed they dont melt properly, they just seem to oxidise, and skin over instead of floowing cleanly. Any body got any idea what they are.

Chunko'.

 

[KTMMICK]

Probably welding rods.........

 

[hotrodder]

I take it there's no identifying marks on any of 'em? Nothing stamped into the filler or remnants of a paint colour code on the ends? IIRC the old colour codes for 'silicon bronze' (C2. copper, zinc, silicon) is/was blue. Nickel bronze (C5) is/was green but there are a bunch of other less common flavours too

The common oxy fuel brazing fillers have a lot of zinc in 'em while TIG/MIG brazing fillers don't and have a higher melting point. Might explain it if the flux is being cooked before the filler melts?

Copper silicon TIG/MIG filler (C9) is just copper with around 3% silicon, the other common on is phosphor bronze (C11). Again a bunch of other less common flavours but all have a melting point around/slightly above 1000C IIRC

Try 'em with the TIG set...

 

[chunkolini]

Hotrodder, that sounds like a good idea. I have tried Tig brazing with ordinary brazing rods with no success. Will try this next time I am in work.

Chunko'.

 

[chunkolini]

Had a go with the Tig set, a bit better but not useable. The I cleaned the grime off the tube, they are 'Aluminium Bronze' by Murex/ Saffire, the exact numbers/letters are on a scrap of paper on my workbench. Doh!

What are they for? and are they worth anything??? I have three tubes of them

Chunko'.

 

[hotrodder]

This the stuff? There are some other aluminium bronze flavours but all are recommended for use with AC for the TIG process.
A bit more info here (listed as sifalbronze #32 here)

Oh, like most copper alloys they ain't cheap! (1st google hit random price)

 

[Shox Dr]

Chunko. What Dia are they? I might consider taking a few off you, if you like

 

[chunkolini]

Hi guys
It looks as though I have been lucky, £70.00 per kg indeed, so much for them being a waste of space.
They are 3.2mm in diameter, make us an offer for a few.
I will probably put them up as a job lot on fleabay.

Chunko'.

 

[Shox Dr]

Too big, thanks all the same.