Aluminium Bronze

[Speedy Builder5Participant @speedybuilder5]

Just spent an hour making a complicated composite elbow using some 1/4" dia copper tube and a piece of Al bronze to form a nipple to a 1/4 BSP gland nut.

First one turned out a bit too short, so spent a bit more time and turned up a second nipple.

Went to silver solder the tube into the nipple and THEN I remembered that Al Bronze (If that is what I have) doesn't silver solder (or lead solder).

A few choose words selected !!!

Bob

[Speedy Builder5Participant @speedybuilder5]

[Nigel BennettParticipant @nigelbennett69913]

It can be silver-soldered, but it does usually need some specific flux for the job. I recall mixing some aluminium flux with silver solder flux for a job at work a long time ago and it worked well. Luker in his current Fire Queen series in ME shows what looks like an excellent join in aluminium bronze.

[Speedy Builder5Participant @speedybuilder5]

Thanks Nigel

From model engineering pro boards:-

"As the content (of aluminium) increases so does the need to remove the aluminium oxide. A special flux is often recommended. This special flux has a higher content of chloride.

Make your own by adding 25% by weight of kitchen salt (sodium chloride) to your conventional flux! Use it in the same manner."

That is an easy one to try out tomorrow. I will let you know.

[not done it yetParticipant @notdoneityet]

How about the ‘lumiweld’ rods/wire for the job? I use it quite often for all sorts of jobs. No flux just scratch the surfaces to get the filler to run.

[Speedy Builder5Participant @speedybuilder5]

Quick update – EF flux plus 25% of common salt worked a treat to wet the joint surfaces and allow the silver solder to flow properly.

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