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Re: Brazing Brass

Posted: Wed Aug 22, 2018 9:04 am
by DavidF
I'm having more than a hard time understanding why timing would be critical. Aluminum bronze isn't new, and it isn't user friendly. It isn't generally used unless required, much the same as manganese bronze, which makes aluminum bronze look like a walk in the park.
If this bracket was built before 1909 then it would be highly unlikely to have been cast in aluminum bronze. Check out this pdf when you have a moment. biblical-data.org/MY_aluminum_Bronze.pdf

Here is a cut and paste from the encyclopedia britannica
Aluminum bronze, any of a group of strong, corrosion-resistant alloys of copper containing from 4 to 15 percent aluminum and small amounts of other metals, used to make many machine parts and tools. Because of their golden colour and high tarnish resistance, the alloys are also used for jewelry and in architecture. Their resistance to oxidation at high temperatures and to corrosion, particularly by dilute acids, makes them useful for pickling equipment and other service involving exposure to dilute sulfuric, hydrochloric, and hydrofluoric acids. They have strength comparable to that of mild steel and are used for such machinery as papermaking machines, brush holders and clamps for welding machines in the electrical industry, heavy-duty gear wheels, worm wheels, metal-forming dies, machine guides, nonsparking tools, and nonmagnetic chains and anchors. Aluminum bronzes can be welded by the metallic arc process and can be brazed (soldered with certain alloys) with special fluxes.
Awhile back a friend of mine dropped me off some brass scrap for my casting work. Most of it was just your typical red and yellow brass, but one piece quickly caught my eye. It had been broken in two by some sort of machine and the break was of an extremenly high shine as if it was polished.
So whats is this I though to myself. I tried some scientific testing of this beautiful looking stuff to try to get a better idea of what I had (if you consider hitting it with a ball peen hammer scientific) What ever this alloy is, it is impressive. Withstands multiple hammer blows barely leaving a mark, and does not file easily. I suspected it could be aluminum bronze so I started researching it a bit and became intrigued by its potential.
From my research and mindset I thought the bracket to be brazed in this thread would be a perfect fit for an aluminum bronze casting, although silicon bronze or yellow brass would be much easier to produce...

Re: Brazing Brass

Posted: Wed Aug 22, 2018 10:07 am
by ctwo
The building was constructed around the mid fifties. I'm not sure if that is the era this hardware was introduced. It's near the ocean.

Color looked a bit different than the two (three) different colors of brass plumbing parts I have. What are these typically made of? I stumbled across some last night cleaning up and feel like some redemption. OK, some of the plumbing parts are more yellow and have been machined into things like faucet stems and housings for that. Others are cast fittings like elbows and they look more copper color. Some of that gets black and some just stays a nice coppery color. I would say all that plumbing material is similar, but not quite the same in tone.

Re: Brazing Brass

Posted: Wed Aug 22, 2018 1:07 pm
by DavidF
The ones that are more copper color are probably the 85-5-5-5 Red brass. With the yellow its hard to say. Yellow brass can come out different colors when cast...

Re: Brazing Brass

Posted: Wed Aug 22, 2018 6:24 pm
by liveaboard
If you're coastal, someone might have used bronze. I had a beach house for a while and even stainless would rust unless it was the good kind.
Anyway, I presume it's dead now?

Re: Brazing Brass

Posted: Thu Aug 23, 2018 1:18 am
by Harold_V
Speaking of stainless---the 300 series---it has the potential to rust superficially unless it has been passivated. That process (chemical) removes any traces of free iron on the surface, and creates an impervious layer that, unless disturbed, prevents rust.

H

Re: Brazing Brass

Posted: Thu Aug 23, 2018 2:46 pm
by ctwo
liveaboard wrote: Wed Aug 22, 2018 6:24 pm Anyway, I presume it's dead now?
It was from a friend who maintains the building, so it could be resurrected. I told him, "You're in SF, find a welder..."

I'm sure nothing has happened.

Re: Brazing Brass

Posted: Fri Aug 31, 2018 10:25 am
by Magicniner
Bronze Wire, Argon, MIG, Job Done.
Check Sif Bronze for wire specifications and pick what suits you.