Aluminum soldering

Good shit; I've used it.

Lord Valve

1100. Any idea of which is better?

I was also planning on getting some aluminum flux and some Zn/tin solder from McM-C. Other suggestions welcome.

Thanks

George H.

-------------------------- You might try posting this to rec.crafts.metalworking. There's a lot of experienced, knowledgeable, and helpful people there. Art

I have some Harris Al-Solder 500 that I picked up at the local welding supply house.

It works great. The MSDS has all sorts of warnings about the flux, so don't use it for incense. It obviously etches the aluminum.

My only complaint about it is that the flux can't get too hot, which means that you pretty much have to use an iron, and it's not obvious to me if I can just use it on an iron that's already tinned with lead-based solder, or if I need an iron just for these jobs.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

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Cool thanks, any idea what Al alloy you used?

George H.

Thanks Art, I've never been there... I do enjoy metal working.

George H.

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ttdesign.com

Thanks, I think a separate tip is a good idea. I was going to use a gas torch and a hot plate. But maybe a Weller gun to 'tin' the Al plate.

(I'm still waiting for an alloy.. I read somewhere that 6xxx's were not so good.)

Maybe 1100 is the 'cleanest'?

George H.

I've been using Welco 52 for aluminum.

The "standard" aluminum solder has Cadmimum as a part of the alloy; the fumes are deadly. A "secret" to soldering of aluminum is to break thru the oxide surface film and keep it from re-forming. Once done, (ordinary tin-lead) solder will flow underneath that film as if it was water; it flows FAST and alloys with the aluminum FAST making the aluminum plate there thinner. Virtually any "flux" will do - as long as i keeps the oxygen away from the aluminum.

Thanks Art, I've never been there... I do enjoy metal working.

George H.

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I'll second Artemus' suggestion of rec.crafts.metalworking

(You just have to filter the politics & survivalist threads....)

Alloy? ALLOY? We doan need no steenking ALLOY!

I just use it (Alusol) for soldering copper ground wires to the aluminum chasses found on certain guitar amps. Being guitar amps, the alloy used is probably the cheapest crap available. Reynolds Wrap?

Lord Valve Toob Dood

1100 has the best thermal conductivity and corrosion resistance, and the lowest strength. As the alloy number increases strength increases at the expense of conductivity and corrosion resistance. Soldering will give you the T0 (fully annealed) heat treat condition regardless of what heat treatment you order, so use that yield strength in your design calculations.

I'm curious how hot this will get in use, e.g. are you making a heat sink?

Alumiweld?

Disclaimer: I've only watched their infomercials on late-nite teevee, but it looks pretty good. ("Well," the little voice said, "it would, wouldn't it now?") One scene shows laying a bead onto a soft-drink can, so .032 should be do-able without distortion.

The web site does note: "AlumiWeld is capable of repairing copper and brass to aluminum."

Available over the counter at Harbor Freight (et al., presumably). I need to get some to play with ...

--
Rich Webb     Norfolk, VA

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OK McM-C order placed for some 1100 and 3003 Al sheets.

Thanks

George H.

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Oh it just sits at room temperature. I'm making an acoustic Fabry- Perot cavity. The aluminum plates on the ends at as 1/4 waveplate AR coating. Thye kill the cavity Q for a certain wavelength/ frequency. It works OK with 'goop' between the brass and Al, but I'd like better coupling.

George H.

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Interesting. I'm guessing it's Zinc/aluminum. McMaster-C sells two types of Aluminum solder. Zn/Al and Zn/Sn(tin)

I bought the Zn/Sn... it's lower temperature.

George H.

Not necessarily. Soft solder (60-40 let's say), with a sufficiently reactive flux (they're usually based on ammonium bifluoride, nasty stuff!) will do little. Typical aluminum solders (based on tin, zinc and aluminum alloys) melt over 600F, where you'll see at least some change in the aging characteristics, resulting in a softer product. Brazing (over 900F), usually with zinc-aluminum alloys, will anneal the base metal; these require particularly good control because the aluminum base alloy softens around

1100 and fully melts around 1200.

Tim

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