Non Mech Join to Aluminum

Weld? And there are solder preps that allow soldering to aluminum. ...Jim Thompson

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| 1962 | The only thing bipartisan in this country is hypocrisy

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Solder / welding is a good idea, though I'm not sure if low temp solder (ie not tig welded) is ok if this is for a protective power earth. Where I am soldered protective electrical earths are prohibited.

"Ken Dunlop"

** Expensive, difficult and not as reliable as using a fitting.

Seeing as it is only a "chassis" what the heck is your problem with making a small hole ?

BTW:

Why use the American spelling for "aluminium" when you are posting from Australia ??

.... Phil

One can solder - even using tin-lead, but it alloys like crazy and can leave a "dent" in the surface where the solder was employed. One can weld; spot weld or standard weld.

Hi Robert, Have you actully used the aluminum solder and fluxes with any success? I remeber years ago trying to get the 'aluminum solder and flux' to wet to a piece of aluminum.. It was a complete failure.

Is the aluminum alloy a issue?

George H.

I still have a partially used reel of Alu-Sol that I bought probably in the '70's.

It worked well for soldering to Aluminium, though of course you would need a high wattage iron to solder to a chassis.

Alusol seems to be available still - for example

"Aluminum chassis" means a component that accepts all manner of mechanical fittings. So, why do you want to not use a mechanical fitting?

Rivet, weld, self-tapping screw are possibilities. Simple contact will NOT work (aluminum oxide is too good an insulator). I've used some kinds of fittings that take an electrode paste that inhibits the insulator growth from atmospheric oxygen.

Jim Thompson wrote in news: snipped-for-privacy@4ax.com:

those are garbage. I've tried solder-it Aluminum solder paste,and a commercial aluminum soldering flux.

even welding is not simple.

--
Jim Yanik
jyanik
at
localnet
dot com

What I had success with was a block of "something" (flux-laden abrasive?) that you scrubbed off the oxide at the point you wanted to solder, then, with your 300W iron you finished the connection :-)

Welding is easy if your spot welder has enough ooooooomph ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
      The only thing bipartisan in this country is hypocrisy

When I was a kid I managed such connections with the help of many 40V power supply capacitors. Sharpen the wire's tip, electrify both ends, close eyes, and jam the two together.

On a more serious note, it's probably better to use a mechanical connection. There are many aluminum alloys and the ability to solder them varies from difficult to nearly impossible. Some alloys may appear to solder fine but later corrode or shatter.

--
I won't see Google Groups replies because I must filter them as spam

Umpteen years ago (40?) i used some special aluminum solder and flux that worked very well and did not have the alloying problem that use of tin-lead has. That special solder had (hold your breath LITERALLY) cadmium in it. Use of ordinary tin-lead solder works better with some fluxes than others (do not ask as i do not remember); the trick is to break thru the oxide on the surface. Once that is done, the aluminum seems to soak up the solder like a sponge! Do not think the alloy has much to do with the process.

and

ux

.

ed text -

Thanks Robert. I did a bit of googling after asking the question... (perhaps it's better to google first?) I did find some sites that said that the alloy type did matter... in particular 6000 series alloys were said to be very hard to solder. Since 6061 seems to very common I wonder if that was part of the problem. I'd done lots of soft soldering and hard soldering to SS, brass, copper... I had plenty of heat and cleaned everything well before starting... Sand paper and all. But no Cadmium!

George H.

I wondered about that - but would not be convinced unless you could provide evidence.

At materials practicals (Nat Sci Part 1A 1968) we were given a cadmium wire. On stretching the wire one could see the crystal grains. The colour of the Alu-Sol seems similar, and when stretched the surface takes on a rough appearance also. Perhaps I will find a chemical test forthe presence of Cadmium.

Warning Bill Robinson! Cadmium fumes are extremely toxic!!!!!!! Sandpaper can break the oxide, but..it re-forms rapidly and the chance of soldering is back to "normal" (miserable) by the time you get the iron on. The oxide film must be broken under the flux which keeps the oxygen away from the aluminum (that is the "secret").

OTOH - you could look it up for yourself.

Ed

My (old) Alu-Sol works very well. Current composition Alu-Sol appears not to contain Cadmium. Some solders contain Cadmium.

That's all I have found out. All the rest is hearsay.

Cadmium sulphide is yellow, lead sulphide is black, silver sulphide is black - makes a simple test for Cadmium in solder difficult.

I successfully soldered regular PbSn solder to aluminum by scraping vigorously under a drop of engine oil and then quickly soldering in the oil drop.

What do you mean by 'non mechanical'? What sorts of operations/devices are you ruling out?

--
Paul Hovnanian  paul@hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.

I have been using that technique for over 50 years without the oil. It takes a lot of heat because the Aluminum conducts the heat away fast. Rub a blob of solder vigorously with a hot iron until it bonds. Then solder whatever to the blob.

You can also flame weld Aluminum but it requires a talented craftsman.

John Ferrell W8CCW