soldering aluminum

[JIMMIE]

I need to solder to an aluminum tube for an electrical connection. I
was hoping I could tin the Al and then latter solder a copper wire to
it. I have tried most of the solders for Al with little succes. From
what I have read Al will actually take tin/lead solder quite easily if
you can clean and keep the oxide coating forming. I have a glove box
that I may be able to do this in but I need to know what gas I should
use.

Jimmie

[Bruce In Bangkok]

On Sat, 20 Jun 2009 05:18:38 -0700 (PDT), JIMMIE <jimm...@gmail.com>
wrote:

I used to solder ground lugs onto an aluminum chassis using a regular
soldering iron, solder and a small stainless brush. Melt a puddle of
solder and then keeping it liquid scrub it onto the aluminum. The
stainless brush removes the oxidation under the melted solder and the
solder adheres.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

[Andrew Mawson]

"JIMMIE" <jimm...@gmail.com> wrote in message
news:ae358825-b739-4aee...@j20g2000vbp.googlegroups.com...

The technique is to clean the aluminium, then solder through a puddle
of high temp oil - I use silicone oil only as I have some left over
from a photocopier. You will need to form a bead of solder on the
iron, and then scratch the aluminium through the oil with the iron
tip.

The issues with aluminium are twofold: a/ it is highly reactive so
oxidises as fast as you clean it - the oil keeps the oxygen at bay. b/
It is highly thermally conductive, so you need a powerful iron to get
the local bit to soldering temp

AWEM

[dca...@krl.org]

On Jun 20, 1:18 pm, JIMMIE <jimmi...@gmail.com> wrote:
but I need to know what gas I should
> use.
>
> Jimmie

Argon is the most inert gas. Nitrogen is a close second. CO2 is not
inert at welding temperatures, but should be fine for soldering.
Natural gas would work, but it is flameable so I would not advise
using it. Ditto Propane. Or do as the others have suggested, and do
the tinning under oil or solder.

Dan

[JIMMIE]

I have used the suggested methods using oil and solder but they are
not suitable for my needs. The solder only bonded to the Al along
scratches made on the Al. I am going to try some CO2. I figure a few
small pieces will yield enough gaseous CO2 to displace the air in the
glove box 100 time over then I can use a rotary tool to remove the
oxide and conventional soldering procedures. Im am not interested in
soldering two pieces of metal together at this point. I only want to
tin the AL which will allow me to solder a conductor to it using
convential means later on in the constuction process.

Jimmie

[Martin H. Eastburn]

A high tin solder will solder much easier as well.

In fact, you can in most hardware stores find in the soldering / brazing
area - a silver box - for soldering Aluminum.

I've done both - puddle of solder - with a 150W black beauty iron and used
the special tin solder with flux. The flux provides a seal.

Martin

[dca...@krl.org]

Yes, dry ice ought to work well. I also thought burning something in
the glove box might work to get rid of the oxygen.

Dan

[Tim Wescott]

That would only get the O2 down to where that particular material won't
burn, which isn't necessarily as low as you'd need to get to make sure
that Al wouldn't oxidize.

Not that I know what the _right_ answer is, mind.

--
www.wescottdesign.com

[Carla Fong]

JIMMIE wrote:

I'm surprised that nobody has mentioned All-State #509 soldering flux,
available through Esab.

Works like a charm soldering copper to aluminum, among other things.
Pretty aggressive stuff though, so be sure to clean it all off after
finishing the solder joint.

Data sheet at
<http://products.esabna.com/EN/home/filler_metals_catalog/filler_metals_product_detail/q/display_id.id4367f2a9749c48.85935339/category_id.1123/path.filler_metals_allstate_fluxes_allstate_509>

Carla
An armed society is a polite society. Robert A. Heinlein

[Jon Danniken]

I've done the "scratch under a pool of molten solder" technique, and it
works fine. Clean up the Al as best as you can beforehand.

Jon

[Martin H. Eastburn]

And tin solder works better than lead or electronic solder.
You can buy it at the hardware store in the brazing and welding area.
Also on-line.

Martin

[Bruce In Bangkok]

On Sun, 28 Jun 2009 20:40:23 -0500, "Martin H. Eastburn"
<lion...@consolidated.net> wrote:

>And tin solder works better than lead or electronic solder.
>You can buy it at the hardware store in the brazing and welding area.
>Also on-line.
>
>Martin

Back in the days of tube radios when the chassis was grounded I used
to use regular resin core solder, the same stuff I was soldering wires
with, to make connections to an aluminum chassis. Just rubbed a spot
with emery cloth to get it shiny and puddle some solder onto the spot
and rubbed through the molten solder with a little stainless brush. I
don't know how strong it was structurally but it certainly held a
solder lug to make a ground to.

>Jon Danniken wrote:
>> JIMMIE wrote:
>>> I need to solder to an aluminum tube for an electrical connection. I
>>> was hoping I could tin the Al and then latter solder a copper wire to
>>> it. I have tried most of the solders for Al with little succes. From
>>> what I have read Al will actually take tin/lead solder quite easily if
>>> you can clean and keep the oxide coating forming. I have a glove box
>>> that I may be able to do this in but I need to know what gas I should
>>> use.
>>
>> I've done the "scratch under a pool of molten solder" technique, and it
>> works fine. Clean up the Al as best as you can beforehand.
>>
>> Jon
>>
>>

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

[Martin H. Eastburn]

No doubt Bruce - I was into steel chassis and finally the light
weight Al ones. I said better. Tin is the issue - electronic
was 63/37 and the like. 37% tin.

When you buy Al solder, you get special fluxes that etch oxide
and keep air off it.

Martin

[Bruce In Bangkok]

On Mon, 29 Jun 2009 19:37:07 -0500, "Martin H. Eastburn"
<lion...@consolidated.net> wrote:

>No doubt Bruce - I was into steel chassis and finally the light
>weight Al ones. I said better. Tin is the issue - electronic
>was 63/37 and the like. 37% tin.
>
>When you buy Al solder, you get special fluxes that etch oxide
>and keep air off it.
>
>Martin

True.

I was simply trying to point out that sticking something to aluminum
is not "rocket science" but can be accomplished with normal materials.
Now.... if it were some sort of structural joint it would be a
different story..

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

[JIMMIE]

I finally got around to trying soldering Al in a CO2 atmosphere and
the solder took well but my setup is a little awkward to use because
my gloves for my glove box are a little stiff. I also found I need to
vent my box as the pressure built up from the dry ice evaporating
tends to push the gloves out of the box. I think I used WAY too much
dry ice. The object soldered was a small AL rod about 3mm in diameter.
After the process was completed it was soldered succesfully to a brass
tube in a normal atmosphere.

Jimmie

[JIMMIE]

On Jun 30, 12:27 am, Bruce In Bangkok <decypher.addr...@sig.line>
wrote:

> On Mon, 29 Jun 2009 19:37:07 -0500, "Martin H. Eastburn"
>

I have tried various solders/fuxes that are suppose to allow you to
solder to Al. In my case this means tinning the Al so that it can be
soldered to easily by a relatively unskilled person. None have
produced a suitable bond for this.

Jimmie

[Bruce In Bangkok]

On Sun, 5 Jul 2009 07:38:52 -0700 (PDT), JIMMIE <jimm...@gmail.com>
wrote:

>On Jun 30, 12:27�am, Bruce In Bangkok <decypher.addr...@sig.line>

Without knowing your usage I'd think that bonding the parts using an
adhesive would be satisfactory (depending on area of bond, of course).
They have been "gluing" airplane bits together for some years now :-)

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)