On Wed, 12 Feb 2014 19:30:28 +0000, David Billington
wrote:

On 12/02/14 12:44, John B. wrote:
On Wed, 12 Feb 2014 02:18:02 +0000, Bob Lowe
wrote:

replying to Ned Simmons , Bob Lowe wrote:
news wrote:

On Tue, 11 Feb 2014 18:51:04 +0700, John B.
I did quite a bit of welding on masts back in the bad old days, mostly
on boats 40 feet and up as well. Halyard winch bases and radar mounts
were the first things that came to mind.
--
Ned Simmons

Okay Ned, I have a question...I don't know how far back your bad old days
were but in the 50's when I needed some aluminum welding done I always had
it done by Heliarc, as if the gas welding flux hadn't been developed
yet...I really don't know this for sure. But now that I am retired my 'To
Do' list has grown to a couple of life times long and I can't get
everything crammed in. I have I think at least 3 gas welding outfits, the
regular industrial, a mid sized venturi air type and a little Map
Gas-Oxygen affair. I haven't gotten around to teaching myself how to weld
aluminum. I see the flux coated gas rod and this is my question....could
this be an easy way to get started on this? Or could you recommend
another starting point? I don't want to bother with getting into the Mig
welding area.

Thanks,

Bob Lowe
I learned to gas weld aluminum in 1951 and it was a bitch. My
suggestion is to arc weld anything thick enough and buy a TIG for the
thin stuff.

The problem with gas welding, and to some extent TIG welding aluminum
is that the metal doesn't change color when heated. You are heating
the parent metal, waiting for a puddle to form and suddenly the whole
thing falls on the ground.

The technique is to keep poking the spot where you intend the puddle
to form with the filler rod. If all goes well you will poke and a bit
of rod will melt off and there's your puddle.
I got shown how to weld aluminium with gas back in about 1985 by a
welding instructor, he wasn't a real welder but taught the course and
could passably gas weld aluminium. I had already taught myself to OA
weld so was good at steel and I noticed that there is a subtle change in
the surface appearance of the aluminium before it drops on the floor and

Yes, a subtle change :-) The new welder doesn't usually see it ...
until too late :-)

that is when to add the filler to keep the pool under control. After
about 10 minutes I was welding Al better than the instructor. Never had
any issues with glare either, the flux just seemed to go water clear and
wet the surface when near welding temp and I was fine with the standard
gas welding filters, maybe the flux in the UK is different. Not gas
welded Al for maybe 20 years now as have had TIG to use for Al but don't
weld Al that often anyway.

I've always sort of wondered about that. We learned using a paint on
flux and the usual green lens welding goggles and never a mention of
glare from the flux.
--
Cheers,

John B.