From Newsgroup: rec.crafts.metalworking

I've gone for an Ali-MIG (Aluminum-GMAW) welding machine.

Lincoln Foundation book says all 1/16" = 1.6mm (apart from bigger for
bigger size).
I have only used 1.2mm wire - 5356 - some 5183.

At thicknesses of Ali plate of like 10mm and 12mm, reckon about
14m/min of 1.2mm wire.
(/ 14e3 25.4) ;; 551.1811023622048 ;; inch
So is 551ipm

By area ratio - which is exact guidance for steel - would be for 1.6mm
wire
(/ (* 14 9) 16e0) ;; 7.875 ;; m/min
(/ 7.875e3 25.4) ;; 310.03937007874015 ;; 310ipm

AI searched for me - it says
* 1.2mm more penetrative
* 1.6mm is softer more spread-out arc

With 1.2mm wire I wondered if fillet corner fusion was too much (!).
On T-fillet 10mm thickness definitely and Al-Mg (5000-series),
* edges plasma-cut
* plate much abraded (it was a recovered floor checker-plate)
* which I wire-brushed with a steel brush (no stainless wire brush)
There was quite a swirl of solid detritus circulating around at the
leading edge of the weld-pool, and I got a sense I was slowing-down
the weld to let it float-out and ensure fusion.

I tentatively thought
* I run much quicker on clean plate
* I suspect the very penetrative arc was melting-out contaminants in
the contact between the terminating plate and the continuous plate
in greater quantity?

I can macro-etch marine-grade Ali, to inspect the outcome.
I do want to avoid equipping up with MIG-torch / GMAW-gun which I
don't use.
Hence - anyone know the arguments on this and can advise?

I did break a weld in the wrong place and it took seemingly too little
effort. I suspect the slowed run-rate gives coarser structure which
is less strong (?).
I suspect I need to weld fast(er).
I like the idea of uniform penetration across the weld legs, and
running fast...

Anyone tell me if I can weld Al-Si 4000-series with a standard "push" wire-feeder if the wire is 1.6m / 1/16" ?
With slippery liner - PTFE or HDPE? (only met HDPE).
I have never MIG'ed 4000-series before.

Regards, Rich S
--- Synchronet 3.22a-Linux NewsLink 1.2