Thread: Welding Aluminium

From the alum welding I've witnessed, it always gets that black carbon around the weld. Mates have always used a TIG instead of a mig for alum welding.

More info. Argon is the right gas. Use more in wind, less in sheltered garage area. Preferable when welding alum to be sheltered as possible. Sounds like u need more power than 40%, less than 90%. Trial and error for the power level is the key. Practice on each type/thickness of metal to get the levels right. I'm a learner myself so that's what I have to do.

Black build up is normal - cleans off fine.

Thin Alloy is hard to MIG as need to get temp just right otherwise not penetration or total penetration (melts/burns). Keep the Gas up to it and shelter as Rat suggests.

Practice helps - even get some thinker material to start with and get the hang of it there as more forgiving then back off the power a little and move to thinner material. I found laminating 6mm alloy a breeze and build technique and confidence that helped with the thin stuff.

Also for shelf unit had you considered using the Bunnings system with the plastic corner jointers inside alloy box section. I had looked at this option myself as neat, would have some give, and easy to fix if needed and no brittle corner welds. Use alloy welding to maybe make draws. Rivet and glue top to unit.

Let us know how you get on as tempted to make my own soon too.
Keith

IME you need to crank the current (and gas) up higher than when welding steel.

The ally needs to be completely clean.

Black residue is normal.

If you can, it helps to clamp a block of brass on the other side of where you are welding when you are doing thin stuff.

What MIG unit are you using?
The biggest issue with MIG ally is wire feed. As you experienced if the feed is wrong youll be burning tips or birdsnesting!

Ideally you want a nice smooth 4-roller drive with burnback control.
Use a short whip and keep it straight.
Teflon liner for less friction.
0.9mm filler is easier to use than 0.8,make sure you are running a 1.0mm tip.

With regards to your specific problem, if the wire is burning back into the nozzle it seems like you need more feed. You gotta work quick with 3mm Al, the wire feed (current) is much faster/higher than for 3mm steel. If the job is critical it can help to use brass/steel heat sinks but also a run-on pad before the critical weld. Youll find the cold start on 3mm ally can be a hassle if you are only doing short weld.

I enjoy MIGing ally, but it is certainly more finicky than steel.

S

Blow by blow pictures please Dave

Never know, I might learn something

Urgghhhh I hate welding....

I'm using a Trade Tools Direct MARS 180 - TradeTools. I can weld steel quite nicely with it so it can't be too bad.

I'm doing very well at creating nice beads on top of the ally but nothing that bonds with either bit of metal.

So far my biggest concern before starting - feeding issues - hasn't been a problem at all. The wire comes out nice and consistently and hasn't got stuck once.

I'm hoping to steal some time with a mate next weekend and see if he can help me out. I'm also going to buy a new bit of ally to experiment with as well because my bit of angle is looking like the surface of the moon now.

Mark - I will doco my drawers when I start... if I start.

Thanks for all the replies. I'm sure I'll get there with more time experimenting.

Another method I find gets great results, find someone u know that welds aluminum brilliantly, bribe them with cash or booze and get them to weld it for u. I do it all the time