To answer some of your questions: When I lift my welding shield the crack is there. 4043 is not an option. No this 32mm to 6mm we have not done this before. 4943 can it be anodized and have no color change? Yes I did preheat the blocks - I made everything the same temp Ok what I have done: After I w...

still cracking.jpg When I'm finished with the first run it has a crack all along the toe of the weld against the thin material. So I decided to give it a second weld all along the toe to cover up the crack - it still cracks but much less - still not exceptable. I cant use 4043 filler cause it must ...

That 200 degrease that Mick is talking about is it Fahrenheit or Celsius?

The thick lug is 6062 and the thin one is 6061.

This is what I did to try and get the heat to distribute a bit more evenly. It still cracks.

I'm using straight argon.
yes i do fully button off when stopping to get a new rod.
joint design problem - yes that i suppose is possible but how would one design it?

I do keep the thick part flat at the bottom when I weld it.

Ok so you can't see the crack on the photo but it has cracked on the bottom of the weld. Maybe the 2 materials aren't heated up to the exact same temperature? Can that cause the cracks - I don't think so.

This is the problem one - the one that cracks. I do pre-heat. As soon as I stop welding to get another rod it starts cracking - I can see the crack when I stop - so therefore post-heating wont stop the problem either. The thick material is 30mm welded to about 6mm. It cracks all down the side of the...

This is 40mm thick - this I do pre-heat it also doesn't crack

This is 32mm aluminum that I weld without pre-heating - it does not crack.

How do i paste a photo here? so i can show you some welding

I am an artisan welder at Southern Spars South Africa. We manufacture yacht masts and supply the world. Yes I definitely pre-heat the thick material, must admit I haven't post-heated. I am using 5356 filler rod. Cant use an oven either because masts and x-beams are somewhere between 5 and a 100 mete...

some of our aluminum tig welds tend to crack when we weld the thicker aluminum eg. 30mm thick welded to 5mm aluminum. Would it be better to weld it with pulse?