newbie just saying hello

[cammy9r]

hi, just registered today. I have a sip 150 turbo migmate and need help with my aluminium welding. I need to customise my bike frame to suit new design after a rather bad recent crash ops:
I read that the alu has to be super clean before welding, how do you get it clean, grinder? file or wire brush?
I also find that often the alu wire bunches up at the rollers even with the tension adjuster fully unscrewed.

 

[malcolm]

Hi, welcome to the forum cammy9r.

I'm afraid my total knowledge of setting up a mig for aluminium welder is on http://www.mig-welding.co.uk/aluminium-setup.htm . I think the most effective thing was changing the tip to an oversized one, although I changed the wire liner for a plastic one, and extended the liner towards the rollers at the same time. My wire feed seems to work perfectly now.

I've been filing the edge of the aluminium and wire brushing the sides where I plan to weld. I've found filing the edges to be very important - the edge is where the two sheets of aluminium need to mix, and a bit of oxide there really screws the mixing.

 

[Hitch]

Scotchbrite (green scouring pads from under the sink) also works a treat for cleaning aluminium prior to welding.

 

[cammy9r]

thanks malcolm and hitachimad.

used the set up in the forum and after wasting many miles of wire :roll: I managed my first strong welds. The welds which hold light duty mounting brackets i dressed back but the others for the petrol tank I have left.
Over all ugly, but passed the big rubber mallet test. A clean up and some nice shiny black paint should get it looking nicer.
I aslo found that keeping the earth clamp close to the area to be welded made a big difference, maybe due to the low conductivity of aluminium. But I think I will upgrade the earth clamp to something that has more surface area contact

Again, thanks guys.

 

[Hitch]

If you investing in a new earth clamp, get one that screws down, rather than the crocodile clip type.
The closesness of the earth clamp shouldnt make any difference.