Cutting aluminium with a hard anodised finish both sides

[AdrianH]

Only hobby stuff, but I had an issue the other day cutting some 3mm aluminium, every now and then I would go from a good cut to part cut and then back again it did not seem to matter about speed, air pressure good etc.

I noticed that I had lots of hard flaky bits floating in the water tray and could only guess it was the remains of the anodising and the flakes were at times sticking and blocking the cut path?

the metal started off as a large blank front panel from a 19 inch equipment cabinet, it just happened to be the correct size that was needed for someone at work.

So just wondering if anyone has cut anodised aluminium before and had similar issues?

Adrian

[weldguy]

I don't expect the anodizing would have anything to do with your problem as it is only a .001 thick or so typically. I have had the cut path close up behind itself when cutting aluminum and steel before but it was because of a worn nozzle and/or too slow of a cut speed.

[AdrianH]

Fair enough was just a wondering what was going on. It could be to slow as not a professional set-up.

Adrian

[sphurley]

Anodizing does not conduct, how do you have the return clamp connected? Did you grind some anodizing off and attach to that?

[AdrianH]

I just stuck a weight on the aluminium to keep it down on the grate. The clamp is to the table. The pilot arc did not seem to have any issue starting, or at least I did not think it did.
I will probably not use the same plate again for a few years if at all. But thanks to you both it is something to think on.

Adrian