Welding Tips and Tricks

Any tricks to get a clean cut? I've been cutting some 3/16" aluminum plate with my Miller 375 extreme. The machine cuts just fine but the edge is really grainy and rough. Suggestions?

Cutting with compressed N2 will help, but grinding disks are probably cheaper!

Every little bit helps, though. Do you have a good dryer in line to eliminate moisture/compresser oil? Also helps to use a new tip, and set the current low enough to drag the dip directly on the aluminum (say, 40-50A? slows the cut, but improves the edge).

Steve S

I've never had any luck plasma cutting aluminum. The edge always comes out very crappy.

I have used a Skil saw with a carbide tipped blade and a homemade saw guide to cut up to 1/2 thick aluminum plate. It works very well. If you have a table saw or access to one, a carbide tipped blade on that will cut plate, but be careful about kickback. There are saw blades specificly designed for cutting aluminum, they have a different rake angle on them than for wood, but any carbide tipped one will do, you just have to cut a little slower.

Other Steve

My problem is there aren't many straight lines on what I need to cut. The plasma cutter has good clean/dry air. I'm thinking about using my jigsaw...

This is what the cut looks like -

Otto Nobedder wrote:Cutting with compressed N2 will help, but grinding disks are probably cheaper!

Every little bit helps, though. Do you have a good dryer in line to eliminate moisture/compresser oil? Also helps to use a new tip, and set the current low enough to drag the dip directly on the aluminum (say, 40-50A? slows the cut, but improves the edge).

Steve S

Speaking of grinding discs, what have you found that works best on aluminum and aluminum dross?

Kevin

I'll have to look to be sure, but our disks are a German brand. "Schrupsheiben" or something like that. They make a grinding disk specifically for aluminum that works quite well, and doesn't load up. We get them from National Welding Supply.

That same aluminum disk is quite agressive on stainless, but goes away quickly with that use...

Steve S

That's pretty much how my plasma cuts on aluminum look. I just wind up sanding everything to a smooth surface.