I've had a Diversion 165 TIG for a few years now and I've used it a couple of times to fix an aluminum ladder or a small part in SS where heat would have been an issue. Otherwise I almost always use my Millermatic 185 MIG welder for fabrication.

Recently I bought a new Travel Trailer Toy Hauler and I needed to fabricate an aluminum battery box for a pair of Solar Charged batteries. The project came out great and the Diversion couldn't have worked better. Very impressed.

You can read all about it here:

I experimented on a few scrap pieces of the diamond plate aluminum as I very rarely weld aluminum. At first it was a disaster. Burn through, not enough heat....terrible. I finally remembered a video on "Welding Tips and Tricks" about using angle iron as a back plate on the joints and turning up the heat and using the foot pedal properly and the welds started to look excellent. The angle iron acts as a heat sink and it contains the argon behind the weld.

Thanks for looking

BTW...Lots of other projects on my wen site and especially in the photo album