Hello, all,
I got myself roped into a project making up frames for panels to protect stained glass windows when a church sanctuary is used for a gym during the school week. We went and got $800 worth of 6063 rectangular extrusion from the metal yard, and I'm having an incredibly tough time TIG welding this stuff. I don't have a lot of material to spare while fooling around, either, we bought them out of an odd size, 1 x 1 7/8 x 1/8" wall. (That's 1 x 1.875" outside dimension.)
I just got in some 3/32 Zirconiated tungstens, a gas lens set for that size, and some 3/64" 5356 MIG wire for filler. I got a pretty good fit-up of the edges after a whole bunch of fooling around with my 4x6 hor-vert bandsaw. I tried to weld this with without grinding a vee to fill, maybe that is part of the problem, although my TIG book suggests that is possible up to 1/8". I have a Lincoln Square-Wave TIG 300 that as far as I know is working perfectly. I have a Weld-Craft water-cooled torch with a Miller cooler. I know that MIG wire is not the perfect thing for TIG, but I'm not even sure I need filler wire.
Does anyone have any advice on what to do, common newbie pitfalls, etc? Obviously I can't support the back of the weld inside the tube. I think preheat is going to be needed, I have a Bernzomatic propane torch and an Oxy-Propylene set (essentially generic Oxy-MAPP) but have no idea how much pre-heat to use. I did try welding a couple pieces of tiny scrap, and that went a LITTLE better, I did actually get fusion along part of the seam. That sort of supports the idea it needs preheat. I KNOW I'm in way over my head, here.
Thanks,
Jon