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Join Date: Jul 2006
Location: Louisville, Co
Bikes: Arcalis Andorra 01 custom build, Specialized Stumpy
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For lugless, you can go two ways, either TIG (Tungsten Inert Gas) welding or fillet (brass bead) brazing. Since you've never done it before...my first reaction is to say go with a fillet braze. It tends to have the least amount of investment in equipment and it's a bit harder to make an irreversible mistake. TIG welding requires that you have, well a TIG welder for starters, and a good used one will run you around $1500 for starters. Then you would need a tank of Argon gas, gloves, face shield, welding wire. Also, you would need quite a bit of practice playing with the amperage level that is right for your tubings wall thickness, not to mention a bit of practice with technique.
Fillet brazing on the other hand is not as much of a chore to learn and get good at, and you have more room for error and fixing a screw up. Equipment can be had for pretty cheap, all you'll really need to buy is an oxy-acetyline torch with a size zero or "1" tip, about 20 feet of hose and a regulator for each of the tanks. The nice thing is that I can't tell you how many times I've seen oxy-acetyline set-ups in a pawn shop for cheap, you just need to look around. The gas cylinders can be rented, and you would not need to get enormous sizes. Other peripheral materials would be brass-bronze brazing rods (I preferred to use 1/16" rods when I built, but some builders prefer 1/8"), brass flux, applicator brushes, brazing goggles and a good dremel to finish your brass beads. Brass brazing is also easier to learn in my opinion and makes for a very strong frame. Brass tends to have excellent torsional strength and is very suitable for brazing frames. Plus, if you really screw a joint, you can almost always pull the tubes apart, clean them up and start over. Although, I don't recommend this officially, heating and cooling will change the structual properties of the steel, making it more "brittle".
There are tons of books and reference material available for either one of these techniques, so do some research and make sure that with whichever method you choose, put some practice in on some scraps to see how your technique works.