I'm busy making a small pulsejet engine and have rolled all the cones and tubes from 0.5mm steel sheet. The problem I now have is trying to weld this stuff. I've tried an arc welder with 1.6mm rod and 55amps (as low as it would go), but ended up burning big holes in everything. I have little experience with welding, but know that there must be a solution. I've thought about silver solder, but these engines glow red when running, so I've got a feeling that that may not work. The only equipment that I have available to me is an arc welder.