I'm building a cnc machine and I just bought a whole bunch of steel vat a surplus store. I need to braze or weld them together, but I can't braze since the objects too big for my propane tank, it disipates tthe heat to fast. I can't afford an arc welder. What should I do? I don't want to use nuts and bolts because that adds wiggle to the machine and I lose all of my accuracy.