Crofter, good info, bad for my design. I will probably have to pre heat the SS and copper fittings on my set up. I do have one idea that I hope will eliminate any travel through pipes yet still use the box on top design. sort of you ideas of a hole in the side of the pipe rather than the end. Only my hole will be in an aluminum rod large enough for a closed end hole and the hot part of the glow plug directly below it. It will have to slide like a drawer through the wall of the box just far enough to be able to add the next dose of acid to the pocket then slide back in to be heated.