I am working on a miniature pulsejet design, and have several problems due, in one way or another, to the small size of the combustion chamber (approx .75 in. diam x 2.0 in. long). The exit nozzle (approx .75 in. diam down to .375 in. diam) is rather short (about .5 in.) but as smooth as I can...
I have had good success welding stainless with oxy-acetylene technique using high temperature flux all around the weld site, but the flux around the weld remains as a tight black fluoride "glass" coating that is unsightly and a real bear to remove with such techniques as wire brushing...
