Thanks for the comments and tips JJ. I sometimes use a process I saw on the internet. Solder is hammered flat to the point where it is paper thin. Small bits can then be cut with an Xacto knife and either inserted between the fluxed parts before soldering or positioned right along side the joint. I'm applying flux with a hypo; the paste keeps the solder bits in place (usually). I also use the tin both joints first method. I like the paper thin piece between parts when using the resistance solderer. That's what I'll try when the time comes to attach the walkway brackets.
A concern is whether I can generate enough heat to sweat the tank ends and domes to the shell. I am still contemplating whether I can use my oxy-acetylene torch for the job. I've got a small torch and need to see if I can get a soft enough flame so as to not end up with a banana shaped tank. Other methods first - to be safe.
