Making a Stunt Tank

Your diagram shows brass shim stock. In my opinion, that would be a very poor choice of material to use. I wouldn't use brass tubing either. Brass and our fuel don't get along well and the green death will overcome. Brass work hardens and splits. Brass shim stock is strained one direction and will inherently split if bent improperly. Brass tubing isn't seamless and once again it will split. Copper tubing is not as prone to this problem. If you use clean tinplate, like the type that's found on a laquer thinner can, it will work far superior. In addition to that, I wouldn't sand tinplate with abrasives prior to soldering. Using a wire wheel or Scotch-Brite pads yield far better results and will also prevent the plating from being removed. The plating is your only defense in preventing corrosion which will readily happen unless you remove all of the flux. I do this with a laquer thinner followed by a soaking of high percentage castor fuel for at least 24 hours. I like to use 60/40 rosin core and Nokorode paste flux. Be certain to solder the pickup at the rear of the tank or it will act like a tuning fork inside and will once again fail. If possible, solder your filler pipes inside as well. When complete pressure test after cleaning all the flux off of the exterior of the tank and try and fill it up with a syringe like your trying to pop it. Ken