These pressure tanks are an exact copy of the original 1910 Stanley tanks except for the material. The original early pressure tanks were drawn from brass. Later tanks (during the condensing car era) were steel. Brass is prone to stress cracking and many original brass tanks have cracked. The later steel tanks tend to rust out.
These new tanks are hydro-formed from 14-gauge copper. Copper is much less likely to crack than brass and will not rust out, so is a much better material choice for this application. The 14 gauge material thickness is the same as the originals and the end fittings are a full 1-3/4” diameter inside, just like the originals.
The halves of the tank are soldered together with a 7/8” lap seam as original, but with silver bearing solder (96% tin, 4% silver) which is over 3 times stronger (14,000 psi tensile strength) than the best tin/lead solder (63% tin, 37% lead). These tanks are sanded on the lathe beginning with 120-grit aluminum oxide, then with a finer paper to clean off excess solder and flux stains. Hydro-Tested with kerosene to 400 psi. Ready for painting or final polishing.
Don’t fool around with dangerous 80-year old original brass tanks which can split at any time and spray fuel out at over 120 psi!