Materials that we want to launch out of the tube.
Salts :Strontium Chloride: :Boric Acid :Sodium Chloride :Lithium Chloride :Copper Chloride :Copper Acetate :Potasium Chloride :Calcium Chloride
Powders :Magnesium :Carbon Powder :Titainium Powder
Fuels: :Methonol :Ethonol :Gasolina
The problems that we may have with this is that many of these materials are corrosive. Oddly enough CPVC plastic can deal with all of these with no problema. Problem is I dislike the idea of making the launch tube out of plasitca.
Materials to be considered.
Chrome Plated Brass
Steel: The problem with steel is that the alkali matal salts will seriously corrode it. Still this is unlikely to happen as a very fast rate.
Stainless Steel: On the surface this seems to be the best. However it can't handle Copper Chloride and one gets the suspicion that other salts may cause pin point corrosion. Still it is a pretty good choice.
Nickel: Nickel or nickel plated steel is possibly a good choice. The launch tube could be constructed of butt welded steel fittings, then nickel plated to improve corrosion resistance. A plus is that it'd look really cool. It could then be laquered for extra corrosion resistance.
Hastalloy-C: Same as above. Hastelloy-C is a high nickel content steel.
Copper: Just a throught, copper might actually be good for this application. The copper tubing could be brazed and then nickel plated.
Chrome Plated Brass: Might be good especially for small fittings.