My diesel tankage amounts to only 15 gallons and I want to carry extra when cruising open water or debarking for places like Europe and the Islands. I acquired several 5 gallon jerry cans that are plastic. An aquaintance with diesel experience says that the plastic cans break down inside and contaminate the fuel and cause problems with the filters and engines. I really need to know if in fact it is not wise to store fuel in these containers. The other consideration is propane. I want to save myself huge money by sailing with regular steel propane tanks that I have treated with rust and corrosion inhibitors and coated with 'Rustoleum' paint. Since the valves and fittings are brass is this the acceptable arraingment that I hope it is? The aluminum and stainless tanks are very cost prohibitive, but if I must - I must. Thanks in advance for any insight on this.