I have made a replacement boiler for a small static engine that belonged to my father . basicly it's a brass tube with 1.5 mm wall . with 2 end caps . will this need silver solder or would normal solder do ?
Contrary to what others would have you believe, ordinary tin/lead solder would suffice,
BUT it depends on the working pressure and the safety valve release pressure.
As an example, the makers of Meccano/Mamod used soft solder for their brass boilers but the relief pressures are fairly low at around 20-25 psi and the heating system is such that the fuel runs out before the boiler runs dry, secondary relief is provided by the face to face surfaces of the cylinder/port block....