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Its Ok for very small boilers that won't be running at high pressures say below 30psi and not getting a lot of use. Most of the "toy" steam models like Mamod have used brass boilers for years.J
George does the same not apply to copper? making one from unknown scrap material could be just as risky and I'm sure most UK inspectors would not want to test something made by re rolling an old hot water cylinder or roofing sheet such like.Same would apply if you used anyold steel to make a boiler and the welds were not approved
Also don't have to be a coded welder for steel, you can just submit the welds for NDT at a cost of £50-60, show the welds have been designed correctly and if they pass you are OK.
But would you test one if the brass was from a known source with paperwork to prove it and to the right spec? And would you know if that seconhand copper was C106 or something else that could have suffered embrittlement during construction?Also don't have to be a coded welder for steel, you can just submit the welds for NDT at a cost of £50-60, show the welds have been designed correctly and if they pass you are OK.Should also say that as the OP is in the US he should go buy his state boiler code and not what applies to clubs in the UK. Basically use materials that are allowed by the code and to the required specification, do the calculations to get correct thickness, joints, stays etc and consult with whoever will be testing the boiler if going to be used in public.Seems SMEE are happy with brass Poly boilers http://www.modelenginemaker.com/index.php/topic,5690.msg110959.html#msg110959