Copper Boiller

[IronMan]

Hello,

While I was looking further on in the book mainly at the boiler for 1.5" scale. Looking for what size of material to keep my eyes out for.I noticed that most of the upscale boiler is 1/8" copper except for the backhead and the front tube sheet which is supposed to be 5/32 " Now I have been looking for 5/32 " and can not seem to find anything resembling that, it goes from 1/8 to 3/16 I wonder if Kozo used metric and then converted to approximation in standard ? Anyone at the boiller making stage, or passed that ?
By my calculations he was using 2mm and 3mm copper sheets, I dont think I can get 3mm sheets up here in Canada even though thing are suppossed to be metric. I quess I will have to do some more research on the subject. Perhaps someone has suggestions?

Regards,
IronMan ;D

[IronMan]

Hello again,

I did not have enough time this morning to finish what I wanted to say. I noticed that in the 3/4" scale the boiller thickness remains the same at .079 or 2mm. Is there any boiller standards? for thickness ? I suppose using 3/16 would only add weight, but would using 1/8 compromise the intergrity of the boiller? I also imagine that copper sheets in MM are obtainable from Overseas but the cost of shipping would outweight the cost of the thicker 3/16 available here on this continent. I leave you with these thoughts while I go and do some draughting of the boiler parts to see what I need to get.

Cheers
IronMan

[Bill Holland]

In nelsons book, "So you want to build a live steam Locomotive", he lists some forumulas for figuring out thickness of sheet to use in a boiler. With a pressure vessel, you want to maintain a safety factor of 6 atleast, that is, if your boiler is designed to operate at 100psi, TECHnically, it could withstand 600 psi.
Using the forumulas, you could figure out what thickness to use. Generally, with 1.5" scale, people use Steel boilers, but dont have to. I Think this is because a boiler that big requires too much heat to silver solder from a standard propane torch? Steel boilers are welded not silver soldered.