Hi
Is it plans to build yourself or kits of machined or part machined castings?
In the UK there are regulations regarding the use of pressure vessels to enable compliance with insurance.
I do not know what the regs are in SA but you should check this out before starting as material choice for boilers needs to be compliant before you start.
I have built and run several steam set ups and will point you in the right direction.
Dave

hI there
is there anybody that can help me with plans for a steam engine and boiler for model boats
hawkgripen
s africahttp://www.stuartmodels.com/ try these good castings and good plans I built two of there engines one for missipI paddle steamer and the other for a tug boat