The problem with buying a commercial boiler is you have to rely on the person butting it together to use the proper materials and methods. I have seen some commercial boilers that I would not want to be around when they are operating, and others that I would be proud to own and operate (Maccsteam is defiantly in that group).
The problem with a homemade boiler is that you have to rely on the person butting it together to use the proper materials and methods. Again I have seen some that I ran the other way when they were going to fire it up. There have been a number of boilers that I have been asked to give my opinion on that I have said cut it in half with the band saw and them I will show you what I think is wrong with it. Then there are some that you look at and say lets find the boiler inspector and get it under steam.
Gerald.