I enjoyed building a three truck Shay based on castings from Ken Schroeder with some help from Koxo Hiraoke. I run it at the track that the Orange County Model Engineer's have in Costa Mesa, CA.
Grinding steel on diamond disks can ruin the disks. Yes, diamonds are the hardest thing but when grinding steel the carbon in the hot diamonds can migrate to the steel and cause many problems which why you should only grind carbide on diamond wheels.
I have made two of the copper boilers from P M Research and you can find them on the web. The make very complete steam engine and boiler kits and their catalog is worth having for itself. They also offer a line of fittings and castings that I have used and employed on my projects including a...
This is a 1:8 scale three truck Shay and it is propane fired. It runs on 7 1/2" track and because of the covid I have not been able to run it yet at the Orange County Model Engineers track.
I have used Alum twice for broken taps in brass and it did dissolve the taps. You can tell you are getting a chemical reaction because there is a stream of tiny bubbles coming from the hole. It just takes time. You might have to coat aluminium with something to protect it but the alum does...