Building the 2.5" Scale Shay

[Soot n' Cinders]

Thanks for the tips guys! I’ve got some more research to do.

[rkcarguy]

I wouldn't be against using aluminum either, but again, the tarriffs have hit that and the last quote I got was over $4 a pound, so the SS is probably the best deal right now. As far as fiberglass coated steel, it seems like eventually the two end up delaminating and the steel rusts. This could be 20 years down the road before it does, but it will. The stainless will last a lifetime.

[Soot n' Cinders]

Well, I think we have a final direction on material. Stainless sounds nice but its expensive, and I have a friend with a 2-8-0 built in the 80's that still has the original galvanized tank and the tank doesnt show any big signs of deterioration other than just build up of junk over the last 30+ years since the tank does not have a drain without a filter. So I think with good care, a galvanized tank will be more than acceptable for my purposes. Now just to acquire material, which Im leaning towards 18ga right now with copper rivet construction and soft solder sealing.

Along with all the research and decisions involved in the tank, Ive made more progress adjusting the injector plumbing. Both injectors are now operated with push-pull valves made from PM Research straight globe valves with the threads machined off of the stem. I may make some little levers to actuate them later but for now the regular valve hand wheels will work. With the switch to straight valves from angles, I had to replumb the steam line with an arched tube. This also allowed me to move the injectors into a position that looks better and should work better. Now just to figure out the overflow lines and the water lines.

[rkcarguy]

Are you planning on having the tank hot dip galvanized? Pre-galvanized sheet won't solder, and puts off a poisonous yellow smoke when heated.
If you are hot dipping, the massive temperature change can make the sheet metal "plump" in the frame as it heats up much faster than the corners and frame members. For example, my workplace makes a custom railing from time to time with various sheet metal panels for infill. The panels have to be assembled AFTER galvanizing, otherwise the sheet metal goes crazy and gets all lumpy and warped as it doesn't have anywhere to go being welded into the U-edging frames. Hot dip runs about 800*F, so no solder is going to survive that. I'm curious how you intend to put this together.

[Soot n' Cinders]

Are you planning on having the tank hot dip galvanized? Pre-galvanized sheet won't solder, and puts off a poisonous yellow smoke when heated.
If you are hot dipping, the massive temperature change can make the sheet metal "plump" in the frame as it heats up much faster than the corners and frame members. For example, my workplace makes a custom railing from time to time with various sheet metal panels for infill. The panels have to be assembled AFTER galvanizing, otherwise the sheet metal goes crazy and gets all lumpy and warped as it doesn't have anywhere to go being welded into the U-edging frames. Hot dip runs about 800*F, so no solder is going to survive that. I'm curious how you intend to put this together.

I’m not going to have it hot dipped, there’s a place not far that could do it but I have no idea of the cost and my understanding is galvanized sheet is solderable. What I’ve heard is a little scrub with a scotch brite pad and using some acid based solder makes it easy to wet galvanized steel with regular plumbing solder. And I didn’t think the temps for plumbers solder weren’t high enough to cause issues with the zinc burning off. I’ll run some tests out side though and see what happens in case something weird does happen.
The primary structure will be from copper rivets and the solder will be the sealant.

[rkcarguy]

Ok, I hope that works. Definitely test it on some scrap before committing. I thought around 400-450*F the zinc started to go, but I'm not absolutely sure. I know I got sick welding and grinding on zinc at one point.
Have you looked into aluminum? I know it's expensive right now but it might be worth it for it's ease in working with it and its not going to corrode as long as you aren't around salt water. Despite it being a higher price per #, it's also far lighter so the sheet price may not be that much more than steel at the end of the day. My aluminum lake boat is 40 years old now and the metal is still in great shape, it's even seen some salt water use. It's riveted and has some sort of sealer in the seams.

[Soot n' Cinders]

I have not really looked into aluminum. I don’t think I’ve ever seen an aluminum tank in the hobby, not really sure why. Aluminum seems like it’d have to be babied so it didn’t get dented up from use since it’s so soft. Ease of working is a double edged sword, especially with me sitting on top of the tank.

[rkcarguy]

Where one would use 18ga steel you'd probably want to use .080" aluminum for equal strength. 5000 series has decent strength, it's all about the shape and structure underneath though when dealing with any sheet metals. With a good epoxy primer and paint I think it would be pretty tough.

Btw, you have the post of the forum here, just ticked over 100,000 views!

[Soot n' Cinders]

So its been a while since Ive posted anything here... I've been busily working away on the water tank for the shay. I settled on using 18ga galvanized steel for the tank and then sealing it with plumbers solder. This seemed the most cost effective route with a proven service life from other locomotives, one of which is going one 30 years with its original galvanized tank.
The tank is built up from seven separate sheets with the sides being curved. The top and bottom sheets will be attached to angle iron I made from 1in wide strips of the galvanized steel that were then beat into a 90 degree angle using a bench vise and a 3 pound hammer. The bottom will be completely riveted on and sealed with solder, the top will be held down with 12 #2-56 screws and sealed, if needed, with silicone sealant. The tank bottom also has 3 large holes for connecting with the water supply lines for the injectors and one that will be a pass through for the delivery standpipe from the steam siphon.

tank bottom

first test fit

coal bunker

second test fit

[Brian Hilgert]

Looking good! how did you do the curve sections? just bent it around a piece of pipe?

[Soot n' Cinders]

Looking good! how did you do the curve sections? just bent it around a piece of pipe?

Yep! I clamped the sheet between a piece of angle iron and a pipe a little smaller than the desired diameter, and then I used a crescent wrench to roll the pipe and sheet against the bench till its roughly the bend I want. And I over bend a little too so the metal is easier to work with since I can more easily unbend it rather than try to bend it on that radius a little more

[Brian Hilgert]

Very nice. Thank you!
One more question, Where did you purchase your wood for the running boards? I cant find any sources that will offer 6+ feet for the fireman's side.

Thanks,
B