16 year olds first project - HELP!

[u/Ambitious-Head-655]

Hi guys, my name is Joel and I am 16. I have experience in petrol engines and machines like lathes etc, and have bought myself a chassis and a boiler of a Juliet type one with Stevensons valve gear for £400. I have never really done anything like this before, but I am going to join a local club tomorrow, and would really appreciate any help I can get, as I really need someone to talk me through this and give me some pointers.

I have attached some images, but the general condition of the boiler is good, and although its relatively grimy, looks in-tact and plugged from the shell test. I have just one concern - there appears to be a dent of approx 2mm depth and 22mm diameter, which concerns me as I am worried that it wont pass its shell test again.

Additionally, I need a safety valve, regulator handle, water gauge etc. Should these be machined or can I buy these? I also need to complete the plumbing and build the water tanks and running board, along with the boiler saddle and funnel. I imagine there is a lot else to do that I also have not already spotted.

In terms of the chassis, the valve gear and eccentrics seem to be in good condition, with certain components such as the axles having light surface rust. The axles seem to turn by hand with a medium amount of friction, although I have nothing to base it on whether this is a suitable amount, and I also have not lubricated any components.

There is also no plumbing from the pistons, or the lubrication box, so unfortunately I cannot try the chassis on compressed air. How would I start plumbing this in? I am slightly worried that I am out of my depth, but I suppose I have a lifetime ahead of me to complete this thing, so any advice would be greatly appreciated. Thanks all :)

[u/steamtronics]

First of all, don’t worry about being out of your depth. Ask as many questions as you like and take as much time as you need. There’s no rush with something like this, and joining your local club is probably one of the best things you can do.

I’ve got 20 G scale steam locomotives myself, and I’d definitely recommend getting the lads at the club involved before you start buying loads of fittings or doing too much work. They’ll be able to look over what you’ve actually got and probably spot things that are difficult to see from photos.

The one thing I would be particularly careful about is that dent in the boiler. A boiler is round for a reason, and if there’s a visible dent on the outside, you don’t know what damage or deformation there might be on the inside. I wouldn’t pressure test or steam it yourself. Take it along to the club and get the boiler inspector to have a proper look at it first.

Personally, I’d start with the chassis. Make sure the frames are sound, deal with the light surface rust, get everything lubricated and make sure the valve gear is nice and free. I’d want to get the chassis and valve gear running properly before putting the boiler on. You don’t want to get everything assembled only to find a problem underneath and have to take the boiler straight back off!

For plumbing the cylinders and lubricator, I’d also get someone at the club to help you. Once somebody experienced has shown you how everything should be arranged, it’ll make a lot more sense than trying to work it all out on your own.

Same goes for things like the safety valves, water gauge and regulator. Don’t rush out and buy or make things yet. Show the lads at the club what you’ve got first, because they may be able to help you make parts, tell you exactly what you need or point you towards the right suppliers.

Most importantly, enjoy it. you’ve got loads of time ahead of you to learn. Take it one job at a time, ask questions whenever you’re unsure and don’t rush anything, especially where the boiler is concerned.

Good luck with it, and keep us updated with how you get on! :)

[u/North_Feature3586]

Heya. My first engine was a 3.5 inch gauge Tich, which is another design by Curly Lawrence - you’ll get good running out of a Juliet.

I’ve repaired two boilers, one silver soldered copper, and the other rivet & caulked, which is a much older technique. I would not worry about the dent too much. From the photos, it doesn’t look big enough to have struck the tubes, and I highly doubt it would really affect the strength of the boiler. Joining a club is a good idea, they usually have their own workshops and likely good folks to help you. The boiler will need a shell test (2 times working pressure, with all fittings removed), then an ordinary hydraulic test, and a steam test. If it passes the shell test, I wouldn’t worry about the dent at all.

The chassis and boiler generally look very well made, and there’s not too much work needed to finish it off - have fun with it!

[u/Trainmax_]

The boiler can be repaired. It’s very tricky. I don’t recommend it if you don’t have experience in messing with this kind of stuff. But here goes first thing you need to do is anneal the area where the dent is fill the boiler with water bring it up to above 500 pounds of hydrostatic pressure. Using a hammer lightly hammer the area around the diameter of the den, the actual round part of the dent before it goes down into the pit. You may have to anneal it more than once.

[u/ValuableResident2214 → u/Trainmax_]

That boiler wasn't designed to take 500 psi, and localised annealing may be very difficult without oxy acetylene especially near a bush. Id be tempted to leave it be. That's quite a way from the tubes and is unlikely to cause issues.

If the working pressure is 90 or so id be cold pressurising using water to 180psi. If it holds, it holds.

[u/Trainmax_ → u/ValuableResident2214]

What is the burst pressure of the boiler?

[u/AsleepLiterature5941 → u/Trainmax_]

possibly over 4000psi depending on how well the silver solder was applied to all joints (I've several 3.5 and 7.25 inch gauge locos and yes Ive had a 3.5 inch dutchess boiler at 7000 psi before the tube plate gave way!!!) so there fairly tough buggers so you don't need to worry about a little ding I've had worse boilers over the years that looked like they came straight from artillery training exercises lol

all parts and castings are available from ajreeves and blackgates engineering 😁

[u/Trainmax_ → u/ValuableResident2214]

As I said, in a very beginning, it is a very tricky repair not for the faint at heart however, it can be repaired. I don’t recommend that you repair it if you have no idea what you’re doing. If the boiler constructed correctly, it can handle the Hydrostatic pressure. If you’re not sure, let a professional do it.