water level glass

A very popular starting point for Live Steam. With their low cost comes a number of problems which can be discussed here
Abiogenesis
Cleaner
Cleaner
Posts: 31
Joined: Thu Aug 17, 2017 7:29 am
Location: Heights of High Wycombe

Re: water level glass

Post by Abiogenesis » Thu Aug 24, 2017 9:25 pm

Avalon,

Thanks for those two links. Why didn't I think of Ebay? Duh!

Yesterday afternoon I chatted with Roy Wood who suggested doing away with the water sight plastic by soldering a piece of brass over the slot. Not wishing to disturb the two soldered bolts that secure the brass backhead, I cut a piece of tinned steel from a dog food can, the same size as the original water sight plastic & placed it on the gasket "O" ring before inserting the plastic. I bolted it up & tested the boiler on the gas stove. No leaks & completely reversible when I try polycarbonate.

Today was a good day for steaming.

Abiogenesis
Cleaner
Cleaner
Posts: 31
Joined: Thu Aug 17, 2017 7:29 am
Location: Heights of High Wycombe

Re: water level glass

Post by Abiogenesis » Thu Sep 21, 2017 11:11 pm

It's been a while & I finally solved the water sight glass problem for my Mamod SL1, currently in the ownership of the Chiltern Heights Railway as Loco No 1. After a fourth boiler explosion resulting in the loss of the brass steam dome, due to my efforts with soft solder not being up to the task, I bit the bullet & took delivery of a silver soldered "Janet" boiler from Roy Wood. Loco No 1 is Mamod in name only, as only the frames, drag beam, smoke box & reverse valve remain of the original SL1. The cab has been cut away & the side tanks have been manipulated & now contain substantial loads of lead ballast. With consummate ease, it hauls Loco No 2, dead in tow, together with all 7 of my Mamod wagons, loaded to weigh 4 kilos on 14 axles; 5.5 kilos in total. I shall be adding an inertia wagon to the consist, as I am being out paced on the downgrades. :(

I now have a 100mm x 100mm business sample of 2mm thick polycarbonate. It has a glass transition temperature of about 147 °C, so it softens gradually above this point and flows above about 155 °C. The temperature of steam at 40.3 psi is 141.7 °C. The glass transition temperature of commercial grades of acrylic glass (aka Perspex) range from 85 °C to 165 °C. On paper at least, polycarbonate should work. I'm loath to strip Loco No 2, as it's coping well with its 40psi SV & runs with panache. When the time comes, I'll fit a polycarbonate window.

User avatar
Boustrophedon
Trainee Fireman
Trainee Fireman
Posts: 235
Joined: Wed May 22, 2013 7:43 pm

Re: water level glass

Post by Boustrophedon » Wed Jun 10, 2020 12:00 am

When I tried polycarbonate it failed very quickly developing lots of bubbles inside the plastic. It may have been a different grade though.

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests