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
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Chris Cairns
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Re: water level glass

Post by Chris Cairns » Sun Aug 13, 2017 8:06 am

avalon wrote:So if we can't use that what do you recommend?
The right water to use is a controversial subject online.

Roundhouse have a good technical section on their website, which includes their views on water - http://www.roundhouse-eng.com/tech.htm#water

Accucraft say to use filtered rain water or distilled water.

Regner say to use distilled water but to add 5% tap water - they use brass boilers.

Our tap water here in South Lanarkshire is soft (30 PPM) so I just use that. I treat all my locos as if they are fitted with a brass boiler & drain the water out if they are not going to be run again for awhile.

Chris Cairns

Abiogenesis
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Re: water level glass

Post by Abiogenesis » Tue Aug 22, 2017 7:42 pm

Hello.
This is my first post here. At the end of May this year, I started to watch many videos on YouTube about garden railways & thought of having some kind of a layout myself. After watching Roly Williams fire up his Hornby G100 “Rocket”, I persuaded my eldest son to relinquish his 34 year old G100 (bought when he was born) from its pride of place on his sideboard. I was prompted to resurrect my Mamod ST1 as well, which I had purchased from Hamleys in 1962, as a 20th birthday present to myself.

Some years ago, I replaced the G 100’s original gas tank & at the same time I also lagged the boiler with Rockwool, but didn’t run it & it became only a display item. I placed it on chocks & fired it up three times & discovered that the burner on WOT did not generate enough heat to produce the results I saw in Roly’s video. I disassembled the gas line & fittings & they were all clear. I was left with the burner & so, purchased a preowned spare from Tony Green. Before its arrival, I erroneously concluded that the boiler had a leak, because further dismantling revealed that the glass fibre insulation was wet. Prudence dictated that I should seek professional advice, so I sent the boiler to Western Steam for examination. Geoff tested it hydraulically to 100 psi & it will be back soon, fitted with their 40 psi safety valve.

Meanwhile, I turned to Ebay & successfully bid for an SL1 with only one cylinder. It came with an oval of Mamod track & a Mamod open coal wagon. I was delighted. Having already completed some research, I concluded that Roy Wood Models had the upgrades I desired, so a pair of his upgraded cylinders with “O” ring fitted pistons were ordered, together with steam turret, needle valve regulator, displacement lubricator with drain, water top-up valve, a 40 psi safety valve & a number of decorative embellishments. Here I must praise Roy Wood for his valuable & constant help, whilst I struggled to climb the learning curve of Mamodification.

The plastic sight glass ruptured & led me to reducing the loco to only its running chassis, whilst I figured a way to replace the drilled out rivets on the boiler. Copper wire enabled me to position two bolts, but how to seal them? I salvaged a piece of Rubbaseal roofing from the skip (my youngest son is a bricklayer & is building himself a loft conversion in our roof space) & cut small washers to place on each side of bolt, where it passed through the boiler. This enabled me to secure the brass backhead in place. It worked very well.

About six days ago, loss of steam pressure led me to suspect that the sight glass had failed again. I had to remove gas tank & ceramic burner, the displacement lubricator & reposition the regulator, before I could gain access. I then realised that the sight glass had not leaked, nor had the Rubbaseal washers given way. It was the work of only about fifteen minutes before I had the loco in steam again. It was the steam dome insert that was the culprit. Back when I had the boiler out of the chassis & had substituted the RWM regulator & steam pipe for the Mamod original, I had also cut off & soldered the steam pipe where it exited the bottom of the boiler & had plugged the pipe with solder beneath the steam dome fitting, but I had not noticed that the insert was loose. I used a gas fired torch to effect a permanent repair, then sprayed the SL1 with heat resistant, red brake caliper paint.

I should also mention that a few days ago, a Mamod trainset with a guards van, a log carrier & an open coal wagon appeared on Ebay. Again, I was fortunate. Another gas burner from Forest Classics was fitted to Loco No 2 & I have a set of similar motive power upgrades for it on order from RWM. More rails & two sets of points have also been purchased & attempts to run two trains at once, have resulted in moments of high drama & downright panic.

This morning, I fitted the RWM cylinders to Loco No 1 again, after first deciding to solder the bolts that secure the brass backhead. I also soldered the steam dome fitting to the boiler, because of the constant leaks. It does not take long to reassemble Loco No 1 because I have cut down the cab. The safety valve lifted within 5 minutes & with three wagons heavily loaded with shingle & timber, plus a guard’s van with 1lb of lead sheet on the floor, Loco No 1 raced away with three full turns on the regulator. It got to the curve before I did & derailed disgracefully. I then attached Loco No 2 dead in tow & the added weight made little difference. Is it possible for an SL1 to be too powerful for its own good? After a few 50 feet circuits the loco stopped abruptly & would move in neither direction when pushed. An inspection revealed that the hind pair of wheels had shifted on their axle. Judicious work with pliers rectified the problem & I levered the triangular tabs with a steel punch to tighten the wheels.

Continuing to blow off, the loco hauled its load for more uncounted circuits & I failed to take account of the increased steam consumption. The train halted & it was the smell of burning paint that alerted me; that & the ruptured water sight plastic. AArrrggghh! No useable spares! What to do?

Tesco sell boxes of 100 white interdental sticks (toothpicks), labelled Pro Formula. These boxes are semi-transparent & very tough. I cut out two strips & shaped them & tried them both at the same time under the brass backhead. Too thick. Swapping “O” rings enable me to try one piece of plastic & it did not leak at 40 psi hydraulic pressure. Placing the boiler on the gas stove, the safety valve soon lifted. I viewed the plastic sight glass from afar with binoculars. No leaks. After four minutes, I turned off the gas & let the boiler cool. I have just removed the backhead & inspected the plastic. There is the very slightest impression of the rectangular slot on the surface of the plastic, but it’s considerable less that the imprint on the Mamod items. I could only just see it with my forger’s headset. Those are my findings. Make of them what you will. I’ve no idea what type of plastic was used in China to manufacture these boxes. It’s tough as old boots. I'll send samples to those who would like to repeat the experiment.

Regards,

Perry

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Re: water level glass

Post by Abiogenesis » Wed Aug 23, 2017 10:25 am

Belay that idea about the substitute water sight glass. It failed on this morning's first run. It's not as thick as the Mamod item, which seems to be 2mm thick. There was discussion in this thread about the merits of solid polycarbonate sheet. Google found me a supplier for a single sheet of 2mm x 50mm x 50mm for £0.75, but they want a low order fee of £13-50,bringing the price with VAT to £18. :lol:

It's like reinventing the wheel.

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Re: water level glass

Post by avalon » Wed Aug 23, 2017 5:28 pm

Don't do it!

Go to www.tamstar.co.uk and order a 'sample'
100 x 100mm 2mm A £0.99 delivered.
It works !

Vic

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Re: water level glass

Post by avalon » Wed Aug 23, 2017 5:57 pm

It might be easier to go to
http://www.ebay.co.uk/itm/CLEAR-PLASTIC ... o2vl1b6saw
I hope this connects but I'm not too good at internet stuff!

Regards

Vic

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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.

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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.

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Boustrophedon
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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.

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