Hydro Testing

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Bill Shields
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Re: Hydro Testing

Postby Bill Shields » Sun Aug 20, 2017 3:23 pm

Good luck getting anything official from Little Engines for something built during that time and of that scale.

the 100 psi design from the old catalog is probably a good place to start, however at the time they were not aware of the problems with the cast sheets.

Another thing to be concerned with is the fact that during that time period, many of these boilers were put together with SIL-PHOS or PHOS-COPPER solder, which reacts badly with sulphur in the coal -> and becomes very porous after time.

I have a copper boiler supplied by another manufacturer, built in the 1980s, that is put together with Sil Phos, so the technique was still in use 40 years ago.

I am not aware of any catastrophic failures from this solder, but when it begins to fail (leaks like a garden sprinkler), there is no fixing it.

80 PSI is actually more than enough considering the slippery nature of the beast, but in reality if it passes a 125 PSI hydro without a lot of weeps, you should be good to go.

jscarmozza
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Re: Hydro Testing

Postby jscarmozza » Sun Aug 20, 2017 6:04 pm

James, Bill, thank you for all of the advice and information...lots to consider and digest. It's kind of ironic, but I thought the fact that LE built the boiler was a big positive and a big reason why I ought this engine. I'm disappointed that the boiler isn't as 'good' as I thought it was, but the engine is a beauty and the workmanship excellent, I'm still in love with it.

Thanks again, John

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Re: Hydro Testing

Postby jscarmozza » Sun Aug 20, 2017 6:44 pm

Bill, if the boiler proves to be sound, do you think charcoal would be the better fuel to use? I make my own charcoal for certain forge work that I do, it burns clean, hot and fast, but most important, no sulphur. John

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Fender
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Re: Hydro Testing

Postby Fender » Sun Aug 20, 2017 7:01 pm

The sil-fos solder is still used for brazing joints in refrigeration work, where there are no problems. It's the exposure to combustion gases from coal where the problems begin. By contrast, joints that are silver-soldered are usually ok in a coal-fired boiler.
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James Powell
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Re: Hydro Testing

Postby James Powell » Sun Aug 20, 2017 8:42 pm

It is the sulphur in the coal that is the problem. If it was coal fired, and is sil-phos built, then it likely will leak like Bill said- kind of like a water fountain. No fix for it, but making a new boiler. Same thing if the bronze (?) alloy that LE used for the castings has lost (most likely zinc), in that it is likely going to turn porous and prevent a sucessful hydro or firing of the boiler.

Generally, a commercially assembled boiler is going to be safe, while it may not be workable as a boiler. A home done one might (again, speculative here) not be safe due to flaws in construction that the builder didn't know better about. That being said, there have been commercially supplied boilers which have had serious design flaws contained within them...but someone else has at least, likely, looked to see if there are problems.

The Sil-Phos problem is not new, we ran into it in the mid 80's, and the workaround is easy enough- convert to propane fired. (I hear the boos from here...). Burning charcoal is another possiblity, but you are going to burn 30-50 lb/day of charcoal in a 1" model. If you make it yourself, that should be fine, but otherwise, it gets expensive in comparison to coal. Once the sulfur has done its damage, it is too late, and that is that for the boiler. Fortunately, with a railway engine, it is usually possible to replace the boiler without as much crying as a traction engine...but it is still not a small job.

Bill may well be right about running at 80 lb, generally in a reasonably well designed/built model, much above 40 psi is recovery room rather than useable force. However, that recovery room can be nice to have ! My Britannia had been running at 60 psi blowing off, which is a bit low (designed for 80). At 80 PSI, it runs like a skittish cat, very easy to spin the wheels. So, in some ways, it is easier to unscrew the safety valves and run at 60 psi than leave it at 80 psi. I think dad wound the springs back to 80 PSI, because he was using it as his heavy engine for passenger pulling. (well, OK, his intermediate engine...heavier than most of his household 3.5" gauge engines, but lighter than the Wren in 5"...and in 3.5", which GHLS has, along with 4.75"...). If he'd fix it and then I could take it back... :)

James

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Re: Hydro Testing

Postby jscarmozza » Fri Aug 25, 2017 3:54 pm

I did the hydro test today, now I know what jlakes85 meant when he started this thread. I followed Bill's advice, pumped it up to 50 psi very slowly, the whistle, some valve packing and the throttle packing started to drip, I tightened them a little and inspected the boiler for leaks or weeps; I checked inside the firebox and smoke box and all around the boiler, no signs of moisture. Over this time period the gauge pressure dropped to 30 psi, I then slowly pumped it up to 80 psi, the checks in the axle pump began to leak back through the return pipe, and the valve cylinder packing began to drip, I didn't tighten anything and slowly took it up to 125 psi, by this time manual boiler blow-off valves were dripping at a rate of about one drop every 5 seconds, axle pump, valve cylinders and whistle at a drop per second, I again checked the boiler all over for any signs of moisture and found none. I kept the pressure between 120-130 psi for about 5 min by constantly adding water then ended the test and inspected the boiler again for any signs of leakage and found none. There was pressure on the boiler, low sometimes but pressure nonetheless, for almost 2 hours and the boiler seemed sound...everything leaked but the boiler, but isn't that what steam engines do? I have to assume that when everything heats up a lot of the leaks will stop or slow down considerably. If I tightened up the packing on everything that leaked, I don't think the engine would run. After I finished the test and drained the boiler I was blowing out the residual water and decided to run it a little on air to get some oil into the cylinders...the throttle was so tight I had trouble fine tuning the speed, and that was with about a half turn on the packing nuts! Hydro test....absolutely important....but on a fully functional in service engine ther has to be some consideration for leaks....because they're all over!

On the matter of running the engine at 80 psi instead of 100 psi, I screwed the relief valve into the gauge tee and pumped it up to 100 psi, than backed off the spring and let it leak down to 80 psi and hold....is that how it's done?

Thanks for all of the advice guys, John

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Bill Shields
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Re: Hydro Testing

Postby Bill Shields » Fri Aug 25, 2017 4:10 pm

yes...that is how it is done....

welcome to the world of leaky steam.

getting a hydro that doesn't dribble requires that you completely plug off EVERYTHING to the outside world (and pray!)

Perhaps the throttle packing has gotten old, and dry and should be replaced with something smooth and pliable. I am partial to solid graphite ribbon, others like PTFE...they all work..but old stuff that has gotten hard and brittle won't seal worth a hoot unless really jammed up tight.

leaks through throttles, safeties, turret valves, etc are a way of life.

some fix themselves as they get hot...some get worse..

in some ways they are a bit like 2 stroke motorcycle engines...running partly on scientific principle and part on black magic.

as long as you don't get water where you don't want water...joints, tubes, mud-ring...superheater...then you are good to go.

Can you take a close up picture of one of the silver solder joints = around a stay or the fire door or whatever.

would like to see what type of solder was used.

Will explain when there is something to see.

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Re: Hydro Testing

Postby jscarmozza » Fri Aug 25, 2017 6:30 pm

Bill, I hope these photos are what you are looking for, John
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Bill Shields
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Re: Hydro Testing

Postby Bill Shields » Sat Aug 26, 2017 9:25 am

can you sand / scrape / brush an area of a silver solder joint and retake the middle picture area -> maybe with a bit more light?

trying to determine what it is soldered with....

the middle shot is OK, but too dark to see the detail of interest.

jscarmozza
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Re: Hydro Testing

Postby jscarmozza » Sat Aug 26, 2017 11:41 am

Bill, I buffed it with a wire wheel and took it outside in the sun light, hope you can see the details, John
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Bill Shields
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Re: Hydro Testing

Postby Bill Shields » Sun Aug 27, 2017 11:21 am

that is what I want and to me => it looks like it was done with Sil-Phos solder

Build up of that type is difficult with other types of silver.

Were it me, if you WANT TO KEEP that boiler, I would consider running on something that does NOT contain Sulphur - like propane. Otherwise the boiler is headed on a downhill side and once it starts to leak it is too late to convert to another fuel.

How long will this 'leakage take?' Impossible to say since to begin with, you probably don't know how much it already HAS BEEN run on coal.

Charcoal may work and suggest you try if you are game, but a 1" Atlantic will go through a LOT OF IT in an afternoon.

Alternately: If you like the loco running on coal (the boiler won't fail catastrophically), you can start to make plans to replace the boiler with one built using a gluing method that is Sulphur resistant.

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Re: Hydro Testing

Postby jscarmozza » Sun Aug 27, 2017 5:58 pm

Not exactly what I wanted to hear Bill, but pretty much what I expected. I appreciate your analysis, now I know what to expect. I have two 1" scale LE Atlantic projects, both with new steel boilers...so, when the time comes, one of them is going to be missing a boiler. In the meantime, I'm going to run it on charcoal; as I said, I make my own charcoal with the branches and prunings from the back yard, I'll just have to clean up the yard more frequently. Thanks again, I appreciate your advice. John


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