Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: parallelmotion on March 13, 2024, 01:47:36 pm
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Problem solved!
A good day Brent. :)
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Thanks Bruce. It was never clear to me that the boiler was being over-filled, although that was the case, maybe by only a few ccs. But even that wasn't enough as there were other factors involved which made this so puzzling. Video is now posted under the Videos heading.
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Glad you figured It out Brent, over filling the boiler makes a lot of sense now.
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Congratulations!
I'm delighted to hear that wonderful engine with fountain is going to be just fine. Glad you stuck with it and got to the bottom of all the problems!
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Problem SOLVED. Well turned out to be a perfect storm of a combination of factors. 1) First problem is that the boiler capacity is smaller than I had calculated--yes, I should have measured it directly and now filling to only 75 ml rather than 100, 2) steam leaking from the safety valve gasket and fitting for the steam line. Even a replacement gasket has to be screwed down hard to keep it from leaking; sv itself was fine. This combination resulted in very low pressure in the boiler, and both are now sealed tight with no leaking, 3) wicks on the burner were too high resulting in vigorous and rapid boiling (now trimmed to just a few mm of height. Changing only one or two of these things did not help but by fixing all three, the problem was solved. Thanks everyone for your suggestions and hopefully this will be of help to someone in the future. Watch for a new post with a video of the engine and fountain. Thankfully the engine itself is no longer the fountain.
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Thanks but there was no change when I held it down--just let it go for the video clip. No shaking on air. I think the imbalances with all the water flow caused the shaking.
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The shaking in the run might have been enough to froth the
water to such a degree that it went into the steampipe.
Does it shake at all when running on air?
Wayne
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Thanks but timing is fine--runs great on a few pounds of air. Also no difference even when I hold it down with no sloshing. Safety valve is not opening but could be a worn or corroded valve seat/stem. Will check that tomorrow. I think it's the fist time running in decades if not longer.
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If that doesn't help, check the timing in the slide valve on the cylinder. The shaft length
might need to be adjusted. It's shaking so bad that it might be trying to pump in and out
and with all of the shaking, water splashing against the SV is being pushed out.
How long have you had this set up? Did it run OK before or is this your first run of it?
It's a beautiful set and if you like, I'll take the troubles away.
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You may well be onto something there.
Insufficient pressure / temperature may well be putting "cold" steam into the steam line.
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Now I think there may be a problem with the safety valve. The stem was badly oxidized and had to remove a lot of green residue from it. The gasket is new and the tension is good but it might be leaking steam (and water?) through the valve stem. I'll test that tomorrow and make a new stem if necessary. Insufficient steam pressure may lead to the water intake in the engine.
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As you can see the steam line to boiler fitting is normal and doesn't extend beyond the thick top of the boiler. Also just did a thorough hot degreasing/cleaning of the boiler. No change--still gushes water like crazy. What's going on here?
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Thanks guys. I'll decontaminate the boiler but there's no sign of foaming anywhere and never heard of this being a problem for tiny boilers, but it's worth a try. Boiled water also comes out looking very clean. The fitting for the steam line has two internal diameters forming a socket for the line to be soldered into, so it's impossible for the steam line to extend beyond the fitting into the boiler. Sounds unlikely, but maybe the fitting itself is too long due to a factory screw-up, who knows.
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Haha Daniel posted at the same time as me :D
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I would guess priming because of some type of contamination in the boiler causing the water to foam inside. Have you tried cleaning the inside of the boiler?
Or, Not likely but could someone have replaced the steam line or the original be too long and down inside the boiler near the water level? Can you see inside with a light or small bore scope?
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My best guess would be some kind of contaminant (steam oil possibly) in the boiler, that is causing the boil to be frothy, bringing lots of water to the top of the boiler where it is sent out the steam line and SV ..... maybe?!?!
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Thanks. What exactly do you mean by "priming"?
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Is it possibly priming badly for some reason ?
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Thanks Bruce. It runs great on 3-5 psi. Tension on the slide valve is adjustable so I can try tightening that a bit. But why would this cause all the water getting through?
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The little bugger rocks,shakes & wants to jump off the table for trying. My initial thought is very worn valve tolerances or piston slop. How does it run on air ?
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I've restored and run well over 100 toy engines on live steam and have never run into this particular problem. This little Carette loses over half of its water after boiling through the cylinder and out the exhaust--or whistle if left open--almost empty within minutes. The boiler capacity is about 175 cc and I'm filling with only 100cc. I've also cut down the burner's wicks to where the burner can barely power the engine. Still no change. Is anyone familiar with this problem? I'm baffled by it (please watch the video clip). To add insult to injury the engine is part of a fountain. A little condensate is normal but this is ridiculous. What am I missing here? Thanks in advance.
https://youtu.be/IDcmmr-IsGM?si=0pirU5ZYy1Mkkrv8