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Advice needed on steam engine repair

I have a minature steam engine - heated by electricity. It has a 1/4 in OD brass threaded pipe that has a needle valve on top that feeds steam to the cylinder and also holds the cylinder, flywheel etc to the boiler. It has been broken about a 1/4 in fron the end that goes into the boiler.

I would like comments advice criticism etc on my plan to repair. I need to butt solder this little pipe so I found a number drill bit that would fit snugly inside the pipe to hold it straight - then if I put a washer over the drill bit so I could lightly clamp it together - could I then silver solder it with a butane mini torch with a chance of it holding....I could shim the pipe so I wouldn't need to have the threads be ok where it broke.

Would I solder the drill bit to the pipe - would coating the drill bit with grease or something stop that?

Anything else wrong with my plan - I admit that I do most of my metalworking with a hacksaw.

Thanks for your help. John noid at austin dot ibm dot com

Reply to
John Noid
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I can tell you the grease will come out and contaminate weld.

Reply to
HaroldA102

The best way would be to sleeve the pipe with another piece of pipe and solder all of that together. Soldering with the drill inside will tend to also solder the drill inside and you will have to pull all of it apart again. In addition, butt soldering the pipe will not have the same strength as the pipe itself and that will cause another rupture at that point.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works every time it is tried!

Reply to
Bob May

Thanks I was afraid of that. Does anyone know of a source for pipe that OD is the same as a number 25 drill bit? I can't sleeve it outside since it runs thru the cylinder "steam feed" mechanism. I don't think that it needs a whole lot of strength especially if it doesn't (I suspect) get dropped again. I have some silver solder that reads - cover part to be solder with flux - the solder will not stick to the parts that don't get covered. Is that my salvation? I also figured I could solder the threads together at the point of breakage since I could shim the piece so that those threads were not needed. Thanks

Reply to
John Noid

metalworking

If you can get both pieces of the pipe off the engine you can probably silver-solder them together and they'll be strong enough without re-inforcement. The pipe was only brass to start with, after all; and it will be annealed after you're done and so is less likely to break again - it'll bend first.

What i'd do is hold the larger section with a set of large tweezers in a vise, so that the broken end is vertical; I'd flux the broken end and drop some teeny-weeny pieces of silver-solder (the real kind) onto that end after heating it with a propane torch. You have to heat enough that the solder flows onto that end of the joint-to-be. Then I'd flux the smaller part and set it carefully on top, just as it would have been originally. I'd heat the pair carefully - starting about an inch away from the joint, watching the top part, maybe holding it with tweezers or a bit of wire inside. The flux should bubble and then get glassy-sticky - at that point if the sections are aligned correctly you heat closer to the joint until the solder melts and flows; the top part will settle into place, and you dump it in the pickle.

Reply to
jtaylor

Any decent hobby shop will have K&S tubing which is telescoping. You may have to make the full end of the pipe to really do the job right.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works every time it is tried!

Reply to
Bob May

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