Re: steam engine need help!
Posted: Wed Dec 27, 2017 1:01 pm
Joe, I have about 15 years of experience in machine work, fabrication, and mechanical work, as well as some design of all 3. I've been into every part of a car/truck from rebuilding a brake master, assembling engines, to rebuilding a brake caliper that was hard to find a replacement for. I also built a very basic little 1" bore steam engine in tech school but only ran it on air. It was a simple thing that was aluminum on aluminum, but used Teflon rings top and bottom so the piston never touched the bore. I made a little billet connecting rod and even put bearing bronze in it, and offset turned the crank on the lathe in one piece from steel. One of the reasons I was able to make it, is because the school was really poor at supplying materials, so a lot of little remnants left from this and that gave me the materials to make the little parts:)
I don't mean to step on anyone's toes, but over the years I've always been one to think outside the box, and never accept "because this is way we've done it for XX years" as a logical answer. Technology and materials advance, and there isn't any reason not to look into them. My concern comes from the fact that we're powering a cast iron or steel cylinder with moist steam. Do as you may, but you won't get all the water out of the ring grooves without taking the cylinders apart after each run, and it *will* rust. The grit and scale from this rust will then slide back and forth and eat up everything over time. It's my opinion that a bronze piston, stainless cylinder, and Teflon rings arranged such that the piston never contacts the cylinder, would provide very low maintenance, no corrosion, and long life. 2nd choice would be bronze on bronze, with Teflon rings. If you like the look and rigidity of castings, they can always be lined. This is especially important to me, because IF I ever build a steamer, it will see regular use, and to make sense for me to have and operate, will need to be able to quickly build steam, and quickly/easily be drained/fogged/lubricated after use. Otherwise, it doesn't make sense to have it.
It's like my boat in a way, I have everything equipped with petcock valves and easily removable end-caps on the cooler so I can quickly drain and winterize my engine in about 15 minutes. There are "windows" for it's use defined by the amount of daylight, tides, when the fish like to bite, and when I have time to go, that I am able to make, because I can quickly "ready up" my boat, use it, and "put it back to sleep" afterwards. If I had to spend 2+ hours reaching in under the engine blindly threading in and out pipe plugs into holes with grit in the threads, like it was originally, I would lose many opportunities to use the boat.
I don't mean to step on anyone's toes, but over the years I've always been one to think outside the box, and never accept "because this is way we've done it for XX years" as a logical answer. Technology and materials advance, and there isn't any reason not to look into them. My concern comes from the fact that we're powering a cast iron or steel cylinder with moist steam. Do as you may, but you won't get all the water out of the ring grooves without taking the cylinders apart after each run, and it *will* rust. The grit and scale from this rust will then slide back and forth and eat up everything over time. It's my opinion that a bronze piston, stainless cylinder, and Teflon rings arranged such that the piston never contacts the cylinder, would provide very low maintenance, no corrosion, and long life. 2nd choice would be bronze on bronze, with Teflon rings. If you like the look and rigidity of castings, they can always be lined. This is especially important to me, because IF I ever build a steamer, it will see regular use, and to make sense for me to have and operate, will need to be able to quickly build steam, and quickly/easily be drained/fogged/lubricated after use. Otherwise, it doesn't make sense to have it.
It's like my boat in a way, I have everything equipped with petcock valves and easily removable end-caps on the cooler so I can quickly drain and winterize my engine in about 15 minutes. There are "windows" for it's use defined by the amount of daylight, tides, when the fish like to bite, and when I have time to go, that I am able to make, because I can quickly "ready up" my boat, use it, and "put it back to sleep" afterwards. If I had to spend 2+ hours reaching in under the engine blindly threading in and out pipe plugs into holes with grit in the threads, like it was originally, I would lose many opportunities to use the boat.