# A Stuart Beam Project . . .



## GWRdriver (Oct 22, 2009)

This is a Stuart Beam engine I built a few years ago and although it was not my first Stuart engine it was my first beam engine and it was not as simple a build as you are sometimes led to believe. It's a stock Stuart Beam kit built essentially to their drawings with the only deviations being in the minor details and fitting out. The engine is no longer in my possession because it was built for the collection of a fellow in Detroit who is now deceased. Unfortunately I no longer know where the engine is and I was told that before his death he . . . ummm . . . considerably "improved" it.
	It's unfortunate that I didn't do a better job of photographing it before it left my shop. The surviving photographs are marginal because they were made in poor lighting with a 35mm camera and subsequent scans and cleanups with such software as I have haven't improved them much. The color also is very badly off. Rather than being a bright red it was actually a deep red, almost a maroon.





	Mechanically, as I said, it is pretty much stock and as I recall I didn't run into any design or dimension discrepancies in the basic model. I did however discover that if installed it as-drawn the governor flyballs would foul the flywheel rim at full twirl so I moved the governor stand away from the flywheel a bit. Most of the bright metal bits were finished either with a final lathe cut, sometimes using a watchmaker's graver, or drawfiled with a clean flat file. Those are my favorite finishing tools and nothing on it was polished.
	Of interest might be the engine room floor treatment. The base was a box frame built of a hardwood, mahogany IIRC, deeply rabbetted with a 3/4" plywood subfloor glued in. Laid in over the subfloor is a surface of "Corian" countertop material which was not glued or permanently fixed in place. The tile effect was achieved by routing the Corian with a thin slitting saw (maybe .020") in the mill to a depth of maybe .025". Since Corian "picks" badly at sharp edged cuts I had to mill carefully to prevent a ragged edge. I then made up a "grout" of "Plastic Aluminum" (much too light) and "Plastic Steel" (much too dark) mixed and thinned with acetone until I got just about the right consistency and color. The slits in the plastic were then grouted just as you would grout bathroom tile and the entire surface simply block sanded with 100gr paper. I treated the Corian base virtually like a metal and drilled and sometimes tapped it as required for all the mounting bolts. It's dimensionally stable enough not to cause shaft alignment problems, at least for this engine.
	Painting was a real chore but I'll start first with the prep. Aside from the obvious which was to do all I could by hand to make things ready to receive a good paint job I also applied and worked down a coat of Sherwin-Williams Ultra-Fill automotive filling primer. I really had misgivings about this as I'd had a couple of very bad experiences with overly thick primers and fillers before but it turned out to be great stuff. I was not an experienced or good painter, and I'm still not, I just managed to survive this one and come out on the good side.
	As for paint, some years ago I had a can of machine enamel made by a well-known industrial paint mfg which gave me beautiful results even when brushed. I originally wanted the engine to be a forest green and I went to same mfg to get a green mixed in the same paint but when I applied the paint (by automotive spray gun) it behaved completely differently. It simply never dried. After weeks. Or ever. It was a disaster and the entire engine had to be stripped to bare metal and finishing started all over again.
	I ended up using a paint product called "Hobby-Poxy", a two-part epoxy made by Pettit Marine for the airplane guys, and their maroon was the only color I thought was appropriate for an old British beam engine. I don't think Hobby-Poxy is made any more but it was good stuff and hardened out well. I spent a fair amount of time masking areas to be left unpainted and then scraping errant bits of paint off places where something had to be metal on metal.
	That's about all I can remember about the build, aside from using a 3-stone automotive brake cylinder hone to finish the cylinder bore. I've since had a number of people tell this will never work, it won't ever be "right", but it worked beautifully for me, then and now. All in all it just took time, and care, and a desire to do a good job.


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## gbritnell (Oct 22, 2009)

That's a classy looking build. I really like beam engines with all their linkages. Maybe someone can identify the new owner for you. I don't see many Stuart beams at the shows I go to.
gbritnell


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## zeeprogrammer (Oct 22, 2009)

Thanks Harry.
Nice looking engine and I enjoyed the detail in the post. Very helpful. Thanks again.


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## Orrin (Oct 23, 2009)

Thank you for a very interesting write-up, Harry. The "how to" of the Corian base is greatly appreciated. 

I also use a brake cylinder hone to produce the final finish on my cylinders. It "works a treat" as the Brits would say.

Best regards, 

Orrin


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## GWRdriver (Oct 23, 2009)

Orrin,
The Corian made for a very good simulated stone base. There are a dozen other brands of cast acrylic polymer sheet and they all of course offer an array of colors, not all of which are suitable for engine room floors! The color I used had several things going for it IMHO. The color was neutral and subdued and doesn't divert attention from the engine, it's a reasonable simulation of a marble or light limestone, and most importantly it was one of the most commonly used colors for baths and kitchens so it wasn't to difficult to a free piece in a cabinet shop scrap bin.

It's a brittle material, strong in compression but susceptable to chipping in tension thus the sawing had to be shallow and done carefully using a hollow ground slitting saw. I toyed with the idea of using a pointed d-bit, such as folks use to scribe divisions in lathe hand dials, but I didn't want to take the chance that the grout would pop out so I elected to go on with a slitting saw and it came out well enough. I have since made bases for other engines using the same materials an technique.

The other thing that was kind of tricky was applying the grout. Since the color was the result of a mix, and since it was volatile and hardened quickly, I had to mix enough to cover the whole base with one color and get in all rubbed in before it set up. Having 2-tone grout wouldn't do! What one has to do is work fast and not pay too much attention to how messy the grouting operation is because in the end it all gets sanded off to expose only the joints.


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## GWRdriver (Oct 23, 2009)

gbritnell  said:
			
		

> I don't see many Stuart beams at the shows I go to. - gbritnell


G,
Thanks for the kind words. I don't get to many shows, and we have none to speak of down here, but I've been to NAMES several times and it's apparent that agricultural and IC subjects are the favorite subjects, and more power (no pun intended) to them. Although we certainly had them, everywhere, the beam engine isn't something that lingers in the US historical eye as it does in England hence possibly the lack of popularity, but it's probably a combination of a number of much less philosophical things - castings price, availability, difficulty of build, peer interest (ie, wow factor), etc.

Several of the best model steam engines I've seen in the US, including a magnificent Stuart Major beam engine, were built by a fellow named John McDivitt from PA. They were beautifully rendered out and had a superb and convincing balance between bare metal and painted parts.

PS - I just now found your write-up of your model 302 and it deserves all the admiration it has received. It's an admirable accomplishment. I'm in particular awe of multi-cylinder IC projects because that's probably the sector of model engineering technology I know least about and therefore am most intimidated by.


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## Jeff L (Oct 25, 2009)

Harry, beautiful job on the Stuart Beam . You mention John McDivitt in your last post , John was a good friend of mine and he built 3 Stuart Major Beam engines in his lifetime .Jeff


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## GWRdriver (Oct 26, 2009)

Jeff L  said:
			
		

> John was a good friend of mine and he built 3 Stuart Major Beam engines in his lifetime - Jeff


Jeff,
You and I may have corresponded re John after he passed away. Here for everyon'e enjoyment is another John McDivitt engine, a "Lane & Bodley" Corliss. Designed by Charles Heckel, published as a construction series in the "Model Craftsman" magazine, beginning Sept. 1938. Flywheel diameter 10", o.a.l. about 16". Redrawn and republished in Live Steam, August 1991.


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