LTD to HTD Stirling engine converstion

[Tom Booth]

...

The bottom silicon gasket I made for that engine eventually melted, with repeated testing at over 1000°F.

The next step in my rebuilding efforts is to find or make some more reliable high temperature gasket material for the bottom plate.

A silicon oven mat type material seems to work fine for the cold plate.

I did just come across what I think may be a relatively new material as I haven't seen it previously and I've been looking off and on for a very long time.

An Amazon description says it is used:

..flexible graphite material has been proven for more than 30 years in industrial applications, where temperatures routinely exceed 2,000 degrees-day after day, week after week, year after year

Sold as a DIY exhaust manifold gasket material. Can be cut with an exacto knife, but expensive. About $60 / sq ft.

I have a suspicion that it might not be too difficult to make. Graphite itself is inexpensive.

Maybe crush up some pencil led and mix it with something like??

[Tom Booth]

Another flexible graphite gasket manufacturers website mentions:

"Non-oxidizing Environment: Up to 5400° F (2980° C)"

Not too shabby. Even a gasket for an atmospheric air filled Stirling/hot air engines would have limited air contact, and for a helium filled Stirling, oxygen would be virtually non existent, inside the engine anyway

This stuff should be able to withstand even a hydrogen gas flame, which ultimately would be my goal.

[Tom Booth]

While partially assembling the engine, checking how the new piston works in action and so forth, I was thinking if, and/or ways in which it might be possible to lengthen the power piston throw for increased compression ratio.

Suddenly the crankshaft came apart in my hand.

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Maybe it wouldn't be all that difficult. Apparently the parts are only pressed together rather than welded.

[Fool]

I've had good luck with Locktite bearing retainer.

I don't know if it would help any but I've heard it is possible to glue glass to glass in a permanent bond using sodium silicate water glass and heat treatment? Glue the hot end and use a silicone gasket on the cold end of a glass displacer chamber?