Stirling Engines and the lubricant used

[fireant911]

I have always been fascinated by engines in general. Late last year I opted to purchase a Boehm stirling or heat engine produced by a company in Germany. You have several models to chose from in either as a kit or fully assembled - I ordered the kit for the HB14-AO4 from a german seller on Ebay. Although these are far from cheap (I think mine was around $250) they are extremely captivating to run. Now for my question... they use an extremely fine coating of 'ceramic paste' as the lubricant on the piston. What is this ceramic paste? I know that it is white in color and has almost a dry texture but what is this stuff?

Here is a link to the Boehm site if anyone is curious.
http://www.stirling-technik.de/htmlpages/home_engl.htm

[AFJuvat]

From the site.

> Frequent mistakes during mounting: too much Ceramic paste on the working piston!! Always let run dry first to check operation, then apply waferthin according to construction.
-> If your motor does not not start anymore, first remove and clean the piston as well as the cylinder inside, after drying assemble and test. Now apply the Ceramic paste again according to instructions.
-> Never apply oil to the piston! Otherwise the motor stopps.
-> While mounting the dowel-pin press the pin from that side, from which it gets stuck on its own, so it can be pressed in with long-nose pliers. (Check from both sides: from one side the pin can be pressed in a little and gets stuck.)
-> All types are readily greased and must not be lubricated anymore.
-> The enclosed injections are not supposed to grease occasionally but exclusively as lubricant for re-assembling resp. after a complete cleaning (after dismantling).
-> Additional greasing only causes stroger soiling and brings the motor to a standstill.

EDIT: they have the paste on the website for 5 euros

1 Spritzchen 0,1-0,2 ml Böhm Spezialöl für Verdrängerachsen Euro 5,-

http://stirling-technik.de/htmlpages/deutsch/bestellung1_dt.php

[kach22i]

What are you going to use the engine for?

Neat.

[fireant911]

kach22i,
The engine serves no practical purpose for me other than, to use a play on your own words, a huge 'neatness' factor. I had read a book entitled The Next Best Thing that really made my interest grow. The facility that the book was based on (SunPower) worked on the development of solar-powered Stirling engines for power generation. The whole science behind these engines is simple thermodynamics but is amazing in operation. A couple of times a month I fill up and light the burners, give the flywheel a spin, and let the engine run.

I remember reading that a Swedish (I think) manufacturer was working on the development of yacht generators using these engines because of the quiteness factor associated with the operation. NASA had also done some rather extensive testing (>86,700 hours) in a stirling engine powered by a radioisotope to supply power for objects in space. The engine ran continuously for 10 years without ever being stopped for anything.

[kjb]

The Swedish Navy has been playing with Stirling engines in submarines for 20 years:

http://www.kockums.se/Submarines/aipstirling.html

/ J

[M.D. Holloway]

Daryl,
I think I have something that will work well for you. Send me your shipping address and I will get it out to you.