Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

graphite yarn or teflon yarn for rings available at local plumbing supply works well in small steam engines as well, and really no break-in period.
crazydoug

Yep!  But the engine itself, after machining, need break-in period.  If his engine feels "stiff",  I imagine it can origin from some mechanical friction caused by no or bad break-in.  Same thing if the builder choose to use, for any reason, o'rings instead of teflon or graphite...