3 1/2" Tich

[spurley]

Hi there

I am building a 3 1/2" Tich using the 1972 book and 1968 drawings. I have a rolling chassis now and have reached the cylinder machining and erection stage and wonder if anyone could suggest a suitable alternative to graphite string packing for the piston ring? I am researching some books I have at home here; Tubal Cain's ME handbook, Martin Evans' Model Locomotive Contruction and Stan Bray's Model and Miniature Locomotive Construction but would welcome any practical advice/suggestions please. I am thinking of some form of O ring either PTFE or similar.

Help Please

Cheers

Brian

[Tel]

Yo Brian, twist some teflon tape into a string and use that instead. Personally I don't like O rings for this application, but some folkses have success with 'em.

[JohnP]

I've been having no end of trouble getting graphited sting to make a decent seal. For one thing the ends fray as oon as you cut the stuff, and even when I get it in I've not been happy with the amount of steam blowing past the packing. Since PTFE tape is so readily available, I'd follow Tel's advice.

Regards,

JohnP

[spurley]

Thanks chaps, has the PTFE tape been proven in service?

Cheers

Brian

[denis M]

Dont Reeves or someone like that do piston rings