Rudder gland packing - Graphite or PTFE type?

[PetiteFleur]

I've got to renew the gland packing on my boat as it's obviously been leaking and it's now all green. Which is best, Graphite or PTFE ?
Also, as it's an old boat and ¼" packing, is it ok to use 6mm as these seems to be easier to obtain nowadays?

 

[Spyro]

I'd say 6mm is ok as it will squash to take up the extra space. Quite a few posters reported overheating when ptfe was used in shaft seals, myself included but as this is for your rudder I'd say either is ok.

 

[vyv_cox]

I'd say 6mm is ok as it will squash to take up the extra space. Quite a few posters reported overheating when ptfe was used in shaft seals, myself included but as this is for your rudder I'd say either is ok.

On sizing, it is not critical. Both types deform easily and some owners with 7 mm gaps find that this size is unobtainable. 8 mm packing responds well to light hammering and is easily brought down to size.

Glass filled PTFE, which is the common white stuff, wears stainless steel quite badly.

 

[ghostlymoron]

On sizing, it is not critical. Both types deform easily and some owners with 7 mm gaps find that this size is unobtainable. 8 mm packing responds well to light hammering and is easily brought down to size.

Glass filled PTFE, which is the common white stuff, wears stainless steel quite badly.

I guess this would rule out PTFE for sternglands as well, Vyv.

 

[<152587>]

Graphite packing is used for steam systems where the temperature would melt the impregnation, graphite provides the lubrication in these cases. PTFE is commonly used in the food industry. The correct packing for stern glands and rudder glands is tallow impregnated flax. It is common practice to lightly planish the packing with a hammer prior to insertion into the gland as when compressed it will take up so exact sizing is not an issue. Suggest you research the Klinger.co.uk website for confirmation. In my opinion Klinger K1 is acceptable.

 

[vyv_cox]

ASAP sell either graphite cotton or PTFE flax. They state that either is suitable for both jobs.