Evenin folks 

Question, as my new oil pressure sender and T bar needs fitting and i have approached this task with a great diligence,,  ie read the distructions properly 
now they say to use a teflon sealing compound to ensure a proper fit and keep said sender earthed through the thread, google says you can only get this from the yanks, so £ on buying and £ on shipping??
Could i use some plumbers tape over the last half of the threads?
Is using an oil resistant o ring adequate?
or a mix of the last 2 ?
or is there a 5th choice anyone can tell me about ??
Rich 

Copper washer as per the VW sender they shouldn't be a tapper fit, you run the risk of a cracked case if it is.

Its not a vw sender flags,, its an Autometer sender there was no washer or o ring with it

As Flags says or a dowty washer provided the new take off has a flat face at the end of the threads.
If not using a sealing compound sparingly towa ds the outer end of the thread will get a good enough earth as it is not a high current flow joint.

If you need to use a sealer just use a liquid PTFE, not tape, the extra bulk of tape can crack blocks and fittings.

http://www.screwfix.com/p/no-nonsense-ptfe-liquid/40302

Thanks flags, snoopy,, get what you both mean now,,
i'll look at getting the right size asap,
and if i end up with a leak i'll look at that ptfe Dave

cheers guys