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

I use Hot water heating and mounting paste -
this is a waterproof grease used in the assembly of water pipes together with hemp. In any case, use grease for your pump - not oil or WD 40. I use this grease also for all threads on and around the Boiler - they always unscrew.
Arnold

It is non toxic and heatable up to 375 °F - I think you should find a similar product in the US

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