Regular fabric duct tape can replace hemp, which plumbers use to seal threaded pipe joints and faucets.
For this small strip you need to break into thin strands which are then twisted into flagella that can spin at screwing any plumbing fittings, and they will successfully play the role of a reliable sealing gasket.
Recommend to read
ON THE WAVES – “MOTH”
Ultralight Dinghy international class "Moth" "the Moth" (Fig. 1, 2) simple in design, convenient in construction and possesses all the essential qualities of sports ships - fast,...
ON ONE BOARD WITH A SAIL
Of course, sailing the Board someone able to buy in the store. However, most can't afford it. Such will want to do it yourself. Especially since there is no design supercomplex forms. To...