Oh no... I just replaced head sanitation hose

[Nicholson58]

You might build up a hose barb with self amalgamating tape.

[Rotten Ricky]

Originally Posted by Nicholson58

You might build up a hose barb with self amalgamating tape.

You beat me to the suggestion.

Compression or stretching of rubber or plastic hoses have their limits. Just because you can get two items to come together does not mean that it will not split or crack and sink your boat at a later time!

Stretched fairly thin, rubber self-amalgamating tape bonds to itself and the barb, which is a far better option than anything else to build up the fitting slightly. In particular, do not use electrical or similar tapes as the adhesive can deteriorate with time, become slimy, and the hose could slide off the fitting.

In some cases I have installed a tiny self-tapping screw near the end of the barb fitting to make sure that a clamped hose cannot slide off. It does not leak cos screw pan-head is covered by the hose, and the double hose clamps are closer to the end of the hose. Don't have the screw protrude far enough into the barb that the deleterious head contents can hang up on it and create a blockage.

Lastly, if you try using a liquid sealant like 3M 4200, Sikaflex etc, apply it - but do not tighten up hard on it until the next day. This allows the sealant to become hard-ish. The later tightening means that your perfectly-formed custom rubber gasket is compressed - rather than squishing out of the area when still liquid. If you tighten up quickly, you are only relying on (hopefully) non-deteriorating adhesion to seal it and that it will be maintained. But if it is under compression as well, it is also mechanically sealed and virtually impossible to leak. This is especially true when installing thru-hulls etc, in spite of the curve of the hull under the water line!

Cheers, RR.