Marelon Seacock Maintenance/Lube

[AaronJ]

Hi, I have 4 Marelon seacocks on my Hunter 30. I open and close them periodically to keep them loose. Am I supposed to be lubricating them with grease, as well?

Thanks,
Aaron

[Aqua Vitae]

Yes. They need petroleum jelly or teflon lube or the like annually. This will prevent the plastic from drying out and having the much-feared snapping off of the handle. If you aren't doing this during haul-out, I would simply pull off the hose and put some on the ball of the valve. When the hose is back on, move the valve open and closed to distribute the grease. I have a lot of faith in Marelon, but there is no need to tempt fate.

[David M]

The Marelon bypass valves for my head are completely locked up. I have no faith in them. I am changing over to bronze ball valves. I don't think the price difference is worth the hassle and the danger of not having valves working when you need them to work. Ask anyone at a boatyard who deals with these valves, it is very common occurrence for their handles to break off as a result of them seizing up.

[Therapy]

I think that is because people seem to think plastic lasts forever by itself.

Maintaining Thru Hull fittings

[David M]

Sure, all valves need to be worked periodically, but the incidents of Marelon valves failing is very high compared to metal valves. Just ask any boatyard mechanic who deals with these.

[jdoe71]

Our last boat had all Marelon seacocks, we made a habit of "exercising" them at least once a week. Never had a problem. Current boat has mostly Marelon but for two brass/bronze coloured ones. They have greenish efflorescence on them that looks like corrosion. Going to change them for Marelon ones which don't corrode. And continue to "exercise" them once a week.

[s/v Jedi]

All my posts about Marelon valves vs seacocks seems to go un-noticed so I give up on that subject. Sometimes it's very hard to break through peoples programmed auto-responses, like the senses and interpretation is shut down momentarily... like an instinct reaction almost ;-)

cheers,
Nick.

[bobfnbw]

Had all my bronze thru hulls/sea cocks replaced with year with marelon after a total failure of the thru hull due to corrosion. So far they are doing well. I have had no issue with them seizing up or difficulty with operating them, but of course they are new. Older ones will need the hose taken off, then greased, then operated a few times to distribute it. A hassle sure, but so was the bronze ones letting go.... And for what they cost, I can afford to replace them every 10 years or so if need be.

[GordMay]

From Forespar’s instructions, as previously linked by Therapy.

Marelon® - Marine Grade Plumbing Systems Valve Lubrication

As a follow up to previous Tech Tips; it is important to know that while Marelon® fixings are corrosion resistant, they do require twice yearly lubrication maintenance ...

➥ Maintaining Thru Hull fittings