Maroln verse's Bronze Thru Hull and Sea Cocks

[JC47]

I am in the middle of a boat restoration project a 47' sail boat displacement 32,000 lbs. I am considering replacing all the thru hulls and sea cocks with the Forspar range of Marlon products. Do any of you have any negative or bad experience with these products. Do they become brittle over time. Thanks JC

[Hunter25]

You get what you pay for. Bronze can out live the boat. I have seen the plastic fittings crack from slight abuse, certainly much less then a bronze one can tolerate. A thru hull is not a place to try to save a few dollars, they need to be bullet proof or you will be testing your pump capacity.

[Tim B]

Be careful not to mix metals in a marine water system (or do so with care). Brasses and Bronzes are usually ok, but you may find that a plastic fitting, will make designing the rest of the system easier. It is also slightly cheaper and lighter.

Whatever you do, don't put a brass/bronze/copper skin fitting anywhere near a Steel (or Aluminium) hull. I have heard of it being done by owners, let's just say it was expensive, even though it was caught before it did too much damage.

One place not to skimp is the sea-cocks, a leak is serious.

Hope This Helps,

Tim B.

[Tim B]

Be careful not to mix metals in a marine water system (or do so with care). Brasses and Bronzes are usually ok, but you may find that a plastic fitting, will make designing the rest of the system easier. It is also slightly cheaper and lighter.

Whatever you do, don't put a brass/bronze/copper skin fitting anywhere near a Steel (or Aluminium) hull. I have heard of it being done by owners, let's just say it was expensive, even though it was caught before it did too much damage.

One place not to skimp is the sea-cocks, a leak is serious.

Hope This Helps,

Tim B.

[Tim B]

Oops, posted twice, sorry... Damn browser!

[JC47]

Thanks Hunter25 and Tim B. My intention was not to save money (allow though thats always nice) but to reduce the metals and the galvanic reaction that accompanies them. I do not want any type of failure and if the Marlon is not up the task then I will go the tried and true route of grounding all the metal (point taken about not mixing dissimilar metals). I have noticed more synthetic material on production boats wonder how they are standing up to the rigors of the sea in real life.

JC47

[DanishBagger]

Those people commenting "plastics" – are you sure you're talking Marelon, and not "ordinary" plastics, such as nylon or ABS? Huge difference in those products.

I haven't installed anything like that in my boat (it's not done yet), and it wont' feature sea cocks at all (it's a _small_ boat, lol), but Marelon seems to be a much tougher "plastic" than anything else. Hell, I have even tried hitting one with a rather big hammer. Nothing. Nothing at all happened.

Also, in comparing marelon with abs or nylon, I tried using a big pair of pliers to twist the collar, it was much, much harder on the marelon, whereas I could easily do it on the ordinary nylon.

Also, those marelon (not the nylon-ones, although they look alike) cleats doesn't seem to be as prone to degrade as the nylon ones.

But, anyway, I hope someone that actually has had some marelon seacocks will respond.

Good luck

[JC47]

Marlon seems to be proprietary to Forspar. They have rated the thru hulls tightening not to exceed 20lbs torque. Hopefully some one with direct experience with these products will, chime in.

JC47

[jonsailor]

I have used many a marelon seacock from Forespar and never had a problem.
My yachts are all composite so glueing them in is not a problem.

I have had to replace bronze fittings after many years due to the very slight corosion found but this is very independant to the yacht and electrical enviroment and disimilar metals that may surround the fitting.

I say go the marelon but they have never been in the light of UV's so be carfull if direct sunlight is a problem because I know the same material gets a powdery look on hatch handles.

[johnW]

I used marelon on a boat I built 20 years ago (FRP) and sailed it over 20,000 miles through out the Pacific. Never a problem except remembering to lubricate and operate them every 6 months or so. If left longer they became hard to close. Sold the boat and the new owers still have not replaced them. I am using marelon on my new aluminium boat with no reservations. Looks like the design has evolved since my first ones, which I think came from England.