Seacocks - What Material ?

[micah719]

Thanks Cap'n Bill....I'll look further for those last two. Hmmm perhaps Marelon might be viable after all. I'll save final judgement for when I'm in better position to do a little destructive testing of both....fun fun fun!

[colemj]

Originally Posted by cburger

"My instincts" tell me I could probably knock it off with one good wack with my 1lb hand sledge, way less than an engine falling from a couple of meters. As stated I have worked with both products.

I have worked with both also. Your "instincts" are wrong. I have done that test.

Mark

[colemj]

Originally Posted by Sailorman375

Problem with marelon is not the material, but the weakness of the stem and that fact they must be cycled often to avoid them seizing. Again, the stem is the weak link here.

That is why I recommended the OEM 93-series. These are much different animals than the common ones found in most chandleries. Even though the 93's are sold to boat builders OEM, Forespar will sell them to individuals.

Mark

[colemj]

Originally Posted by S/V Illusion

Do any high end boat manufacturers use marelon valves?

Manta Catamarans and Endeavorcat used/use them.

Don't know why "high end" matters - lots of bronze ones on low end boats.

Mark

[colemj]

Originally Posted by bobconnie

Ive seen 5 yr old marelon so fragile from heat in the engine room they were installed in you Could break them with a small ball peen hammer !! I know I could have kicked it and done the same thing !!

It is more likely that you had difficulty recognizing and differentiating marelon from another plastic.

Mark

[colemj]

Originally Posted by cburger

On a shear load basis the plastic fantastic will fail way before a quality, flanged bronze properly installed seacock.

Again, on a shear load basis, the flanged bronze seacock will fail way before seacocks of other materials. So why stop at bronze? Why draw the line at marelon? Your logic seems arbitrary to me.

Mark

[S/V Illusion]

Originally Posted by colemj

Manta Catamarans and Endeavorcat used/use them.

Don't know why "high end" matters - lots of bronze ones on low end boats.

Mark

True but the converse is not!
To state the obvious, high-end boat builders typically choose the best materials which, in part, differentiates them from the competition. As is true of most consumer goods from airplanes, cars, electronics, etc... I mention it only because I personally value their opinion more than that of some people on the internet who may be biased, have some pride of ownership or not as well informed.

[Caribsailors]

4 more to go and mine are all marelon!
Next haulout.

[savoir]

I cleaned 6 Forespar marelon seacocks last April and all 6 needed nothing more than a rinse and a wipe to remove a little weed and dirt. All are 7 years old. All came apart very easily.

[savoir]

Originally Posted by S/V Illusion

Do any high end boat manufacturers use marelon valves?

Morris use Forespar marelon

[sailing_jack]

The problem with bronze these days is if they are made in China, the metallurgy is suspect.

[sdowney717]

Plastic Marelon is destroyed by lightening

BoatUS.com - Seaworthy Magazine

Giving the lightning a low-resistance path to the water is a good idea, but if it’s not done right, the damage can be even worse. The owner of a 27-foot sailboat bonded his through hulls properly with heavy wire, but didn’t realize that underneath one of the seacocks, the through-hull fitting was made of Marelon—plastic. When the boat was struck, the lightning dutifully followed the wire, but instead of continuing to the water as it would have through a bronze fitting, it jumped across the plastic one, destroying it and partially sinking the boat.

So when your struck it can sink the boat when you use these plastic seacocks.
USCGaux also is repeating the same warning notes on Marelon

http://www.uscgaux-ocnj.org/Webwatch...r_May_2012.pdf

[Fuss]

Originally Posted by sdowney717

Plastic Marelon is destroyed by lightening

BoatUS.com - Seaworthy Magazine


So when your struck it can sink the boat when you use these plastic seacocks.
USCGaux also is repeating the same warning notes on Marelon

http://www.uscgaux-ocnj.org/Webwatch...r_May_2012.pdf

Well, if you do some lightning strike research, you will see that bonded bronze seacocks even with bronze through hull fittings sometimes blows a hole through the fiberglass, sinking the boat.

If you are worried about lightning strikes and /or have bonded your seacocks, then the safest route for fiberglass boats is to remove them and replace with a marelon through hull with a marelon seacock.

There is then no chance of the through hull being blown out of the bottom of the boat.

[sdowney717]

Originally Posted by Fuss

Well, if you do some lightning strike research, you will see that bonded bronze seacocks even with bronze through hull fittings sometimes blows a hole through the fiberglass, sinking the boat.

If you are worried about lightning strikes and /or have bonded your seacocks, then the safest route for fiberglass boats is to remove them and replace with a marelon through hull with a marelon seacock.

There is then no chance of the through hull being blown out of the bottom of the boat.

Everyone has their own opinions.
Bonding wire did not help
yours versus this

When the boat was struck, the lightning dutifully followed the wire, but instead of continuing to the water as it would have through a bronze fitting, it jumped across the plastic one, destroying it and partially sinking the boat.

[CarlF]

I know the PO said that cost didn't matter, but have you guys recently priced new Spartan sea cocks?

They are the only bronze one's I'd consider. The other "bronze" seacocks are a crap shoot - mixed metals, mystery Chinese makers, you name it. Don't be fooled by the brand name. Ten years ago almost all sea cocks were made in Europe or the US. No longer.

The only Marlon worth installing is the Forespar OEM 93. I have never heard of an OEM 93 handle breaking - or other breakage problems (anyone?).

Those handle breaking problems are all from the regular Forespar sea cock - entirely different construction from the 93. I don't know why Forespar keeps making them because it gives them a bad name.

The Spartan will last forever (but you need to take them apart once a year to keep them really smooth and leak free). The Forespar OEM 93's will last longer than forever and just need to be exercised once a year. Installation is simpler (no thru-bolting required) and they cost less.

Carl