Forespar Through Hulls

[niteflite1287]

Has Anyone and any experiences (good or bad) with them, I was refitting my boat with Marelon seacocks when I unexpectantly found myself needing to replace the through hulls. So I was debating whether to use bronze or Marelon.

[maxingout]

I have had two Marelon through hulls fittings fail on Exit Only.

I was working in my starboard bilge, and my hand bumped into the 1/2 inch Marelon thru hull fitting that serves as the water intake for the head. The Marelon skin fitting snapped off flush with the hull, and I watched a small 1/2 inch geyser of water arch up into the air and then descend into the bilge. This definitely was not good.



I quickly put my finger in the hole and stopped the leak. Then I grabbed an emergency wood through hull bung/plug, and pushed it into the hole. I called my wife to get a hammer, and then I drove the wooden bung securely into the hole. Once again I was glad that I was on an unsinkable catamaran.

I called my friend Ted from yacht Tyche to come over and have a look. He surveyed the carnage, and we decided to change the thru hull fitting while the boat was still in the water.

I went over the side with my wet suit, a bronze thru hull fitting, a wood bung, and some 5200 underwater caulk.

When Ted pulled the wood bung out of the hole, I instantly jammed a new bronze fitting (caulked with 5200) through the hole in the hull. I plugged the hole in the new bronze fitting with a wood bung so that it would not leak while Ted tightened the nut on the thru hull from the inside and attached the new ball valve.



The bronze skin fitting transplant turned out easier than expected and courage rose in our hearts. Tyche and Exit Only were set to sail together across the Coral Sea to New Caledonia, and we decided it would be a good idea to change out the remaining eight Marelon thru hull fittings on board Exit Only.

The next day, Ted and I took the boat up the Mooloolaba River and attempted to beach the cat with only moderate success. We had an unfavorable tide, and all eight remaining thru hulls remained underwater during the thru hull transplants. By late afternoon, the dastardly deed was done, and Exit Only now had eleven bronze thru hulls. We motored back to Lawries marina in the dark hoping that it was OK to replace thru hull fittings while they were under water. (In the six years since doing the underwater skin fitting replacements, there have been no problems or leaks)

Comments:

1. We broke off 1/2 inch Marelon thru hull fittings on two separate occasions. One was the cooling water intake in the engine room, and the other was the water intake for the starboard head. It was only the small 1/2 inch Marelon skin fittings that broke. The 3/4 inch and larger Marelon fittings did fine, but we changed them out anyway.

I recommend that people change out their 1/2 inch Marelon thru hull fittings because they will eventually break off, possibly at an inopportune time. The small size Marelon skin fittings have a wall section that is simply too thin, and over time they will fail.

2. It's not that big of a deal to change out a through hull in an emergency while your multihull is still in the water. If a skin fitting ever breaks off, don't despair. You can easily fix it if you have the spare parts.

3. Be sure to have a wood bung tied to every skin fitting so that you can quickly plug the hole when a skin fitting fails. The wood bung quickly absorbs water causing it to swell up creating an extremely tight seal. You may find that it's hard to remove the bung when you change out the skin fitting. You might have to knock it out with a hammer from the outside.

[Evan]

I like the bigger sizes (1-1/2") for saving weight, but recently had a 3/4" size break the handle so it is not connected to the ball inside. You can turn the handle but the ball is stuck about 1/3 open...

[roverhi]

Forespar says the thru hulls need to be exercised regularly and lubricated. How you lubricate them in the water is a mystery. If you don't cycle them, the balls freeze in position and the handle breaks off when you try and force it.

Aloha
Peter O.
Pearson 35

[Christian Van H]

I cant be the only person on this forum that these stories scare. IMHO, no plastic below the water line. I just cant see what makes them worth the risk...

[Blue Stocking]

Does the Coast Guard still use the old "25lb @ 24" from 90 degrees" break-off standard? Or, what is the new standard?

[rtbates]

For me it's Spartan bronze seacocks. Why? The 25 year old ones on our Cape Dory function perfectly like the day they were installed.

[Strygaldwir]

I use titanium thru-hulls with Forespar Marelon ball-valves. I have replaced all the underwater thru-hulls. I have not replaced some of the drains above the waterline yet (just haven't gotten to it).

The "plastic" thru-hulls remaining, are significantly deteriorated. I'd expect that they would fail if they were subjected to any kind of impact.

[fishfinder]

[quote=maxingout;273992]I have had two Marelon through hulls fittings fail on Exit Only.

Maxingout -- how old were your thru-hulls that failed? And are you sure they were Marelon and not some other plastic? Wondering because the fittings in your picture don't look like the Marelon thru-hulls or ball valves I've seen, even old ones (but I could be wrong).

I'm replacing my 1/2" decaying bronze thru-hulls in a few weeks, after some research I'm leaning towards Marelon. The only negative thing I've heard about Marelon is the valve's handles have a history of breaking, never heard or seen anything about the thru-hull breaking off (major issue if Marelon breaks like that!). I have heard that other types of plastic thru-hulls can break like you describe though.

[maxingout]

[quote=fishfinder;275219][quote=maxingout;273992]I have had two Marelon through hulls fittings fail on Exit Only.

Maxingout -- how old were your thru-hulls that failed? And are you sure they were Marelon and not some other plastic? Wondering because the fittings in your picture don't look like the Marelon thru-hulls or ball valves I've seen, even old ones (but I could be wrong).
quote]

The through hull fittings were definitely Marelon. No doubt.

The first through hull failed in the engine room when the boat was 2-3 years old. At that point we went ahead and replaced both engine room through hulls with bronze.

The head intake through hull failed when the boat was about 7-8 years old. At that point, I replaced all the Marelon through hulls, because I was on a circumnavigation, and I didn't want a through hull failure offshore.

[s/v Jedi]

We love the marelon thru-hulls from Forespar. It is impossible to break them when installed correctly because the seacock will be covering the thru-hull 100% and that one is bolted or screwed onto the hull. The examples given are another case of using thru-hulls with valves instead of proper seacocks. Bronze thru-hulls will fail in that scenario too but can take a bit more abuse (it -is- abuse, no thru-hull is designed to cope with that situation because it should never end up in it).

The forespar seacocks do not seize with broken handles as a result. The forespar ball valves do this only when the two parts are assembled too tight (which happens during attaching fittings without stopping the valve parts from tightening. Yes, these valves are two parts, you can undo them to get to the ball.

cheers,
Nick.

[fishfinder]

Wow yeah those are major failures. Wonder if you had some early version of Marelon then. That valve looks like something from home depot. I'm assuming Forespar fixed the issues you were having because if Marelon was that unreliable today, nobody would use it. It's being installed all the time, even as OEM.

[bobfnbw]

Originally Posted by s/v Jedi

We love the marelon thru-hulls from Forespar. It is impossible to break them when installed correctly because the seacock will be covering the thru-hull 100% and that one is bolted or screwed onto the hull. The examples given are another case of using thru-hulls with valves instead of proper seacocks. Bronze thru-hulls will fail in that scenario too but can take a bit more abuse (it -is- abuse, no thru-hull is designed to cope with that situation because it should never end up in it).

The forespar seacocks do not seize with broken handles as a result. The forespar ball valves do this only when the two parts are assembled too tight (which happens during attaching fittings without stopping the valve parts from tightening. Yes, these valves are two parts, you can undo them to get to the ball.

cheers,
Nick.

Ah nick, need your advice once again.
Something I did left some stray current on board, and yesterday I got a call from the marina that my boat was taking on water. seems one of the head bronze fittings was leaking bad, and the keel was on the bottom, with 3 feet of water onboard. The one bilge pump I had aboard failed(yeah I know very dumb on my part, was replacing tanks and bilge pumps and hose, and left the other one unpluged. We got her pumped out and hoisted. Found MAJOR electrolysis damage on all the underwater thruhulls. Very bad. The boat was last hauled last august for a survey and all found to be ok. So this is a quite new event. Their is a boat show here not and they made me move my slip, which had 50 amp service, And my boat is 30, so I just turned everything off but the solars, and now this.

So I of course am leaning towards marelon seacocks. I would much rather have a handle break off than a eaten thru seacock.
Any advice on installing these? What maintaince is needed for them.
Thanks
Bob

[GordMay]

See:

http://www.deckhardware.com.au/tech_...STALLATION.pdf

Forespar: Marine Products that Perform

http://www.forespar.com/resources2/t...hreadForms.pdf

[bobfnbw]

Thanks Gord.
I believe I will go with the Marelon through hulls by forespar. It looks like as long as you operate them on a regular basis they should do well. The risk of electrolysis is to great in my marina it seems. And I do have a grounded system and a galvanic isolator but installed by the PO so who knows if its working or not....