Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

The watery and smelly sides of life.
Jim
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by Jim » Wed Jun 25, 2008 4:09 am

Posted: 24 Jun 2008 03:47 pm Post subject: bronze verses plastic

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Hi builders, what is the concenses of everyone when it comes to thru hull fittings, bronze or plastic. I know bronze fittings are expensive but it is an awful expensive exercise if a fitting fails. I also have read that plastic can be a problem if there is an ingress of water behind the fitting and into your plywwod laminations, swelling the timber and shearing the fitting. So what is everyone using and where
The questions are aimed at both water and electronics.
Cheers
Terryk
easy37 no25.




Hi Terry, if it is sealed properly then it won't leak regardless of the material, plastic, bronze or s/s. After cutting the hole seal the raw edge with epoxy so on the off chance it does leak it won't matter. I am using plastic. I have never had a skin fitting leak on any boat I have fitted them to.

Jim.

44c
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by 44c » Wed Jun 25, 2008 4:12 am

Well, there's plastic and there's plastic too. I think the good stuff is called marelon. I've had plastic through hulls in the old steel tub for years with no problem. In fact I think the original log through hull is as old as the boat - around 25 years.



In a wooden or glass boat, they reckon that bronze fittings will blow out and sink the boat in a lightning strike.

madaz
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by madaz » Wed Jun 25, 2008 5:23 am

I am using plastic skin fittings also Terry, for transducers etc, as Jim mentioned if you dont seal the hole properly it isnt going to matter what skin fitting you have used as the water will soak in regardless, the only exception i have is stainless ones for the toilet inlet and outlet as they have valves attached to them inside the hulls and i dont want someone to crack the fitting off trying to undo the valve. Although i am not sure if this is going to give a corrosion issue as they will be the only thing metal under the water? (except when i am motoring..)

northerncat
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by northerncat » Wed Jun 25, 2008 6:47 am

plastic apart from toilet inatke which is below waterline, all the others are an inch above the wawterline so it shouldnt matter if they leak

sean

terryk
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by terryk » Wed Jun 25, 2008 5:59 pm

Thanks guys,

I`ll put my shopping list together, don`t you just love shopping for boat bits :!: :!: That is if we ever have any money left for the event :roll:

Cheers

terryk

puremajek
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by puremajek » Wed Jun 25, 2008 8:23 pm

Terry, I pondered this for a long time too.
Well, there's plastic and there's plastic too. I think the good stuff is called marelon
I believe this to be very true. Having said this, there an Easy called Zero, that has all non-Marelon plastic below waterline skin fittings. It has been on the water for 10 years and has never had a problem with them.



I have gone Stainless Steel for all below waterline skin fittings right through to the valve, the only exception being the manufacturers plastic skin fitting for the Speed/Temp (as it is a specialty type with a removable plug type insert). There are no markings on this fitting as to its type of plastic either.



I have also beefed up the fitting hole area with an additional layer of 10mm ply and resined it very well. I added to this another 10mm 'U' shaped bracket at the valve point to prevent any movement when turning the valve. Done for similar reasons to that mentioned by Madaz above.
James
______________________________________________
http://www.diycatamaran.com
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terryk
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by terryk » Wed Jun 25, 2008 11:42 pm

Hi James, that`s a great idea, beefing up the area around the hole, a piece of say 12mm ply round eg. 100mm to 150mm dia. faired and glassed in nicely wouldn`t look to out of place, most will handle the extra wall thickness and for piece of mind a great addition.

Cheers

terryk

Whimsical
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by Whimsical » Thu Jun 26, 2008 12:47 am

I am thinking of doing some thing a little different. As the Easy's have a chined bum the same as mine it may be applicable to others here.

Having drilled the hole close to a chine, and suitably sealed the opening, I was going to glue in a piece of heavy wall PVC pipe then quite heavily glass over it to a point above the waterline. Well sealed and glassed it would take a major catastrophy to damage it and with the outlet well above the waterline a valve adds very little.



Havent decided yet, what do you all think. :shock:

The idea came from what appears to be a common practice in steel ship building.



Mike

Jim
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by Jim » Thu Jun 26, 2008 7:49 am

I think this is turning into a "how can I make this more difficult" conversation. If the hull section where the fitting is being fitted is of even thickness and a good quality sealent is used, the outside of the hull spotlessly (is that a real word?) clean and the fitting done up tight, thats it. Forget about it. Don't forget we are all building cats, so if one does leak the boat can be beached somewhere and fixed.

Jim.

terryk
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Skin Fittings, Saltwater Inlets & Seacocks (with a Poll)

Post by terryk » Thu Jun 26, 2008 11:29 pm

Thankyou Jim , we can always count on you to bring everyone back to earth :!: :!:



Cheers

terryk

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