Seacock/Through-Hull Replacement

[poiu]

Originally Posted by Dockhead

My through-hulls are unbonded, so this is unlikely. Titanium would be the perfect material for this and many other marine applications, and I think hardly more expensive than bronze. I can't imagine why titanium is not more widely used.

Have you found a titanium ball valve?

[poiu]

Originally Posted by poiu

Bronze isn't used in the EU and hasn't been for a while.

Correction to my earlier post, sloppy writing: Isn't used in valves 100% and is rarely used in through-hulls.

Even Blakes are DZR and I can't find any 100% bronze valves - body and ball anywhere in the UK. I'll probably have to go the the US and there many makers use brass balls in their valves.

[mlibkind]

Forespar and I assume others sell thru hulls and valves made from Marelon which I assume is some type of special non-metal. What do you know about this as an alternative to metal when replacing thru hulls and valves?

[mlibkind]

No need to reply to previous post; I found a good thread on Marelon.

[poiu]

Originally Posted by mlibkind

Forespar and I assume others sell thru hulls and valves made from Marelon which I assume is some type of special non-metal. What do you know about this as an alternative to metal when replacing thru hulls and valves?

I saw your cancel response message too late, I wrote the response anyway.

I've got a few. They don't impart the same confidence as bronze valves in the hand. Feels a little flimsy to me. I have read of stories of them coming apart dangerously, hopefully a design flaw that has been fixed now.

I'd be surprised if the through-hulls are anywhere near as strong as a good bronze one well installed. Mainesail has some interesting tests on his website.

I have had nylon fuel fittings fail under algae/acid attack and this doesn't help my confidence in nylon.

Also the fire argument, admittedly very unlikely, but aren't most accidents. You could conceivably get fire damage enough to rupture a hose, then for the fire to be put out enabling you to get to the bronze seacock and stop the boat sinking, whereas with a plastic ball valve that may be damaged to the point of not working.

[Dockhead]

Originally Posted by poiu

I saw your cancel response message too late, I wrote the response anyway.

I've got a few. They don't impart the same confidence as bronze valves in the hand. Feels a little flimsy to me. I have read of stories of them coming apart dangerously, hopefully a design flaw that has been fixed now.

I'd be surprised if the through-hulls are anywhere near as strong as a good bronze one well installed. Mainesail has some interesting tests on his website.

I have had nylon fuel fittings fail under algae/acid attack and this doesn't help my confidence in nylon.

Also the fire argument, admittedly very unlikely, but aren't most accidents. You could conceivably get fire damage enough to rupture a hose, then for the fire to be put out enabling you to get to the bronze seacock and stop the boat sinking, whereas with a plastic ball valve that may be damaged to the point of not working.

Marelon is nylon -- ick. Nylon absorbs water and swells. It is not as strong as metal. The Forespar ball valves jam up and break off. I don't like them at all -- no thanks.

Titanium is the ultimate material for this application. There's a company called Titan Marine which makes the through-hulls. Titanium ball valves are available from various industrial sources. I thought it was interesting after having done some Googling on the subject to find that in DRZ and bronze ball valves used for industrial purposes, titanium balls are often used. Very interesting.

I think titanium it will be -- I will gradually start researching and getting prepared for it. It's not all that expensive compared to bronze, despite the fact that this is still an oddball and therefore low volume item.

[GordMay]

Titan makes Titanium Hose Clamps, and Titanium Thru-Hulls, but no Seacock/Valves.

➥ http://www.titan-marine-hardware.com...thru-hulls.htm

➥ Hose Clamps from Titan are 100 Percent Titanium

Greg Rubin ➥ http://www.cruisersforum.com/forums/...le-105960.html

[Lojanica]

"Our apologies, but due to high demand ALL of our titanium hose clamps are temporarily Out of Stock."

Good luck with titanium both from a cost, availability, and fabrications point of view.

I made some custom parts from titanium and although I'm thrilled to death with the results it was challenging for all the reasons cited.

[Lojanica]

Try this: These are "The Best" bronze seacocks which if properly installed should last a lifetime. Spartan Marine

Seacocks (UL Approved) | Robinhood Marine Center

[Dockhead]

Originally Posted by poiu

Have you found a titanium ball valve?

Yes -- if you Google "titanium ball valve" you get a lot of hits. They seem to be used for industrial applications, probably for the same reasons we would want to use them. See for example this Taiwanese company: Titanium Ball ValvesModentic Ind.Corp.-Taiwan, stainless steel ball valves, high purity clean ball valves, stainless steel industrial ball valves, API 607 Fire Safe approved ball valves, special alloy ball valves, automation pneumatic and electric va

Really serious looking industrial valves. I have found the UK distributer and have written to them. Yateson Stainless: Ball Valve Series

These are also available in titanium: BA32 | Ball Valves - 2 Piece, Full Bore, Floating Ball, Class 300, Flanged Ends, Raised of Flat Faced | Ball Valves | Products | Shipham Valves. That's Wartsila, so will be top top quality and probably very expensive.

Here's another supplier from Taiwan: MARS VALVE CO., LTD

"Light weight - Excellent corrosion resistance

Titanium is resistant to corrosive attack by sea water or marine atmospheres, better than any other materials, It also exhibits exceptional resistance to a broad range of acids, natural waters and chemicals. Titanium ball valves present successful application for sea water and chemical plant duties."


So it seems that using titanium for ball valves is not at all a weirdo idea. They seem to be pretty widely used for industrial applications. So why shouldn't we use them?

So we can buy the through-hulls from Titan Marine, ball valves from different sources, but we still need elbows, hose bibs, hose clamps. And we have to be sure that the threads match up. But it looks to me like this would be a realistic project.

[Dockhead]

Originally Posted by Lojanica

Try this: These are "The Best" bronze seacocks which if properly installed should last a lifetime. Spartan Marine

Seacocks (UL Approved) | Robinhood Marine Center

I really prefer ball valves to cone-type seacocks -- my boat has I think 15 through-hulls below the waterline, and the annual maintenance of 15 cone-type seacocks would be just crazy.

I find that ball valves work fine as long as you cycle them fairly often. Since it is the law on my boat to shut off all the seacocks every time the boat is left overnight, my ball valves get plenty of cycling, and at 13 years old are still working perfectly. Think of the 13 years of maintenance saved already.

[Andrew Troup]

If you have to use stainless hose clips onto a hose which abuts titanium , I would be inclined to turn up some flanged bushes out of nylon , slit them, and use them (over the hose) to protect the hoseclip from the possibility of a circuit forming with the more noble titanium.

The most likely such connection would be from a trail of damp salt residue, which is quite strongly conductive over short distances if it amounts to any thickness.

But it could also happen from some metal item happening to make contact with both. Stuff can end up sloshing around in the bilge of even the tidiest of boats if it meets with a bit of action.

[Dockhead]

Originally Posted by poiu

Correction to my earlier post, sloppy writing: Isn't used in valves 100% and is rarely used in through-hulls.

Even Blakes are DZR and I can't find any 100% bronze valves - body and ball anywhere in the UK. I'll probably have to go the the US and there many makers use brass balls in their valves.

Aquafax sell real bronze ball valves:

Aquafax » Marine & Industrial Equipment

I believe the balls are stainless steel. This is what I have on my boat.

I think they are quite all right despite the modest price; mine are 13 years old and still working perfectly. Their only weakness that I can see is that the connection between handle and stem is flimsy, and you can ruin the handle pretty easily if the valve is turning hard.

Mine are neither pink nor green -- they look like pennies. The point of the bronze body, I think, is to prevent any galvanic reaction with the through-hull fitting (skin fitting), which is also real bronze.

This is the way Moodys fitted out the boat, and I think it's probably all right IF you knew how to test them and IF you knew the right replacement interval. Since I don't know that, I am guessing it's about time to replace them all just to be sure. I could do it all with the same fittings the boat came with and probably feel pretty safe for the next 10 years, or I can do it in titanium and figure the problem is solved for the rest of the life of the boat. I don't think it's going to be all that expensive in titanium, and so I'm leaning in that direction.

The problem with bronze is that, although this is a relatively good material for this application, which might last 100 years under the water line, you may still get some odd corrosion from mysterious sources, or God forbid, some stray current somehow. And then -- the valve or through hull fitting could become drastically weakened, and we would never suspect it, until it breaks off and sinks the boat. I know it's a pretty remote chance if there is no visible sign of dezincification, but I just don't like the idea of this risk. Watertight integrity of the hull just seems like an area where you just don't want to take any unnecessary chances.

[Dockhead]

Originally Posted by Andrew Troup

If you have to use stainless hose clips onto a hose which abuts titanium , I would be inclined to turn up some flanged bushes out of nylon , slit them, and use them (over the hose) to protect the hoseclip from the possibility of a circuit forming with the more noble titanium.

The most likely such connection would be from a trail of damp salt residue, which is quite strongly conductive over short distances if it amounts to any thickness.

But it could also happen from some metal item happening to make contact with both. Stuff can end up sloshing around in the bilge of even the tidiest of boats if it meets with a bit of action.

It's a good point and a good idea. But I will definitely use titanium hose clamps!!

[Lojanica]

I understand thruhulls are available in titanium and ball valves but it still isn't a seacock. True seacocks are constructed much heavier?

I think titanium is a great idea for seacocks maybe you could find a niche and make them