I'm getting to replace several badly corroded seacocks on my Hunter 30. What is the story on Marelon fittings? The seem like a good idea to me, since they won't corrode, but the folks at my yard say they don't trust them. Is that just "traditionalism" speaking? 2) Also, are Marelon seacocks and ball valves compatable with brass through-hulls? In other words if I go to Marelon valves, must I replace the through-hulls too? 3) Anybody done this job yourself? Is it difficult? Thanks
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Seacocks
You are correct about "traditionalism". Marelon fittings are strong and do not corrode. It is not recommended to mix Marelon and metal fittings at the same thru hull location.
You are correct about "traditionalism". Marelon fittings are strong and do not corrode. It is not recommended to mix Marelon and metal fittings at the same thru hull location.
I would not use them myself.
Dean: I do not see ANY benefits of using them vs. a bronze one other than the cost. If you check out the archives you will see that there are several posts regarding these having the handle break off. Now I ask you, when does the handle usually break (when you need it the most, of course). I replaced all of my gate valves over 10 years ago and they still function very well today. WE ARE IN FRESH WATER. So everything is not equal. But I can just imagine having a hose break and then trying to shut off a seacock and have the handle break off in your hand (wow). Better have a tappered plug and a big bilge pump. Of course we know that a bronze ball valve can also jam, break or whatever, but I just feel better with something a little more substantial. Our friends have a Catalina 34 and this boat only has plastic valves. I assume that is the way Catalina delivers the boat. I have also heard that surveyors do not like them, but there is not much that they do like.
Dean: I do not see ANY benefits of using them vs. a bronze one other than the cost. If you check out the archives you will see that there are several posts regarding these having the handle break off. Now I ask you, when does the handle usually break (when you need it the most, of course). I replaced all of my gate valves over 10 years ago and they still function very well today. WE ARE IN FRESH WATER. So everything is not equal. But I can just imagine having a hose break and then trying to shut off a seacock and have the handle break off in your hand (wow). Better have a tappered plug and a big bilge pump. Of course we know that a bronze ball valve can also jam, break or whatever, but I just feel better with something a little more substantial. Our friends have a Catalina 34 and this boat only has plastic valves. I assume that is the way Catalina delivers the boat. I have also heard that surveyors do not like them, but there is not much that they do like.
Reality & Wives Tales
Marelon valves are simply superior to currently available bronze products. To start, most bronze products nowadays are not realy bronze, but dark alloys of brass, and subject heavy corrosion and seisure. Marelon is a glass filled alloy of a form of nylon. It is extremely strong and resiliant, just like our glass reinforced hulls. They are not prone to corrosion induced seisure like metal valves are. When I bought my Hunter 33 3 seasons ago all 3 existing bronze ball valves had to be replaced, and are now close to needing it again. I'm in the process of moving the galley sink drain and am using Marelon. I was curious about compatability of maralon to a bronze through hull and called Forespar. The tech there said there is no problem whatsoever mating their valves to bronze. Another wives tale trampled in the dust!!
Marelon valves are simply superior to currently available bronze products. To start, most bronze products nowadays are not realy bronze, but dark alloys of brass, and subject heavy corrosion and seisure. Marelon is a glass filled alloy of a form of nylon. It is extremely strong and resiliant, just like our glass reinforced hulls. They are not prone to corrosion induced seisure like metal valves are. When I bought my Hunter 33 3 seasons ago all 3 existing bronze ball valves had to be replaced, and are now close to needing it again. I'm in the process of moving the galley sink drain and am using Marelon. I was curious about compatability of maralon to a bronze through hull and called Forespar. The tech there said there is no problem whatsoever mating their valves to bronze. Another wives tale trampled in the dust!!
Sam, Sam.
Broken handles are not wives tales! They are broken handles. A good test of their quality is to look at ANY of the upper end boats and see what they are using brass/bronze or plastics!
Broken handles are not wives tales! They are broken handles. A good test of their quality is to look at ANY of the upper end boats and see what they are using brass/bronze or plastics!
I used them
I replaced all of my gate valves on my old 1968 Morgan with marelon seacocks and used them for 12 years with only one problem. That problem was my own fault. I snapped off a handle on a y-valve between my head, holding tank, and overboard discharge. It was early spring and the valve was frozen with a small amount of water. I forced it. I should have known better; I should have suspected that it was frozen, not just hard to turn. None of the seacocks or this y-valve were ever hard to operate. If money was no object, I would probably install bronze seacocks. However, given the cost difference, I think the marelon is good value and safe. I always operated the valves on a regular basis, always closing when I left for the week. I suppose you can disassemble and lube periodically, but I never did that. Rich
I replaced all of my gate valves on my old 1968 Morgan with marelon seacocks and used them for 12 years with only one problem. That problem was my own fault. I snapped off a handle on a y-valve between my head, holding tank, and overboard discharge. It was early spring and the valve was frozen with a small amount of water. I forced it. I should have known better; I should have suspected that it was frozen, not just hard to turn. None of the seacocks or this y-valve were ever hard to operate. If money was no object, I would probably install bronze seacocks. However, given the cost difference, I think the marelon is good value and safe. I always operated the valves on a regular basis, always closing when I left for the week. I suppose you can disassemble and lube periodically, but I never did that. Rich
Broken handles are a fact of life with Marelon
I was talking to a manufacturers rep from Forespar a few weeks ago. He claimed the handles were designed to break before exerting the force which would crack the fitting. He felt it was better to break a handle than have a broken fitting with no way to stop the water influx from a broken fitting.
I was talking to a manufacturers rep from Forespar a few weeks ago. He claimed the handles were designed to break before exerting the force which would crack the fitting. He felt it was better to break a handle than have a broken fitting with no way to stop the water influx from a broken fitting.
We're a conservative lot !!
Sailors, among boaters in general are a very conservative lot and tend to like to stick to the old and well known even if something new might be better. Look how long it took for a lot of people to accept fiberglass as a viable building material. We all know it works just fine but there are still people out there who claim it will never last, and that wood is the only material to make boats out of. Pretty much the same thing with dacron sails. And I've had handles from various metal valves break off in my hand. What does that prove, except that the valve was well stuck or the handle was corroded away? I've also had metal, bronze valves stick solid from corrosion, which glass filled nylon alloy is very unlikely to do. I'm sticking to my plan to complete my changeover to Marelon. Call me in 20 years to find out how they did.
Sailors, among boaters in general are a very conservative lot and tend to like to stick to the old and well known even if something new might be better. Look how long it took for a lot of people to accept fiberglass as a viable building material. We all know it works just fine but there are still people out there who claim it will never last, and that wood is the only material to make boats out of. Pretty much the same thing with dacron sails. And I've had handles from various metal valves break off in my hand. What does that prove, except that the valve was well stuck or the handle was corroded away? I've also had metal, bronze valves stick solid from corrosion, which glass filled nylon alloy is very unlikely to do. I'm sticking to my plan to complete my changeover to Marelon. Call me in 20 years to find out how they did.
From a Materials Viewpoint...
...my own feeling is that Marelon versus bronze is a bit of a glass-half-empty-or-half-full comparison. Marelon will never corrode on you (half full) but glass-filed nylon (which BTW is nothing like fiberglass) can be prone to brittle breakage (half empty). Vive-versa with bronze. You need to understand what you have and treat it accordingly; either can work very well. Catalina's are standard on Marelon and I don't here of Cat's sinking all over due to snapped seacocks. The only thing I would NEVER do (and I am a plastics engineer) is thread a Marelon seacok onto a bronze thru-hull fitting. Two reasons. First, even highly glass-filled plastics are much softer than metals, and stripping the Marelon threads on metal ones would be all too easy. Second, and much more important, is differences in thermal expansion. Plastics, even highly glass filled ones, still grow (heated) and shrink (cooled) much more than metals. If you thread a Marelon seacock down seal-tight onto a bronze thru-hull fitting, winter cold will shrink the Marelon hard onto that metal fitting, possibly cracking the MArelon seacock. You'll never see the crack until the water is coming in. Never thread plastic fittings onto metal ones. You might be lucky, but then again....... Carl
...my own feeling is that Marelon versus bronze is a bit of a glass-half-empty-or-half-full comparison. Marelon will never corrode on you (half full) but glass-filed nylon (which BTW is nothing like fiberglass) can be prone to brittle breakage (half empty). Vive-versa with bronze. You need to understand what you have and treat it accordingly; either can work very well. Catalina's are standard on Marelon and I don't here of Cat's sinking all over due to snapped seacocks. The only thing I would NEVER do (and I am a plastics engineer) is thread a Marelon seacok onto a bronze thru-hull fitting. Two reasons. First, even highly glass-filled plastics are much softer than metals, and stripping the Marelon threads on metal ones would be all too easy. Second, and much more important, is differences in thermal expansion. Plastics, even highly glass filled ones, still grow (heated) and shrink (cooled) much more than metals. If you thread a Marelon seacock down seal-tight onto a bronze thru-hull fitting, winter cold will shrink the Marelon hard onto that metal fitting, possibly cracking the MArelon seacock. You'll never see the crack until the water is coming in. Never thread plastic fittings onto metal ones. You might be lucky, but then again....... Carl
I just installed Marelon on my 54
Of the 12 thru-hulls, that makes 8 of them now Marelon. The new valves each come with tags emphasizing to lubricate them periodically.
Of the 12 thru-hulls, that makes 8 of them now Marelon. The new valves each come with tags emphasizing to lubricate them periodically.
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