Marelon seacock frozen

[Manateeman]

One of my mf849 marelon seacocks is frozen open. This is a full flanged seacock not a ball valve. The seacock is bolted to a 1/2 “ aluminum plate welded to the aluminum hull. It is below the waterline...a galley sink drain. Tried boiling water in the drain and towels on the seacock exterior.
We can dive on the hull and block the flow from the outside. We could construct an alum standpipe and do a quick swap from the interior. We have also seen the umbrella type plugs.
What we do not know, is the following:
What is the construction of the valve. If one uses a heat gun, what is the max temp. We have never taken this model valve apart...any one with drawings or photos ? Can it be rebuilt or polished to lessen the chance of freezing.
Since the valve almost never remains closed, we feel marine fouling growth is not a serious issue. We are perplexed as to why it occurred on this valve.
Anyone using Tef-gel . We can’t get a straight answer as to the composition of Marlube. We understand some owners have broken off the handle. Does this valve have a design issue? Lubrication...the valve is below the waterline...drain all the water above the valve...work the valve...what’s helping the sea side.
Nice if you are out of the water but I doubt marlube is a laxative for manatees.
Kindest regards.

[Ziggy]

Have you tried vegetable oil? I'm pretty sure it's safe for marelon. Since oil is lighter than water, you'd need to plug the thru hull from the outside, remove the hose and water inside the seacock, replace the hose, fill it with oil, and let it soak for a day or so.


Also, I'd contact forespar tech support: salestechsupport@forespar.com

[Manateeman]

Thank you for the reply. Forgot to post that we had contacted Forespar and they suggested marlube but will not tell us exactly what is the composition.
We regularly use vinegar and vegetable oil in our W C Skipper heads to keep them working flawlessly. They have the identical seacocks...thus the idea of veg oil , might work...will give it a shot, but the seacock is frozen open. We can calculate the volume necessary to fill the hose and even to push the oil down to the hull level. We could simply scuba dive under the hull, plug the thru hull and pull the seacock off the interior backing plate. We could do this because we are at anchor.
What if we were at sea, or somewhere that this was not an option.
My point is that these seacocks were, at the time we built this boat, the best option for an aluminum hull. Now I think I should have TIG welded a flange to 316 commercial ball valves or used heavy wall pipe to construct standpipes... all options which we can do. I just feel Forespar was being less than fully truthful.
Was there a big red tag saying “work the handle of this valve x times per year or it will freeze ?” There is no lubrication fitting on the side of the valve.
I built a glass / epoxy hull with Apollo seacocks which sat with all the seacocks shut in the water in Florida for years and while they were a bit stiff to open, each one worked. Please review prior posts from owners of marelon seacocks. Some people have no issues, yet others have snapped off the handles. As a builder, I have a lot more options available to deal with this situation. I posted in the hope that others might provide additional information or solutions which Forespar has to date, failed to address.
Kind regards.

[michaeld]

You are not alone. While others will testify in favor of marelon seacocks, I too found them inadequate. As others have reported, I had a handle snap off too. I replaced all seventeen throughulls on our boat with Groco bronze. Good luck. If you are really looking for a "lifelong" replacement, I think that you should consider Spartan.

[Breaking Waves]

Re grease, forspar instructions say you can use any non-petroleum grease (Lithium, Silicones, etc.)

”New valves come greased. Valves that have been sitting on store shelves for a long time may need more and have the handle/ball exercised. Use any non-petroleum grease (Lithium, Silicones, etc.) and no aerosols! Use a soda straw to get the grease through elbows and tailpipes and USE THE VALVES regularly to avoid marine growth from building up and seizing them. ”

Originally Posted by Manateeman

Was there a big red tag saying “work the handle of this valve x times per year or it will freeze ?” There is no lubrication fitting on the side of the valve.

Well yea, they basically say exactly that ....

”MAINTENANCE:FORESPAR® MARELON®Thru-hull/seacocksarecorrosionfreeandpro- vide great peace of mind in that regard. They are relatively maintenance free. Generally, lubrication is not required. What is required is to open and close them on a regular basis (4 times a year minimum). ”

We had these on an aluminum boat ourselves. They are not perfect. There are actually better composite ones available. But they do work if you follow the instructions.

[Manateeman]

Hi. Well where exactly do you use a soda straw to lubricate a seacock that is below the waterline. From above or below or is it necessary to dive and plug the valve opening and remove the hose? On some metal valves there is a fitting on the side where one can substitute the pipe plug with a grease fitting and actually lubricate the ball. This is not the case with this plastic seacock.
We have five 1&1/2” seacocks. All were “exercised” about the same time. One frozen. Open. So where is the marine growth given it is almost always open ? In the very small area of the Teflon seal? Is there any way to determine when the valve will fail to close. Four work then suddenly one freezes. We are not the only ones reporting this issue.
Please tell me the make of the other seacocks you mention in your reply.

[Breaking Waves]

Originally Posted by Manateeman

Please tell me the make of the other seacocks you mention in your reply.

True design using their Load Bearing Collars

If you cut open your forespar one, you would see about 1 cm edge on the ball has the grease washed off and very very small hard growth (like tiny grit) in the area making it hard to turn.

[Manateeman]

Hi. Thank you Breaking Waves. When I get this valve off, I’ll see if it’s the same area of growth but I bet it is where the ball is stuck.
I’ve seen the other valve but I feel more comfortable with bolting down the seacock...just a personal decision but thank you as maybe some readers are not aware another design exists.
I’m very discouraged because I had no idea these valves could freeze open, or that the handle could snap. It was a lot of work to fabricate, tap and weld the backing plates. We can solve the problem but it might be a nasty surprise for others who own these valves.

[Breaking Waves]

^^ I will comment that we eventually switched to (isolated) stainless valves on the aluminum boat .... we decided to get her commercial rated and none of the composite ones met the fire standard.

[Ziggy]

Originally Posted by Manateeman

[..]What if we were at sea, or somewhere that this was not an option.[...]

Right--that's why I could never bring myself to fully trust a Marelon seacock. However, they probably work just fine if regularly exercised. By the way, I find that even bronze Groco seacocks work a lot better when exercised every couple of weeks.

[Manateeman]

It’s an aluminum boat so bronze is out. One important point. We did exercised them. One failed out of five. It gave no warning. Lubricating them, if they are below the waterline, requires removing the water in the hose or greasing them underwater. There is no grease fitting or plug on the side of the seacock. The valves are not bolted together so they cannot be disassembled. It is clear the handles have snapped by other owners. What I have are seacocks which are very difficult to lubricate and fail without notice. It seems exercising them merely keeps them unfrozen by using the skeletons of marine life as an abrasive lapping paste. If your vessel is in the water, the recommended lubricant which contains Teflon, will be discharged into the surrounding water. Not exactly manatee friendly. Seriously, boatbuilders will not often admit their mistakes but I now know I should have done a lot more research on marelon seacocks and as suggested, will change to commercial stainless. It is true that in some boats they work well for years but personally, one failure is one too many for me.

[CarlF]

Forespar makes two kinds of marlon seacocks. The MF849 that you have and the OEM Series 93. Unfortunately, you have the bad kind. It is beyond me why Forespar continue to sell yours when they also have the great OEM 93's for about the same price.

The best thing to do is to haul the boat and replace with the OEM 93. I've had 8-10 of these on each of two boats over 10 years and never had one stick. I don't lubricate them. I exercise them twice a year. They move as easily as when new.

I've never heard of a handle breaking on an OEM while it's a common problem on the MF849.

The OEM 93 also passes the ABYC side loading test (the MF849 doesn't).

https://www.youtube.com/watch?v=SLvLKnzop-0

While Forespar primarily markets the OEM 93's to boatbuilders, you can find them fairly easily on the internet at most major boat supply houses.

A couple of things to know about the OEM 93. You must use the included extra thick thruhull. A regular thruhull will not fit. You will also need a slightly bigger hole through the hull to accommodate it. Finally, the water passage is a little smaller than bronze seacocks. This isn't a problem in the larger sizes but I use a 1" diameter to replace a 3/4" bronze seacock to make sure I have full flow. Finally, on most boats the seacock develops its full ABYC strength without needing backing plate or bolts - although you can use them if you prefer.

[stormalong]

I have the same seacocks. IIRC they can be disassembled. leave it bolted to the mounting plate. After you have plugged the through hull and removed the hose put a big wrench on the upper hex shaped portion and turn counterclockwise. If it comes apart you should be able to clean and lube it.

Good luck.

[flyingfin]

How many times did you try the boiling water????? Did you plug it from the outside while dumping boiling water down the throat? Did you rod out barnacles from the outside? Sometimes you must repeat boiling water 5 to 10 times, with ice water in between after the fifth attempt. Or plug from outside and fill throat with Lime Away for a week in the event it is a shell stuck in there. Patience grasshopper!

[Manateeman]

Thanks for all replies. I will try the boiling water again, this time with an outside plug. Lime away also sounds like a good idea. I also very much appreciate the information on how to take the seacock apart. One of the Forespar reps didn’t mention it.
With regard to the OEM93. I have seen the test and there is another valve with a similar wide base but both rely on the thru hull. I’m just not comfortable with no bolts . If I change to stainless, I’ll have to TIG up a custom flange / valve as most commercial valves have four bolts. This is what I should have done in the first place. One can use a flush thru hull and a tapped and welded backing plate and a valve with known strength. Would the gentleman who changed to stainless please share further details? Again, all opinions appreciated with sincere thanks.