Yet another seacock question

[mbowser]

I'm doing an extensive refit on a Niagara 35 and I'm about to install 5 new seacocks. The boat came with a box of new Forespar marelon 849 (flanged) seacocks and I've never installed this type before. The instructions call for 4200/5200 (or equivalent sika product) on the skin fitting but to use teflon tape or thread sealant on the upper section where the actual seacock threads onto it. So, I have a few questions:
1. Is teflon tape all the same? Can I use the thread tape I've used for home applications or does it need to be 'special marine teflon tape'?
2. On several of the seacocks, there are 90 degree hose barbs seated on top and if I screw them down tight, they are not facing in the direction I need to connect the hose if I want the handle of the seacock to be remotely accessible. Can you use thread sealant or teflon tape on the hose barb to ensure a water tight connection without screwing them down as far as the can go?

Thanks

[markcouz]

Any Teflon tape should do, just add the rounds needed to get the coverage and thickness that you require.

More importantly make sure not to mix parallel thread fittings with non-parallel fittings, that is a recipe for disaster.

[markcouz]

... with sufficient tape applied for a good seal and tight fit, you can set the 90' fitting at the angle required.

[mbowser]

Originally Posted by markcouz

More importantly make sure not to mix parallel thread fittings with non-parallel fittings, that is a recipe for disaster.

Thank you, that makes me feel better.
By parallel vs non-parallel fittings I assume you mean NPT vs NPS threading? If so, all the fittings I'm using are Forespar NPS threaded.

[deblen]

Link that may help.
Suggest you avoid 5200.It is very permanent. 4200 or Sika will suffice.


https://marinehowto.com/category/plumbing/

[s/v Jedi]

Originally Posted by mbowser

I'm doing an extensive refit on a Niagara 35 and I'm about to install 5 new seacocks. The boat came with a box of new Forespar marelon 849 (flanged) seacocks and I've never installed this type before. The instructions call for 4200/5200 (or equivalent sika product) on the skin fitting but to use teflon tape or thread sealant on the upper section where the actual seacock threads onto it. So, I have a few questions:
1. Is teflon tape all the same? Can I use the thread tape I've used for home applications or does it need to be 'special marine teflon tape'?
2. On several of the seacocks, there are 90 degree hose barbs seated on top and if I screw them down tight, they are not facing in the direction I need to connect the hose if I want the handle of the seacock to be remotely accessible. Can you use thread sealant or teflon tape on the hose barb to ensure a water tight connection without screwing them down as far as the can go?

Thanks

Those are the “bad” Forespar seacocks. In sizes under 1-1/4” diameter they fail the ABYC test as demonstrated by Rod Collins in his video series.
Also, many report broken handles etc.

If you have budget I would consider buying other seacocks. If there’s no room in the budget then I can report I am testing one of these bad seacocks 3/4” diameter and after 10 years it’s still okay, no broken handle etc. It is installed in a protected location where it doesn’t get sideways loading.

I recommend the Forespar ABYC-rated models like https://www.hodgesmarine.com/fsp9040...AaAiO5EALw_wcB
or the Groco flanged adapters in bronze or the plastic TruDesign valves with load bearing collar.

[mbowser]

Yikes, I have 1 3/4", 1 1-1/4", 2 1-1/2" in the 849 flanged series. I also have 1 pro series engine flush out valve. These all came with the boat as purchased (but uninstalled).

Fortunately, none are in a location where side loading would be an issue, but I do worry about breaking the handle off though. My previous boat came with a broken handle and it was inoperable until I thoroughly greased the valve when it was out of the water and even then it was a pain (I had to use a pair of pliers on the broken handle to turn it).

Unfortunately, the Secretary of the Treasury (wife) has put a moratorium on additional spending and has told me that I have to "make do", so I will have to add a regular lube schedule to my duties to hopefully keep them moving freely.

[s/v Jedi]

Originally Posted by mbowser

Yikes, I have 1 3/4", 1 1-1/4", 2 1-1/2" in the 849 flanged series. I also have 1 pro series engine flush out valve. These all came with the boat as purchased (but uninstalled).

Fortunately, none are in a location where side loading would be an issue, but I do worry about breaking the handle off though. My previous boat came with a broken handle and it was inoperable until I thoroughly greased the valve when it was out of the water and even then it was a pain (I had to use a pair of pliers on the broken handle to turn it).

Unfortunately, the Secretary of the Treasury (wife) has put a moratorium on additional spending and has told me that I have to "make do", so I will have to add a regular lube schedule to my duties to hopefully keep them moving freely.

Unfortunately these valves don’t allow lubrication after installation. How are the old seacocks? If they are still serviceable then you could simply wait, sell what you have and buy and install better hardware next time around. The Groco flanged adapters … let me see what a 3/4” set comes to:

- theu hull fitting $18.27 https://defender.com/en_us/groco-sta...-hull-with-nut

- flanged adapter $40.99 https://defender.com/en_us/groco-ibv...langed-adapter

- full flow ball valve $30.99 https://defender.com/en_us/groco-ibv...ine-ball-valve

Total $90.-

The Forespar 849 seacock that you have now is $66.99 so the price difference isn’t shocking. I use the 849 seacocks above waterline, like for A/C cooling water discharge etc.

[mbowser]

The old seacocks have been removed and are basically piles of green metal that roughly resemble seacocks. I scratched off some of the green and found pink metal and heavy pitting throughout.
The marelon seacocks are brand new and were sitting in a box for several years before I bought the boat. I can probably justify swapping out the 3/4" with a 93 series for safety reasons, but I'm going to stay with composite instead of bronze.
Thanks for the help on this, I had no idea that there were issues with these seacocks.

[Matt Johnson]

Had the handle break off a few of those too. But each one of these was pretty old and had never been worked, so turning the handle was abnormally hard before breaking. Just open/close them often, and I'm sure you'll get a decade plus out of them.

[George_SD]

I have both - metal and marelon. Marelon is a tough material and I like that they don't rust or leach zinc. Yes, they can become hard to operate if not exercised once in a while, but that's true of all seacocks. I had to remove a Marelon throughull from a dinghy and it took me 10 minutes with a chisel and a sledgehammer before it gave.

[Flying Monkey]

I also replaced all the through hull seacocks on my boat. I took out the original, very nice and expensive to replace, fitted bronze cone seacocks. They would not close off 100% of the water flow due to metal loss.
I had 2 nice, 1 1/2 marlon seacocks installed. I took those out as well.
I experimented with different set-ups. I am partial to the groco, three piece set- up:
Groco, bronze through-hull mushroom.
New, synthetic backing plate, glassed in, with bronze threaded inserts to receive flange bolts.
Groco threaded flange.
Groco threaded ball valve.
My thinking is that rhe valve function will be the first to fail. If the through hull is tight and solid, it is much easier to change the ball valve. Hell. It could be done in the water if needed.

Some set-ups are a standard mushroom, and a flanged seacock on the inside. A new, synthetic backing plate glasses in between.

I put in one Marelon for the galley sink drain.. or maybe head drain, because I figured it would not be used much. Maybe a well lubricated, synthetic seacock is better there?

Time will tell.

But for the fit and alignment. OP!
Do a dry fit! Install the whole set up and see where the hardware needs to be to be in the right position and tight enough to not leak. Mark your locations. Install carefully. There is usually large margin for error, so you do not need to have it exact.
You do the dry fit, before you glass in the backing plate with threaded inserts, because the threaded inserts will have to line up with the flanges when the seacock is screwed on tight!

[hlev00]

I expect you realize but there is an enormous difference between 4200 and 5200. 5200 is permanent for all practical purposes. Don’t use 5200 on an seacock / skin fitting. Odd the would even suggest 5200.

[s/v Jedi]

Originally Posted by hlev00

I expect you realize but there is an enormous difference between 4200 and 5200. 5200 is permanent for all practical purposes. Don’t use 5200 on an seacock / skin fitting. Odd the would even suggest 5200.

I always use 5200. Just took off a plastic fitting for depth sounder and it took me a couple minutes with holesaw and multimaster. New one goes on with 5200 again

[stormalong]

Originally Posted by s/v Jedi

Those are the “bad” Forespar seacocks. In sizes under 1-1/4” diameter they fail the ABYC test as demonstrated by Rod Collins in his video series.
Also, many report broken handles etc.

If you have budget I would consider buying other seacocks. If there’s no room in the budget then I can report I am testing one of these bad seacocks 3/4” diameter and after 10 years it’s still okay, no broken handle etc. It is installed in a protected location where it doesn’t get sideways loading.

I recommend the Forespar ABYC-rated models like https://www.hodgesmarine.com/fsp9040...AaAiO5EALw_wcB
or the Groco flanged adapters in bronze or the plastic TruDesign valves with load bearing collar.

Can I have a link to that video? Cannot find it on howto.com.

The handle breaking problem was fixed 30+ years ago. Stop listening to "that guy" that keeps badmouthing these flanged seacocks. My 1985 boat came with the not flanged version of these seacocks. They didn't do the flanged ones back then. Other than when I first bought the boat with a couple of broken handles I have not had any problem with Marelon. I replaced those two seacocks in 1991 and those are still good today. I have been replacing the originals with flanged ones when I come across them at a good price or add a new seacock. I have 13 of them, most are now flanged. I love the fact that there is no possibility of corrosion from any cause. From the Forespar website I see that they do not claim ABYC compliance with the 849 series. I don't care. Properly installed they are as good or better than many of the maybe/maybe not bronze seacocks.

Having said that I am looking for one or two 1-1/2 inch flanged ones. So if anyone reading this has new or near new ones for sale send me a PM.


One thing I do agree with is the use of 5200 below the waterline. I like permanent. There is always a way to get them off.