Me 4 - Seacocks 0
- Thread starter SV_IdleHour
- Start date
I'm betting you'll sleep better when you've replaced that junk! One would think that EVERYBODY had gotten the message by now that gates valves are a serious no, no on a boat! Good job.
Yep! I got the boat from an older gent who couldn’t take take of it anymore. Priorities are: floating and drivetrain. Wait until you see the coupler lol
Got the replacements for the rotten old ones, splashing the boat ASAP as an escape pod is now on the radar. FLOAT->ENGINE->SPLASH is the new priority list, instead of picking out colors for curtains lol. Be safe out there and hello from lockdown fellas!
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,498
Nice Seacocks. I’d trash the strainer outside the hull they have a habit of getting clogged with elk grass up here or mussels. Install am in boat strainer in a place you can easily inspect and clean when needed.
Good luck with your spring tasks.
Good luck with your spring tasks.
On the other hand, external strainers keep jellyfish from being sucked into your hoses. Removed my external strainers and had to put them back the next season after a jellyfish attack. Jellyfish never made it as far as the internal strainer on my head raw water circuit. Had to reverse flush him out after returning to the dock. I suffered a complete water blockage due to a jellyfish in the hose.
Unfortunately those are not "seacocks". Unless you got the thru-hulls with "combination threads", and they don't look it, you have a thread mismatch which is not in compliance with marine safety standards. Your ball valves are NPT and your thru-hulls appear to be straight threads.
These articles may help: https://marinehowto.com/category/plumbing/
LEFT: Straght threaded thru-hull to NPT fitting RIGHT: NPT TO NPT
That’s a great article—read it a while back, I debated getting replacements or true seacocks until SHTF. My timeline and $ consideration have drastically changed. got combo threads on them all.Unfortunately those are not "seacocks". Unless you got the thru-hulls with "combination threads", and they don't look it, you have a thread mismatch which is not in compliance with marine safety standards. Your ball valves are NPT and your thru-hulls appear to be straight threads.
These articles may help: https://marinehowto.com/category/plumbing/
LEFT: Straght threaded thru-hull to NPT fitting RIGHT: NPT TO NPT
Original plywood pads were 3/4, I had 1/2 in my apartment so doubled up, any thoughts there?
I can epoxy them tonight bc install is tomorrow.
Original was not epoxied and lasted 40 years, I need them to last until I haul out after this all blows over. They are in out of the way places.
thanks for replying I appreciate it!
Original plywood pads were 3/4, I had 1/2 in my apartment so doubled up, any thoughts there?
I can epoxy them tonight bc install is tomorrow.
Original was not epoxied and lasted 40 years, I need them to last until I haul out after this all blows over. They are in out of the way places.
they ain’t pretty because 95% of my tools are at the boat (only 3 miles away) and it’s lockdown time in Hoboken.
Any tips or links to the best install video would be appreciated, I have a strategy but welcome replies!
Thanks fellas!
I can epoxy them tonight bc install is tomorrow.
Original was not epoxied and lasted 40 years, I need them to last until I haul out after this all blows over. They are in out of the way places.
they ain’t pretty because 95% of my tools are at the boat (only 3 miles away) and it’s lockdown time in Hoboken.
Any tips or links to the best install video would be appreciated, I have a strategy but welcome replies!
Thanks fellas!
Attachments
Most likely your plywood is not marine grade either. It will surely last one season but who wants to do that job twice? There are better options than plywood and gate valves. Suggest that you spend more time and money up front for a lasting and quality job. You will probably be just as stressed next season and it would it not be nice to have this job off your list?
Seems like that plywood has some voids visible between the layers, is that marine grade? I would do this once, properly, with actual seacocks, and marine grade ply or solid wood, especially if these are in out of the way places. Might take you a little more time and money today, but far less than if you wind up redoing it (or sinking). Why double the work? Save your money for champagne/lager/rye/rum when this all blows over instead of re-installing 
Edit Whoops I see you said you have matching threads! Do ball valves have the same strength rating as a seacock?
Edit Whoops I see you said you have matching threads! Do ball valves have the same strength rating as a seacock?
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Those don’t look like gate valves to me...
and he could just epoxy the plywood to seal them.
Greg
A few comments.
Marine plywood is not necessary. Marine grade plywood is marine grade primarily because of the number of plies and the lack of voids. Cabinet grade plywood is similar in there are more plies and there are no voids. More plies yields a more stable piece of wood. For the small about of plywood being used, picking up a piece of ¾" cabinet grade plywood would be cheap, look for it not in the. 4x8 sheet section of your favorite big box lumber yard, look for it in trim section. They are sometimes called hand-boards, partial sheets of various types of plywood and other sheet goods.
Glueing 2 thinner pieces of plywood to make a larger one is certainly OK, if done correctly. First, coat each side with unthickened epoxy and then use a thickened epoxy to join the two pieces. The plain epoxy will soak into the wood and provide a good bonding surface for the thickened epoxy. Epoxy bonding does not require a lot of pressure. Glue up the pieces before cutting, it will be less work.
I'm with MaineSail on the fittings. Send those ball valves back and get proper seacocks. Groco makes ball valve seacocks, a much better choice than the traditional tapered plug sea cocks. My two concerns are the mismatched threads, NPS vs NPT, it makes for a very weak leak prone joint. Second, is the mechanics. There is too much leverage with the large ball valve sitting on the thin walled mushroom fitting. The threaded part of the mushroom gets it strength from being surrounded by the backing plate and the hull as it passes through the hull and the bulk of the seacock as it is threaded into the seacock. The configuration in the photo shows a large portion of the mushroom being unsupported. This could be easily bent or cracked with unfortunate consequences ensuing. Murphy was an optimist.
Marine plywood is not necessary. Marine grade plywood is marine grade primarily because of the number of plies and the lack of voids. Cabinet grade plywood is similar in there are more plies and there are no voids. More plies yields a more stable piece of wood. For the small about of plywood being used, picking up a piece of ¾" cabinet grade plywood would be cheap, look for it not in the. 4x8 sheet section of your favorite big box lumber yard, look for it in trim section. They are sometimes called hand-boards, partial sheets of various types of plywood and other sheet goods.
Glueing 2 thinner pieces of plywood to make a larger one is certainly OK, if done correctly. First, coat each side with unthickened epoxy and then use a thickened epoxy to join the two pieces. The plain epoxy will soak into the wood and provide a good bonding surface for the thickened epoxy. Epoxy bonding does not require a lot of pressure. Glue up the pieces before cutting, it will be less work.
I'm with MaineSail on the fittings. Send those ball valves back and get proper seacocks. Groco makes ball valve seacocks, a much better choice than the traditional tapered plug sea cocks. My two concerns are the mismatched threads, NPS vs NPT, it makes for a very weak leak prone joint. Second, is the mechanics. There is too much leverage with the large ball valve sitting on the thin walled mushroom fitting. The threaded part of the mushroom gets it strength from being surrounded by the backing plate and the hull as it passes through the hull and the bulk of the seacock as it is threaded into the seacock. The configuration in the photo shows a large portion of the mushroom being unsupported. This could be easily bent or cracked with unfortunate consequences ensuing. Murphy was an optimist.