Mission Plan for a "Weekend" project

[Dan Hill]

OK Guys and Gals here's the plan objective. Replace head and head fresh water sea-cock.

The vessel is a 1988 Hunter 28.5 on the hard close to 4 hours away. Hence the planning worries.

Whats there now? An inoperative Jabsco or maybe Sealand being fed by the OEM gate valve. Bad news I know!

What I'm installing. New PHC Raritan head fed by a proper 3/4" flanged sea-cock.

The head is pretty much straight forward in the mounting and plumbing but the sea-cock has some gray areas that I'm hoping the knowledgeable members here can help with.

THE PLAN
1. Remove inop head, fresh water hose.
2. Attempt to remove the gate valve only without disturbing the thru-hull.
3. Attach a wooden backer plate to the hull using 5200. Avoiding getting 5200 on the thru-hull somehow.
4. Thread a tri-flanged style sea-cock onto the existing thru-hull, sealed with Sikaflex 291.
5. Use SS wood screws thru the sea-cock and into the wood backer, not into the hull.
6. Install new head and route hoses accordingly.

Easy Peasy Right !!!!!!!


Here's the gray areas.

A. Is the existing thru hull long enough to catch the needed 5+ threads?
B. If I decide or have to replace the thru-hull, was the OE a flush or mushroom style?
C. Is the inner liner in the way at the thru hull? Need to trim it back?
D. Will the 5200 do the job instead of epoxy or resin?

I realize a quick look at whats there would answer most but like I stated she's 4 hours away and i didn't look at these items in the rush of hauling and winterizing after my recent purchase of the vessel.

Any and all comments or suggestions are welcome and encouraged.

Thanks

 

[Bill Roosa]

I'd not use 5200. You will never get the sucker off later. Try polysulfide (life caulk).
If you are going to take off the gate valve and add a backer plate you are pretty much at the place where you can just take the thru-hull off also. So it don't really matter (except to the wallet) if the thru-hull is long enough or which type it is. Just replace it with a longer one of the same type if you need to.
Wood screws have no place on thru-hulls. Thru bolt them from the outside. The very last thing you want is to hit something and the screws let go causing a leak.
I did this to my Catalina 30 and it was certainly something that benefits from having the first mate being around. Kinda hard to screw the nuts on AND hold the machine screw head on the outside of the boat at the same time. Solved the problem by putting sealant on the machine screw heads and installing them. Went back inside and got the nuts started and then put a socket and ratchet on the inside nut and wedged it in place so it would not fall off. Then went outside and tightened the screws. Once the screw threads where through the nuts I could grab onto the end and continue tightening the nut with a wrench.
Bring lots of paper towels.

 

[Benny17441]

Chances are you will disturb the the thru-hull or at best it may be suspect and you won't know till you launch. Like Bill says you are already there so I would rcommend you replace it. The added benefit is that you will purchase the whole set prior to getting out there and will insure that the threads on the valve and thru-hull match. The OEM gate valve is not bad news because it is a gate valve but because it is old. If this is a fresh water boat that valve may still be in good shape but there is no harm in updating. One less worry.

 

[redhead78]

Dan, google compass marine and see Maine sails excellent how to on this and many other jobs....I used it to install new engine seacock. Red

 

[Sanfelice]

Good suggestions so far. You, IMHO, are missing a critical step. Hunter did not use a vented loop in the head installation. The vast number of problems of head sinkings are due to this error. You need to place a vented loop between the bowl and the pump. In the event somebody leaves the thru hull open, the vented loop will prevent water from entering the bowl and eventually filling the boat.


http://www.defender.com/category.jsp?path=-1|51|106370|316448&id=316445

 

[Dan Hill]

Excellent advice all, thank you!

I have changed plans and will definitely replace the thru-hull also. The 5200 will only be used to adhere the wood backer block to the hull if i can manage it. The SS screws will only go thru the mounting flange of the sea-cock and thread into the backer block, not into the fiberglass hull. This has got to be better than the current gate valve which is just threaded onto the thru hull stub with no support.

Red, I started this project planning by looking at MaineSail's site. Very good info there which I will research again.

I was considering a vented loop in the head discharge to holding tank line as Peggy recommends. I didn't even think about the pump to bowl circuit and the dangers there. Thanks and I'll add that to the ever growing list:dance:.

 

[jtm]

FYI on the throw levers-

I have the H28.5 and replaced my potty about 3 yrs ago with a Jasco mini bowl manual. I replaced the 2 Gate valves and installed 2 lever throw ball valves gotten at WM ($$$). The thru hulls and their bedding looked in very good shape. I braced the thruhull and PB blaster-ed the Gate valve threads to ease the separation without turning the thruhull stem. I used teflon tape on the threads with the new valve.

The lever clearances and ergonomics of the new ball valve proved to be a problem as it was large/long enough that it impacted the space of the potty or the vanity wall or the adjacent ball valve. I didn't want to cut/shorten the lever handle( they are pretty stiff at the existing length), so I had to "pad up" the potty 1-1/2 inch with a trimmed 2x8 (or 2x6) wolmanized board ( primed and painted enamel white) to allow for the lever clearances with the bowl. I counter sunk the old potty base screws to use the same holes of the original Caulfield potty base and then sunk the Jabsco base mounts into the wolmanized board. I also had to relocate upwards the hinged teak drop seat over the potty as well as its support ledge on the vanity side.

So be forwarned about the lever clearances vs gate valve knobs.

 

[Nelsonhow]

I replaced all of the gate valves on my H-30 2 years ago with Groco Ball Valves. I used the old thru hulls because they were all in good condition.

In order to remove the old valves it was necessary to heat the valve at the point where the thru hull threads in with a plumbers torch. Otherwise the when you use a pipe wrench to twist off the old valves it 99% sure that you'll break the seal between the hull and the thru hull. You only need to heat a little just so it sizzles a bit when you put a wet rag on it. In spite of this the thru hull for the sink in the drain in the galley un seated and needed to be re-bedded.

Once the old valves were out I used 2 large wrenches and heat to remove the fittings on the other side that go into the hoses. I dide thin on the groung outside of th eboat. Also I used Teflon tape in the threads when I re-assembled to make it easier to take apart in the future.

Keep a bucket of water nearby whenever you use a flame in a boat.