seacock install

[SER]

seacocks have mounting holes for through bolting but this doesn't make sense to me on a fiberglass install. 1- any impact would pull the head of the fasteners through the hull. Even with the blocking. 2-you have more exposed metal [the heads of the fasteners] with very little surface area in the water , and 3-you have addittional holes in your boat.
Am I missing something?
It seems to me a better install would be to have the the blocking bonded to the hull with fiberglass and then have the seacock mechanically fastened to that. Any opinions on this?

 

[Loren Beach]

You are right. That's one of the traditional ways. You glass the backing plate to the hull, and then put short screws (but with lots of thread area like a #12 or a quarter inch) into the block from the inside.
"Plan B" is to skip the screws and epoxy the base of the thru-hull valve to the backing plate. The newer style (OEM style) Forespar units are mean't for this. Look at the photo I posted in this forum, 10-19-02, labeled: "New Strainer & Thruhull ".
Also see another photo of a different thruhull in my short article in the Owner's Project section.

One thing to consider is that no impact from the outside of the hull will point-load the valve body on the inside. The only real threat is something like your foot or a big tool box or ?? whacking into the valve on the inside and IF it is mounted on the top of a threaded thruhull nipple, break that threaded piece right off just above the flange nut...
This is called "failing the kick test".

The standard Ericson installation is like this, unfortunately.

I replaced all 5 of my valves at once. Since the boat was already hauled out for a bottom job, replacing the valves and "doing it right" was relatively inexpensive. Boatyard labor is high, but those shipwrights are fast and the yard discounts the valves due to their ability to OEM source this stuff.

I hope this "opinion" is helpfull. OTOH, it may be worth just what you paid for it...


Fair Winds,

Loren
Olson 34 #8
Portland, OR

 

[Loren Beach]

a Picture of Two Valves Installed

After my last post, I found a photo of the two Forespar valves under the counter in the head compartment. The bases are flush on the backing plates and epoxied down. Note that these can be ordered with the discharge in any direction or straight up. The two in the photo are for the head discharge and the sink drain.

Loren in PDX

 

[SER]

I'm leaning towards bronze hdwr vs plastic. The Forespar fittings are non-conductive, non-corroding, but I belive the maintainance schedule is actually higher than traditional bronze. The fitting should be operated once a month to prevent freezing and the fitting should be relubricated every three months by closing the valve, draining the line, removing the hose clamps, and finally, removing the hose to access the ball valve. Is this correct? The monthly operation would not normally present a problem unless the boat is laid up somewhere but dismantling the hose connections at that interval seems a bit much. Do you follow this schedule?
In terms of bronze fittings, which way to go? Groco, Apollo, perko?
My E27 is 30 years old and presently has ball valves[NPT] on some of the thru hulls [NPS] . This fix is a priorty, I know, but I also have other upgrades planned so I need to shop wisely. Next thread will be on bige pump upgrades, stay tuned.

 

[Loren Beach]

More thruhull trivia

Originally posted by SER
I'm leaning towards bronze hdwr vs plastic. The Forespar fittings are non-conductive, non-corroding, but I belive the maintainance schedule is actually higher than traditional bronze. The fitting should be operated once a month to prevent freezing and the fitting should be relubricated every three months by closing the valve, draining the line, removing the hose clamps, and finally, removing the hose to access the ball valve. Is this correct? The monthly operation would not normally present a problem unless the boat is laid up somewhere but dismantling the hose connections at that interval seems a bit much. Do you follow this schedule?

My boat had "earlier production" Forespar marlon valves installed in 1988. Some were stiff-turning and I was worried that a handle might break. I replaced them all in late 2000, with the new Forespar design shown in the photos. I never took the previous ones apart or greased them and I am very sure that the p.o. never touched them, either.


I could have taken them all apart (both ends unscrew) while the boat was on the hard, but I wanted to replace them with a much stronger base-mounted, flanged thruhull. Those original valves were RC Marine valves, later renamed after purchase by forespar. I like bronze just as well, but do not want to worry about electrolysis.
One engineering upgrade is that these new valves can be taken apart from the inside -- note the 4 long bolts at the top of each in the photo.

Loren in PDX
1988 Olson 34 Far Side