Replacing through-hulls ?

[Sven]

We're about to select a yard to haul La Petite, apply a good bottom coat, and replace the three through-hulls.

What is the collective wisdom about what brand and style of through-hulls and what material should they be made out of ?

I've seen several references to the undersized cockpit drain on the E23 and I've definitely noticed it myself, so I'm tempted to tackle that issue at the same time. Any suggestions or pointers to cockpit drain upgrades which others have carried out ?

Thanks,


-Sven

 

[gareth harris]

I dno't think there is collective wisdom on the material; I personally feel safest with bronze keeping water out, but Marelon has a very large devoted following. Bronze have advantages, but both in fact both have a good safety record in well maintained boats.
Style: A seacock is essential for protecting the through hull from shearing with a knock - even bronze can break at the thickness of the threads.
Make: Any well known brand should be fine.
I will not comment on drainage, I replaced the through hullls and hoses with the original pattern on my 35, although I know some folk have made improvements in other models.
Gareth
Freyja E35 #241 1972

 

[Loren Beach]

Now Here's a subject that comes 'round yearly!

Do a search on sea cocks on this site and you will find an absolute wealth of information, and pictures. Check the "projects" section, also.
I agree that the material is not the main criteria.
Just be sure that you have a flange mounted valve body, on a proper backing plate.
Here's a pic of the two "OEM Style" Forespar valves under the counter in our head compartment. They are epoxied to round backing plates. Stout as heck!
If you had bronze flanges bolted down to similar backing plates they would be just as strong.
Best,
Loren in Portland, OR

 

[Geoff Johnson]

I'm with Loren on the OEM Forespar seacocks. After having had two of the regular Marelon seacocks seize up on me (both were on the head outlet and they failed wihin a year or two after installation), the OEM version is the only way to go. For one thing, they can be disassembled. They may cost a little more, but the real cost is in the labor.

 

[Sven]

Good info

Thanks for the replies and the link to the writeup. Lots of common sense in one place.

Since I'm removing the Lectrasan and going with a sanipotti for the near term I'm wondering what ID throughhulls I should install for the future head and holding tank ? IOW, I'm replacing the throughhulls (and sea cocks) without fitting the plumbing to it ... I'm doing it for safety, not a head upgrade at the moment.

I also wonder if I should glass over (fill) the hole where the speed/distance log impeller used to be installed. We'll be adding instrumentation a bit later but I assume that modern impellers and sensor heads don't need a 2 (?) inch hole so we'll have to install a new one anyway ?

Thanks again,



-Sven

 

[Loren Beach]

Maybe the hole can stay.....

I just looked at the specs for the Raymarine ST60 depth meter with tranducer ----- 2 inch hole!
You can d/l the complete manual as a PDF, from their site.

Over the years, these transducers appear to have standardized to a helpful extent.

Loren

 

[u079721]

Just a note about transducers. I once had to pay to have my boat hauled mid-season just to replace the old depth trasducer that died on me. When I replaced it I made a point of going with the version of the depth transucer that is removable, and not caluked in place, so if (when?) it should fail in the future, replacement would be simple. The only downside to the removable version is that the max depth is reduced from 600 to 400 or so feet.

If you ever think you might go with Autohelm (for example) you could put in the through-hull and plug now, and add the instrument later. The plug is quite secure, and can be wired in place to prevent it from backing out. But note that the depth and speed through hulls are not the same size.

 

[Jeff Meier]

is this a good idea?

http://www.powerandmotoryacht.com/maintenance/0403hullcare/index.html

Here is a link to a good article I found on thru hull valves. Long link -- you may have to paste it into your browser.

Best,
Loren

I have been reading through these old threads because I broke the stem on a sea cock and now need to replace it. (when everyone says don't try to force open a Marelon sea cock they mean it!) I've read this article that Loren linked to above and it says it's best to haul the boat to make the repair, but if it's not possible you can temporarily seal the hole from underneath and do it in the water. No one mentions this in any thread that i have seen. Is making the repair with the boat in the water a really bad idea (emergency only) or can it be done reasonably and safely? Any thoughts / experience with this?



Jeff
1986 32-3

 

[HGSail]

I woudn't try it in the water. For me the only way to do it is out of the water. But this all depends on what the thruhull looks like (is it getting clogged or not) If it looks good, You could plug it with a wood peg and then replace the Ballvalve. If it's getting clogged, I would pull the boat and replace both the thruhull and the valve.

For me better safe than sorry.

Plus Ventura Harbor is filled with so much garbage I won't swim in there.

Davis
E29
#224
Holy Guacamole

 

[Loren Beach]

How now, stuck Valve?

FWIW, a boat builder told me that you could loosen the force/pressure on an old-style Forespar Marlon (aka RC Marine) ball valve by very carefully backing off the large "nut" on one end. That end flange "nut" (note: takes a big wrench, probably metric) is what puts pressure on the inside ball. The problem, as I understand it, is that the ball material is slightly hydroscopic, i.e. "soaks up" moisture over the years and expands slightly. Thus the binding when you turn the handle.
Just before torquing your 20-year-old handle to the breaking point, I would back off the clamps on the hose a bit, enough so that the hose could be rotated by hand. Then try to get a stubby big-end wrench on that nut and turn it a small part of a turn, while holding the other end of the valve with a matching wrench.
Usually, in some hard-to-access part of the boat, this would be quite a challenging concept...

Once the handle breaks, OTOH, looks like time to haul the boat and upgrade thru-hulls as part of this year's spring commissioning and painting.


Best of luck,
Loren in PDX
1988 O-34

 

[rssailor]

Thru hull replacement

Jeff,
If the thru hull itself is in good shape, then there is no problem with valve replacement in the water. Have done this for a customer with diver assistance and it was safe. Lube the forespar ball in the center of the valve with lanacote at every haulout and before installing a new one. Ryan