Thru-Hull Cap

Patrick_Seattle · 23-09-2008, 22:59

As part of removing my holding tank I have a length of hose connected to the discharge thru-hull. I now want to remove this very stinky hose and cap the thru-hull until I haul out and eventually close off the thru-hull completely.

I'm browsing the www.Groco.net site and not seeing anything intended to be used as a cap neccessarily. I searched around and didn't find anything in the forums. now I'm thinking the best idea is to use a clean length of hose, cap it and then attach that hose to the closed thru-hull with 2 clamps on through hull and the plugged ends of course.

Is there a better alternative?

Thanks,
-p

Liberty28 · 24-09-2008, 04:29

Sounds like a plan to me. I personally don't care for holes in the hull, but since you've got one already sitting there (albeit decommissioned), you might just let it be for a while just in case the need arises someday for a new through-hull. At least you won't need to cut a new one. Of course, if the need hasn't arisen after a period of time, then glass it over permanently.

Joli · 24-09-2008, 05:01

PVC threaded plugs in the seacock, works a treat.

**GordMay** · 24-09-2008, 05:26

Thru-Hull fittings generally have un-tapered NPS (straight) male threads, whereas Seacocks (valves) generally have NPT (tapered) female threads.
The cap or plug you select will have to match the mating fitting.

See the mainecruising Seacock Primer,
specifically
“Mismatched Threads”:
Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Maine Sailing at pbase.com

and:
American National Pipe - NPT/NPS:
American National Pipe - NPT/NPS | Pipe and Hose

Talbot · 24-09-2008, 09:25

Begs the question of why you would want to remove a holding tank at a time when more and more people are wanting to have them fitted.

Patrick_Seattle · 24-09-2008, 10:49

Thanks Gord and Joli. I'll check my threading and look for that screw plug.

As to why I'm pulling out the tank. I am putting in a composting head,
more on that here: S/V Deep Playa - Pearson 424 : We're looking for the trash fence

Thanks again for the help!
-p

Patrick_Seattle · 26-09-2008, 21:43

I found a bronze cap and I was working towards getting it in but my seacock leaked enough that I decided to haul out. I'm hanging I'm the sling tonight. Everything is ready to go back together. My only question is do I need something on the threads (like plumbers tape for nautical fittings) or do I just thread it on tight and I'm good?

Thanks!
-P

**David M** · 26-09-2008, 21:45

Put a little teflon tape on it.

Patrick_Seattle · 27-09-2008, 00:42

Thanks again !
I go back in the water in the morning.

I was very happy (and surprised) I was able to get the 20+ year old 90 degree bend off the seacock, but with a nice large pipe wrench and some elbow grease it came off pretty easily. Hardly any swearing at all! :-)

-p

23-09-2008, 22:59	#1
Patrick_Seattle Registered User Join Date: Feb 2008 Location: Seattle, WA Boat: Pearson 424 - S/V Deep Playa Posts: 28	Thru-Hull Cap As part of removing my holding tank I have a length of hose connected to the discharge thru-hull. I now want to remove this very stinky hose and cap the thru-hull until I haul out and eventually close off the thru-hull completely. I'm browsing the www.Groco.net site and not seeing anything intended to be used as a cap neccessarily. I searched around and didn't find anything in the forums. now I'm thinking the best idea is to use a clean length of hose, cap it and then attach that hose to the closed thru-hull with 2 clamps on through hull and the plugged ends of course. Is there a better alternative? Thanks, -p __________________ ----------------------------- s/v Deep Playa \| Pearson 424 #152 \| http://www.DeepPlaya.com Patrick's Sailing Blog \| http://www.shipsrecord.com/blogs/patrick

24-09-2008, 05:26	#4
GordMay Administrator Site Administrator Join Date: Mar 2003 Location: Thunder Bay, Ontario - 48-29N x 89-20W Boat: C.L.O.D. (Cruiser Living On Dirt) Posts: 9,316 Images: 230	Thru-Hull fittings generally have un-tapered NPS (straight) male threads, whereas Seacocks (valves) generally have NPT (tapered) female threads. The cap or plug you select will have to match the mating fitting. See the mainecruising Seacock Primer, specifically “Mismatched Threads”: Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Maine Sailing at pbase.com and: American National Pipe - NPT/NPS: American National Pipe - NPT/NPS \| Pipe and Hose __________________ Gord May ~~_/)_~~ (Gord & Maggie - "Southbound") "If you didn't have time/$ to do it right in the first place, when will you get the time/$ to fix it?" Last edited by GordMay; 24-09-2008 at 10:52.

24-09-2008, 09:25	#5
Talbot Registered User Join Date: Jun 2004 Location: Stavanger, Norway Boat: Last boat was a Catalac 9m Hi-Jude Posts: 2,026 Images: 23	Begs the question of why you would want to remove a holding tank at a time when more and more people are wanting to have them fitted. __________________ "Be wary of strong drink. It can make you shoot at tax collectors - and miss." Robert A Heinlein

24-09-2008, 10:49	#6
Patrick_Seattle Registered User Join Date: Feb 2008 Location: Seattle, WA Boat: Pearson 424 - S/V Deep Playa Posts: 28	Thanks Gord and Joli. I'll check my threading and look for that screw plug. As to why I'm pulling out the tank. I am putting in a composting head, more on that here: S/V Deep Playa - Pearson 424 : We're looking for the trash fence Thanks again for the help! -p __________________ ----------------------------- s/v Deep Playa \| Pearson 424 #152 \| http://www.DeepPlaya.com Patrick's Sailing Blog \| http://www.shipsrecord.com/blogs/patrick

26-09-2008, 21:43	#7
Patrick_Seattle Registered User Join Date: Feb 2008 Location: Seattle, WA Boat: Pearson 424 - S/V Deep Playa Posts: 28	I found a bronze cap and I was working towards getting it in but my seacock leaked enough that I decided to haul out. I'm hanging I'm the sling tonight. Everything is ready to go back together. My only question is do I need something on the threads (like plumbers tape for nautical fittings) or do I just thread it on tight and I'm good? Thanks! -P __________________ ----------------------------- s/v Deep Playa \| Pearson 424 #152 \| http://www.DeepPlaya.com Patrick's Sailing Blog \| http://www.shipsrecord.com/blogs/patrick

24-09-2008, 04:29	#2
Liberty28 Registered User Join Date: Dec 2007 Location: Chippewa Falls, WI/ Florida Keys Boat: Liberty 28 Custom Cutter - "Native Dancer" Posts: 157	Sounds like a plan to me. I personally don't care for holes in the hull, but since you've got one already sitting there (albeit decommissioned), you might just let it be for a while just in case the need arises someday for a new through-hull. At least you won't need to cut a new one. Of course, if the need hasn't arisen after a period of time, then glass it over permanently.

24-09-2008, 05:01	#3
Joli Registered User Join Date: Nov 2005 Location: Ohio Posts: 1,191 Images: 6	PVC threaded plugs in the seacock, works a treat.

26-09-2008, 21:45	#8
David M Moderator Site Helper Join Date: Sep 2007 Location: San Francisco Bay Posts: 2,687	Put a little teflon tape on it. __________________ David Whenever I find myself growing grim...whenever it is a damp, drizzly November in my soul...I account it high time to get to sea as soon as I can. -HERMAN MELVILLE, Moby Dick

27-09-2008, 00:42	#9
Patrick_Seattle Registered User Join Date: Feb 2008 Location: Seattle, WA Boat: Pearson 424 - S/V Deep Playa Posts: 28	Thanks again ! I go back in the water in the morning. I was very happy (and surprised) I was able to get the 20+ year old 90 degree bend off the seacock, but with a nice large pipe wrench and some elbow grease it came off pretty easily. Hardly any swearing at all! :-) -p __________________ ----------------------------- s/v Deep Playa \| Pearson 424 #152 \| http://www.DeepPlaya.com Patrick's Sailing Blog \| http://www.shipsrecord.com/blogs/patrick

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