Head & Engine Thru Hull Replacement: Sizes?

NP336 · **Joined:** 16 Mar 2007 16:10 **Posts:** 143

Since I’m replacing my galley thru hull and seacock,
I have decided it may be best to also replace the thru hulls and seacock under the head sink and the engine water intake at the same time.

I’ m not sure if the head thru hull is 3/4” diamter or 1” ?
The engine water intake appears to also be either 3/4” or 1” diameter.

Can anybody confirm thru hull sizes?
Thanks in advance.

Nick
S/V Angela Mia
#336
Lake Superior

Maineiac · **Posted:** 09 Sep 2020 10:37

I thought the engine was 5/8" I.D. I'll measure tomorrow. It's the hose barb size that matters. These T37 holes are the tiniest of any boat I've ever owned.

NP336 · **Joined:** 16 Mar 2007 16:10 **Posts:** 143

Help!
Has anybody replaced thier thru hull under the head sink?
Know the thru hull size?
Thanks in advance.
Nick.

Maineiac · **Posted:** 02 Oct 2020 15:00

I'll be down to the boat tomorrow. It's the biggest seacock on the boat (same size as head outflow? But still not huge).

NOW, these things at Spartan Marine look like just the ticket to get closer to a real seacock that fits instead of the Groco valves. But cheeseum they're pricey.
https://www.spartanmarine.com/all-produ ... n-seacocks

I think these are tapered plug valves like the wilcox-crittenden I had on one of my old boats.

Maineiac · **Posted:** 06 Oct 2020 04:24

5/8 and 1.75 per hose and barrel of sink drain valve.
Engine and sink drain, respectively. I'll check the head when I get a chance.

clay123 · **Joined:** 03 Jul 2017 11:52 **Posts:** 66

My galley sink has 1.5" id. I am looking at the marelon/forespar seacocks.

Maineiac · **Posted:** 15 Oct 2020 09:16

Pricey, but these intrigue me: spartan seacocks

They look like they'll fit better than the groco or others. I had a marelon shutoff under the sink in another boat (a lot of money for a shutoff), but I never had a problem with it. I put a shutoff under the sink because a friend's boat sank due to a continual chop, pump water up the hose to the sink, pumping, pumping with no shutoff. Once it was primed, apparently it just kept going. So we got in the habit of closing the sink valve instead of digging around to close the through hull.

chrisduer · **Joined:** 26 Apr 2017 15:35 **Posts:** 23

Here is my list. Replaced w/ bronze in 2018. Hull #369

Galley Sink Drain
1-1/2”
Head Sink Drain
3/4”
Head Raw Water Intake
3/4”
Starboard Forward Blank
1”
Note: This will replace the existing depth sounder transducer. Install through hull w/ seacock and cap. May have to install 90 elbow due to height restriction under cabin sole
Engine Raw Water Intake & Sea Strainer
1”

Attachment:

File comment: Galley drain thru hull

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Attachment:

File comment: Engine Raw Water Intake

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File comment: Head thru hulls

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NP336 · **Joined:** 16 Mar 2007 16:10 **Posts:** 143

Chris,
Thanks for the confirmation on the thru hulls and photos.
This helps me a lot.
I too will be going with Groco bronze thru hull with backer
Plates.

Cheers,
Nick
S/V Angela Mia
Hull # 336
Lake Superior.

NP336 · **Joined:** 16 Mar 2007 16:10 **Posts:** 143

Chris,
Thanks for the confirmation on the thru hulls and photos.
This helps me a lot.
I too will be going with Groco bronze thru hull with backer
Plates.

Cheers,
Nick
S/V Angela Mia
Hull # 336
Lake Superior.

Tartan37.com

Head & Engine Thru Hull Replacement: Sizes?

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