Thru hull water intake

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Jimbob
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Thru hull water intake

Post by Jimbob » Sun Sep 04, 2016 5:46 pm

Getting ready to drill through the hull for my engine fresh water intake. What is the best placement in relation to the strut? Port or starboard? How far out from the keel?
Your thoughts will be appreciated.

Thanks jim
Jim Neeley
Building a Barrelback in Sacramento, CA
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Roberta
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Re: Thru hull water intake

Post by Roberta » Mon Sep 05, 2016 5:56 am

I placed mine (on the Torpedo) just inside the stringer and adjacent to the shaft log. I used a 1-1/2" scoop with 1-1/2" piping to a reducer for the 1-1/4" seacock. Then a 1-1/4" hose nipple was added to the seacock for the hose to the Vetus 1-1/4" strainer. Then 1-1/4" hose to the engine. Works well and cooling has been great. Also visible is the flushing "T" with shut off valve.

Roberta
Attachments
intake piping 001.JPG
Strainer 002.JPG
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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Jimbob
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Re: Thru hull water intake

Post by Jimbob » Tue Sep 06, 2016 10:53 am

Thanks Roberta!
Is that a fitting before the strainer for attaching a garden hose for running the boat out of water?

Jim
Jim Neeley
Building a Barrelback in Sacramento, CA
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Roberta
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Re: Thru hull water intake

Post by Roberta » Tue Sep 06, 2016 11:33 am

You are welcome. The flushing T is from Yachts of Stuff. I just close the seacock, open the flush shut off, connect a hose to the quick disconnect, and either flush or run water for cooling.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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Jimbob
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Re: Thru hull water intake

Post by Jimbob » Tue Sep 06, 2016 12:39 pm

Great idea! Gonna get me one.
Jim
Jim Neeley
Building a Barrelback in Sacramento, CA
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Jimbob
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Re: Thru hull water intake

Post by Jimbob » Mon Sep 19, 2016 9:56 am

So this is what I came up with.

Jim
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20160918_144409.jpg
not so sure about the hose bend.
Jim Neeley
Building a Barrelback in Sacramento, CA
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Bill Edmundson
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Re: Thru hull water intake

Post by Bill Edmundson » Mon Sep 19, 2016 10:42 am

Jim

They also make a "power" plunger that fits over the intake. You'll probably get wet. But, it works.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
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kens
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Re: Thru hull water intake

Post by kens » Mon Sep 19, 2016 6:22 pm

If your pickup is too far forward, you may have trouble getting water to the engine running on the trailer, half in-half out of the water.
I have heard it best to locate it in aft sections.
If you have any lift strakes, put it inboard of any strakes.
Oak is over rated, everything about it takes extra time; then it warps, splits or checks !!! :roll:

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Jimbob
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Re: Thru hull water intake

Post by Jimbob » Wed Sep 21, 2016 4:47 pm

Kens,

Thanks for your posting. Never even thought of the trailer interference. I looked at a couple of ski boats, and the intake is about 3" from the keel, so that's what I did. I think I will be ok. Anyway, when I have my trailer built, I will point the intake out to them, so they avoid it with the bunks. If that doesn't work, I will probably add the hose connect like Roberta did, but right now I am tired of spending money on expensive bronze pipe fittings.

Jim
Jim Neeley
Building a Barrelback in Sacramento, CA
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Brad Tucker
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Re: Thru hull water intake

Post by Brad Tucker » Fri Sep 23, 2016 2:16 pm

Looks good! You shouldn't hit a bunk there.

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Milhouse
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Re: Thru hull water intake

Post by Milhouse » Fri Aug 03, 2018 12:10 am

I have started thinking about seacocks because I didn't have one on my cooling thru-hull when I got the boat. They are strongly recommended by ABYC and common sense. I went down the rabbet hole and got scared so I came here to ask what you all do.

I was reading This article and it freaked me out because I have just the regular thru hull not a flange version. The NPS Thru-hull is also mounted very close to the stringer so that I can't get a flange mount thru hull on there without moving the thru-hull (ie. drilling a new hole and plugging this one (which also is a whole exercise in fiberglass hulls))

Option 1: (easier, faster, cheaper, less safe)
Install a NPS ball valve such as this one

Option 2:(harder, slower, pricier, safer)
Move the thru hull and install a Flanged Thru hull on a blacking block like this one in Marelon or this one in bronze


I hate to question the Queen; but Roberta are you using copper, brass and bronze together and NPT and NPS Threads and a non-flange mount thru-hull ball valve with a large lever arm (routing it through the frame probably helps/solves the lever arm situation)? I was reading This article and all of those are no-nos and are all frowned upon. So maybe I am overthinking all of this and just go with Option 1? But in my case it will be sticking straight up and have the possibility of being kicked (but the vid below shows this supporting 404lbs (shy of the 500lbs ABYC requirement).

Looks like the single hose clamps are OK below the water line per Here

Same guy that has the website linked to above posting to this This forum Interesting / scary read.

Another article on the topic

Testing video:
Here is the video

I had to learn about NPS vs NPT today too; the reason for the straight thread vs tapered ones on plumbing fittings is that since hull thickness is variable one can cut off the excess of the thru-hull fitting and not affect the thred taper (cause they are straight).
Attachments
thru-hull.jpg
My 3/4" Bronze Thru Hull, Has about a 2mm wall thickness
Jim
16' Ski Boat Restoration
17' Overnighter Sloop

I'd rather have a $h!tty meal than an $h!tty resume because a totally awesome resume will feed me steak one day - Steve Poltz

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Roberta
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Re: Thru hull water intake

Post by Roberta » Fri Aug 03, 2018 6:09 am

The thru hull pickup is bronze. Not sure of the other parts. I haven't been on salt water and don't intend to. I have been in brackish water briefly, but my system is drained and flushed often so I'm not concerned with freshwater operations. If I ever see more brackish or saltwater, I can upgrade.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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Milhouse
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Re: Thru hull water intake

Post by Milhouse » Fri Aug 03, 2018 3:20 pm

Thanks for the info Roberta; looks like I may be overthinking this a bit then.
Jim
16' Ski Boat Restoration
17' Overnighter Sloop

I'd rather have a $h!tty meal than an $h!tty resume because a totally awesome resume will feed me steak one day - Steve Poltz

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