Through Hull and Live Well Pump Install

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Seaway85

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Also there was a comment on too much water flow and damaging bait. I’m usually using mackerel that seem to like a lot of water. Any drawback to putting in a higher volume pump with a valve to lower flow when necessary? Thanks in advance.
I think you should be fine as long as the valve is on the outlet side, not the input/seacock side of the pump, but I'd be curious to hear a more experienced opinion on that from someone here. Can it damage the pump?

When I was considering building a livewell for my last boat, this article was helpful:

It recommends a pump that can recirculate your livewell's volume 1000X/day or 42X/hr, but you can probably get away with less. For reference, I'm guessing the OEM livewell on my 2300 DVCC is ~20-25 gallons, which would call for an 840-1,050GPH pump. The 700GPH Rule that was on the boat when I bought it has been enough to keep Boston mackerel happy for 6+ hours AND that's with restricted flow from a barnacle-filled pickup (which will be replaced this season).
 

Tunagi

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Few more questions, as I picked up some of the parts today.

Is it OK to use stainless steel screws on the through-hull grate to attach to exterior hull? Wondering if those screws need to be bronze as well to prevent electrolysis from dissimilar metals.

Next up - any idea how thick the hull of the boat is? I have some great material for a backing plate that is 1". Just wondering if that will be too thick, plus the thickness of the hull for the threads to have enough bite to seat properly on the seacock.

Thanks!
 
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warthog5

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On a trailer boat you can use stainless, but Bronze would be best.

Hull is aprox 1/2 to 5/8in The 1 in material will be fine.....I make a soild fiberglass piece that is 3/4in.

Now Once you get the hole thru the hull and the hole in the center of your 1in backer block....Mock it up.....Good chance the stem on the scoop will need to be shortened. Do not use the nut on the stem, except to strighten the threads after the cut is made.

You want that Seacock to be tight up aginst the block......AND you want easy access to the Seacocks handle.
 

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Tunagi

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Thanks Warthog. Superhelpful knowing the thickness of the hull.

I plan on putting it all together several times before drilling that first hole.

As always, your input is greatly appreciated!
 

dstanl01

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Thanks Warthog. Superhelpful knowing the thickness of the hull.

I plan on putting it all together several times before drilling that first hole.

As always, your input is greatly appreciated!
Did a quick sand and re-gel of the bilge. New bilge and livewell pump in place. Just need to wire and plumb. Went with the Rule 800 for the livewell. Replaced the old wash down with a jabsco hot shot 6. I’ll do an update once it’s in the water and operational. Comments/critiques appreciated.
 

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Tunagi

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Looks great! Really appreciate you sharing photos.

I was wondering on the placement in the bilge since others here recommended 6-12" from transom and 6-18' from the keel. My bilge looks to have the same design as yours, where there is a bulkhead-type piece on the floor. So going on the far edge of those recommendations would not be possible.

Have you had a chance to test out your install as of yet?

I'll post pics once I get the nerve up to start drilling holes in the bottom of my boat :)
 

Tunagi

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On a trailer boat you can use stainless, but Bronze would be best.

Hull is aprox 1/2 to 5/8in The 1 in material will be fine.....I make a soild fiberglass piece that is 3/4in.

Now Once you get the hole thru the hull and the hole in the center of your 1in backer block....Mock it up.....Good chance the stem on the scoop will need to be shortened. Do not use the nut on the stem, except to strighten the threads after the cut is made.

You want that Seacock to be tight up aginst the block......AND you want easy access to the Seacocks handle.
Warthog,

Another question. Do you eliminate the nut that comes with the pick up and use the flange of the seacock as the means secure everything?

Now that I'm starting to put the pieces together it seems I'd want everything flush....not with the 1/4" gap between the seacock and backing plate.

Pick Up Pic.jpgSeacock Pic.jpg
 

dstanl01

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Haven’t had a chance to test yet. Will let you know how it works. Hopefully this weekend.
 

warthog5

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Yes ....What GotChrist said.....You would use the nut.....if you used a ballvalve.....But No nut when using a Seacock.....:)

In your pix with the nut.....Remove the nut to establish the proper length that the scoops stem needs to be....Yes it will need to be cut, so that when tight.....The Seacock does Not bottom out on the Scoops stem.....Before the flange on the Seacock touches the backing block. But.....Before you actually make the cut on the scoops stem.....Screw that nut On the stem.......Make the cut and the nut will chase the threads back correctly.
 

Tunagi

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Thanks for the confirmation!

This site is AWESOME!!! When I finally have everything all set, I'll post some pics of the total boat project.

She's come along way since I picked her up at the beginning of March.

Thanks again Everyone!!
 

GotChrist?

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SinceWh5 mentioned ball valves be aware that thru hulls have a straight thread rather than the more common pipe thread found in hardware stores and ball valves. Groco makes a flange that has straight threads for the thru hull and the backside with pipe threads so you can install an easily replaced ball valve should that particular maintenance need arise.

Groco Bronze Tri-Flange Adapter Base (jamestowndistributors.com)

Replacing Thru-Hulls and Seacocks - Marine How To

Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Compass Marine How To at pbase.com

The Standards for Seacocks - Professional BoatBuilder Magazine (proboat.com)
 

pelagic2530

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Yes ....What GotChrist said.....You would use the nut.....if you used a ballvalve.....But No nut when using a Seacock.....:)

In your pix with the nut.....Remove the nut to establish the proper length that the scoops stem needs to be....Yes it will need to be cut, so that when tight.....The Seacock does Not bottom out on the Scoops stem.....Before the flange on the Seacock touches the backing block. But.....Before you actually make the cut on the scoops stem.....Screw that nut On the stem.......Make the cut and the nut will chase the threads back correctly.
For the record, when I did the install on my 1700, I did not have to cut the stem. I think total thickness with the mounting piece was about 1 1/2”.
 

Tunagi

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Ok....need another answer from the panel here.

Can I use a brass threaded nipple with the bronze seacock? The crew at West Marine didn't seem to have much input, other than a shoulder shrug saying "bronze and brass are pretty similar, so should be ok."
(They didn't have a plastic one so bought the only brass one they had)

But I'm not buying it. I'd imagine I'd have corrosion using that, correct?

Just having a hard time finding a plastic/pvc/nylon threaded nipple. Going to try a plumbing supply store next.....but the number of trips to get all these parts is getting pretty darn silly!
 

pelagic2530

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Ok....need another answer from the panel here.

Can I use a brass threaded nipple with the bronze seacock? The crew at West Marine didn't seem to have much input, other than a shoulder shrug saying "bronze and brass are pretty similar, so should be ok."
(They didn't have a plastic one so bought the only brass one they had)

But I'm not buying it. I'd imagine I'd have corrosion using that, correct?

Just having a hard time finding a plastic/pvc/nylon threaded nipple. Going to try a plumbing supply store next.....but the number of trips to get all these parts is getting pretty darn silly!
I would avoid mixing metals of any kind. Without getting into the depths of the ABYC corrosion tables, it's just asking for bad news when the alternative is out there.

I would check Jamestown Distributors' website. I bought all of my seacock fittings there and they have a good selection (and WAY cheaper than WM). I would avoid using a plastic fitting if at all possible.

What is the purpose of the threaded nipple? I gather you're mounting the pump remotely, as opposed to directly into the top of the seacock?
 

Tunagi

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That's what I figured. Thanks or the confirmation.

I'm going to add a strainer, as was suggested here, and need the nipple to act as male threads from the seacock to the receiving port of the strainer.
 

gregd123

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Not sure if this is correct, but I have been told never ever ever ever ever use brass in a saltwater environment, especially below deck where you will not witness the inevitable failure. This article might reinforce the point - Beware the Brass - Professional BoatBuilder Magazine
I was also told, again not sure if this is correct, but to match the materials on fittings. So, if you have a plastic female thread on your filter, use a plastic fitting. If your seacock fitting is bronze, use a bronze fitting. I used a nylon fitting, if I remember correctly, on my filter.
 

Seaway85

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Groco is widely known to make some of the best quality bronze fittings. They make bronze nipples 1/2" to 4" and Defender carries them if you can't find what you need elsewhere.
 

GotChrist?

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Never brass or plastic, only bronze or Marelon. Stainless is OK when used for head/water plumbing well above the water line.
 

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