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Old 28-05-2024, 02:32   #1
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Through Hull Size

What is the absolute largest through hull available ?

Everywhere I look online I only see the usual suspects. Is there an xtra large thru hull available anywhere ?

This is for above the waterline to move air flow out - but is still on the side of the hull.

Is a thru hull even the right way to do something like this? I need to move as much cooling air as possible through a lazzerette - while I could open the lazerette to get hot air out its not ideal. Setting up a cross flow from port to starboard would be better - so the lazerette can stay closed while underway but the genset gets a flow of air over it.

Not sure how to go about this. I dont want the lazarette open while the genset is running due to noise. I can heavily sound insulate the lazarette to help keep noise down but that would require the lazarette to be closed to keep the noise in. So a cross flow of air from the empty life raft tunnel through the lazarette and out the side would be ideal. Another through hull in that area would not be a train smash by any means as its high above the water line.

I have already made heavy mods to this boat to suit my use case, so something like this is not outrageous.

Something else also just jumped out at me - could a snake manage to slither through a through hull ? Something to consider in my use case - we have under water cobras on the lake that are deadly - no anti-venin known for this snake bite - one bite and its lights out.. If i make the ventilation hole too big I wonder if a snake could manage to get a grip on the side of the hull and get through a thru hull? It makes me wonder why I want to be on this lake.
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Old 28-05-2024, 02:45   #2
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Re: Through Hull Size

What about a bilge blower, duct and inlet/outlet vents? 100mm can move a lot
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Old 28-05-2024, 02:45   #3
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Re: Through Hull Size

Jim Jones the power boats I regularly survey engine rooms have louvres like this on the topsides and a rectangular fiberglass dorade vent behind it. Seems to work. You could also have a couple of vents with one connected to a blower sucking hot air out and over the side. A quick google found some vents that look like 100mm diameter.
Cheers
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Old 28-05-2024, 03:11   #4
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Re: Through Hull Size

Quote:
Originally Posted by Onthewater222 View Post
What about a bilge blower, duct and inlet/outlet vents? 100mm can move a lot
There was a bilge blower setup on tis boat before I took it all out. The thing is, the bilge blower was emptying into the port lazzarette. So no use in this new setup. I have to get the hot air out of the Starboard lazarette. Out the side of the hull seems to be the most logical.
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Old 28-05-2024, 03:13   #5
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Re: Through Hull Size

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Originally Posted by Fore and Aft View Post
Jim Jones the power boats I regularly survey engine rooms have louvres like this on the topsides and a rectangular fiberglass dorade vent behind it. Seems to work. You could also have a couple of vents with one connected to a blower sucking hot air out and over the side. A quick google found some vents that look like 100mm diameter.
Cheers
Thanks for the heads up. My Goggle search powers are not working so well this morning. Need more tea.
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Old 28-05-2024, 03:17   #6
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Re: Through Hull Size

I've got a plastic one of these for my bilge blower. Lets air out but stops water coming in.
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Old 28-05-2024, 03:24   #7
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Re: Through Hull Size

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I've got a plastic one of these for my bilge blower. Lets air out but stops water coming in.
Is this mounted to the side of the hull - if so how high up is it?
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Old 28-05-2024, 03:50   #8
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Re: Through Hull Size

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Is this mounted to the side of the hull - if so how high up is it?

It is mounted on the deck. You can see part of it behind the Port sheet winch.
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Old 28-05-2024, 03:51   #9
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Re: Through Hull Size

I guess this could also work - wont stop water going in and it does have some restriction - but up high will water go in?

Restriction on air flow is key on how to do this. I dont want to do anymore welding to the hull - its so expensive

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Old 28-05-2024, 03:53   #10
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Re: Through Hull Size

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It is mounted on the deck. You can see part of it behind the Port sheet winch.
Hmm, food for thought. Thanks for the info.
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Old 28-05-2024, 03:59   #11
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Re: Through Hull Size

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Hmm, food for thought. Thanks for the info.

I've got a one way air valve. Did you see that? Here it is again.
I think that would stop a bit of water anyway


My blower is something like 130 cfm that is a huge amount of air.
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Old 28-05-2024, 04:12   #12
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Re: Through Hull Size

How much power does your blower use? 130 CFM is hard to relate too unless one is standing next to it to understand how much air that is moving.
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Old 28-05-2024, 04:24   #13
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Re: Through Hull Size

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How much power does your blower use? 130 CFM is hard to relate too unless one is standing next to it to understand how much air that is moving.

I have one installed as a bilge blower and one in the toilet (which blows into the chain locker) and is quite noisy (I think that is a plus)

Power? 12V 8A ? (I am guessing)

They are both about 3 in. diameter and would certainly suck paper up against the inlet.
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Old 28-05-2024, 05:26   #14
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Re: Through Hull Size

It is only 12V 3A 130cfm


https://www.ebay.com.au/itm/30191353...Bk9SR-7vs_L3Yw



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Old 28-05-2024, 07:20   #15
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Re: Through Hull Size

so at 24v - 1.5amps. Not that much, so yes a bilge blower would do the job
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