Through hull seacock plumbing question

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Going with a 1-1/4" Groco seacock, and will be running the raw water for cooling through a strainer....one of the ones with the spin off clear plastic housing. To make sure I do this the best possible way, I'm looking for advice on the best material to use for the piping.

A: 1-1/4 ID marine hose, double clamped.....from seacock to strainer, and from strainer to crankshaft mounted pump?

or...

B: PVC pipe from seacock to strainer, which will be solidly mounted on a bracket, and then the marine hose from the strainer to the raw water pump, double clamped?

I haven't looked at a lot of installations, and it struck me the PVC section would make for a cleaner installation. Corrosion would be a non-issue. But is such use USCG approved I wonder?

Advice, please.
 

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Re: Through hull seacock plumbing question

I'm thinking PVC may be risky.......as fiberglass boats do flex somewhat. Perhaps the standard reinforced marine hose is the acceptable option?
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: Through hull seacock plumbing question

Not sure how the PVC would react as I've not seen that setup. Is there a financial difference and that's why you're debating between the two?
 

Georgesalmon

Lieutenant Commander
Joined
Apr 14, 2012
Messages
1,793
Re: Through hull seacock plumbing question

Wouldn't trust PVC in a boat. Its made for houses which don't move and flex and vibrate as already said.
 

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Re: Through hull seacock plumbing question

Thank you for the replies. With some sort of rigid pipe, I could have a more 'compact' set up, but the issue of vibration does raise some issues. Looks like marine hose then. Cost isn't the issue, but rather the ability to make a 90 degree turn and a 180 degree turn in the routing. I suppose I could use bronze fittings in the length of hose, to make the tight turns......although that means more hose clamps which means more locations to develop leaks. I'm trying to avoid having a large water intake hose in the bottom of the bilge making a big curve, just laying there.
 

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Re: Through hull seacock plumbing question

Wouldn't trust PVC in a boat. Its made for houses which don't move and flex and vibrate as already said.

On a side note, if you have teenagers.....the house does vibrate from music at times.....I now have another reason for them to turn it down :)
 

Ned L

Commander
Joined
Sep 17, 2008
Messages
2,268
Re: Through hull seacock plumbing question

Appropriate hose , or brass pipe (don't think you'll find bronze). (Not PVC pipe!)
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,929
Re: Through hull seacock plumbing question

I used "PVC Flex Pipe" in the Pool business all the time. Worked Great!!!
FlexPVC-Pipe-Colors.jpg
 

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Re: Through hull seacock plumbing question

I used "PVC Flex Pipe" in the Pool business all the time. Worked Great!!!
FlexPVC-Pipe-Colors.jpg

I found some 1-1/4 ID hose locally for jacuzzi tubs....seems just as tough as the marine rated stuff, but sure looks better. ($6.59 a foot, by the way.) I'm assuming the suction from a hot tub pump is a lot more than a mariune raw water pump.

Curious.....if PVC shouldn't be used below the waterline, how safe is my new Sherwood water strainer with the spin on clear bowl....the housing is plastic. The hose barbs I connect to the housing.....should I go with plastic, or try to put some stainless steel ones in without cracking the housing?
 
Top