Raw water intake hose - debacle of the day

[drewread]

I'm working on replacing some raw water intake hoses that were called out for replacement on my pre-purchase survey. I've run into a bit of a mess on the starboard 8V-71N, surprise surprise..


Yeah.. It was that badly done.
It looks like they went from 2-1/2" Seacock (it may be 3"?) via a threaded pipe nipple coupled to a 3" hose barb, then 3" hose to another barb into another adaptor which reduces to 2-1/2" hose barb to a 2-1/2" hose to the Jabsco pump. The Jabsco pump seems to be around 2-3/4" in diameter and the hose was stretched over it. I assume they used heat to stretch that hose to get it to fit onto the Jabsco inlet.
The port side engine goes straight from the seacock to a barbed adaptor then goes into a 2-1/2" hose directly to the Jabsco pump that it is stretched to fit onto.

That seems like a lot cleaner method than this mess.


Onto the questions...
Is using a 2-1/2" hose and heat stretching it to fit over the Jabsco the correct method?
Or is it better to use 3" hose and clamp it down to the 2-3/4" Jabsco pump fitting, or is clamping the 3" hose down that much not possible ?
The barbed adaptors seem to be available to go directly from (the assumed) 2-1/2" thread to 2-1/2" or 3" hose barbs.
What thread sealant is recommended for the new pipe to barb adaptor I will need to buy to attach directly to the seacock?

I believe the strainer is a Buck Algonquin - anyone know the thread size on those?
Thanks a million - the tedious journey continues. I'm sure I'll have more threads to start this week.

 

[brettportzer]

Most of my projects are correcting these kind of “made-it-work” messes.

 

[Briankinley2004]

If I am reading this correctly I would do it like the port side. You could get the proper fittings at the seacock to go to a 2 1/2" hose barb fitting there instead of 3" and do away with that mess in between. If the seacock is 2 1/2" then a 2 1/2" x 2 1/2" hose barb should screw into it. They are about $80 per the link below

Buck Algonquin 00HN250 Bronze Pipe to Hose Adapters

00HN250 Buck Algonquin Bronze Pipe to Hose Adapters on sale now. Huge savings on Buck Algonquin hardware.

www.deepblueyachtsupply.com

 

[Briankinley2004]

Also the strainers on mine are not thru bolted. They are bedded in silicone and fastened with 3/4" stainless wood screws. I would guess somewhere in the neighborhood of 1/4x20 if they are thru bolted

 

[brettportzer]

Also, that strainer on the outside is probably screwed onto the hull over top of a regular through hull.

 

[SEVEN]

Where is the strainer?

 

[drewread]

Where is the strainer?

There Is only the strainer outside the Hull.

I'm guessing it is this one:

 

[drewread]

Any thoughts on whether or not it is better to use 3" hose or 2-1/2" hose on the 2-3/4" Jabsco raw water pump?

 

[brettportzer]

I think if it is 1/4” too big it won’t clamp down enough, I would stretch it, personally.
My raw water pipes are 2” copper, which is 2-1/8” OD. They had 2” hose on there, no problem at all.

 

[drewread]

I think if it is 1/4” too big it won’t clamp down enough, I would stretch it, personally.
My raw water pipes are 2” copper, which is 2-1/8” OD. They had 2” hose on there, no problem at all.

OK, thanks - that was my thinking as well (having never tried it...)

Apply a little heat from a heat gun to make the hose malleable, or is that a no - no?

 

[Briankinley2004]

I would try putting some liquid soap like Dawn inside the hose first before I used heat but I wouldn't leave heat off the table (in moderation). I think 2 1/2" hose is Ok. Isn't that what your other engine is running on?

 

[drewread]

I would try putting some liquid soap like Dawn inside the hose first before I used heat but I wouldn't leave heat off the table (in moderation). I think 2 1/2" hose is Ok. Isn't that what your other engine is running on?

Yes, good point.. But did you see the mess down there, lol.. Doesn't mean it was right!

 

[warrenw]

Drew, I had to get some unusual hose sizes and found New-Line in BC to be very reasonable with a good selection. If you are sure the Jabsco pump inlet barb is 2-3/4" they have the proper smooth wall wire reinforced 2-3/4" marine exhaust/water hose:

Marine Wet Exhaust & Coolant - Smooth Hardwall R1

Marine Wet Exhaust & Coolant - Smooth Hardwall R1

www.new-line.com

If you are sure the Sea Cocks ball valve outlets are 2-1/2" NPT female then you could buy a 2-1/2"NPT to 2-3/4" Hose Barb from Groco:

FF-2500 2-1/2" NPT Bronze Full Flow Hose Barb Fitting| GROCO

GROCO FF-2500 2-1/2" NPT X 2-3/4" Hose NPT Bronze Full Flow Hose Barb Fitting.

www.groco.net

2-1/2

Part Number: 973717 Item Info : UL Marine Listed FF series Shape : Hose Barb x MIP Weight: 1.420 Size : 2-1/2" X 2-3/4" 2-1/2" Npt X 2-3/4" Inner Diameter Hose Barb 973717 Description: 2-1/2NPT x 2-3/4 INNER DIAMETER HOSE BARB View Catalog Page

nassaunationalcable.com

That would reduce the number of fittings, clean up the installation and give a nice smooth water flow path to the pump.

 

[drewread]

Thanks Warren, great info.

 

[cww]

Would rather stretch a slightly smaller hose than rely on clamps alone to hold a slightly larger one in place any day of the week. Greatly reduces your chances of it popping off underway. Plus there is no point in a bigger hose when you have several smaller fittings that are restriction points in such a short run. It’s never going to pass more water than the 2.5” fitting x the pressure of the pump allows for anyway, the bigger hose doesn’t accomplish anything.

Personally I would scrap that entire setup and recreate what was there originally. These were very well designed boats. Putting aside that it’s a boat so something or another will always break regardless, I have found the amount of maintenance assache to be inversely proportional to how far you stray from the original design. The stuff that’s been the biggest pain on my boat has been where people tried to reinvent the wheel.

 

[drewread]

Thanks, I'm mid scrap.. It obviously needed to go.
If only I could get any wrenches into the area with the Seacock and gain any leverage I'd be done taking it apart. Lol.

Putting aside that it’s a boat so something or another will always break regardless,

I'm currently at the "take a look at one project and barely start it, then find 3 more projects that probably haven't been done because access is near impossible. Sigh.

 

[Captain Ralph]

May I suggest a fix for these issues that I have done before; I made fiberglass tubing with just short hose connects on each end. This removed the hose bend and so much easier to service.
You can form different sized hose ends with no metal adapters.
I have done the same for our Bertram. I can take some pictures if needed.

 

[drewread]

The saga continues, I couldn't get that threaded to threaded pipe to budge from the sea-cock last weekend with the access that is available, and thus the pipe wrench size that I could fit into that space.

I have a hair brained scheme that sees me getting the pipe wrench fitted onto this pipe and trying to rig my 1/4 ton chain fall between the pipe wrench end and the other engine's mount. That would hopefully give me enough leverage to break this loose. Somebody please talk me out of that being a good idea if you think I will be moving the other engine before I break loose that threaded fitting.

On top of that I tried to quickly measure that pipe's diameter with my caliper so I could order the correct size barbed fitting for it and I was measuring close to 2.875in in diameter. That leads me to believe that the sea-cock could potentially be 2.75in NPT, which I don't think even really exists. Could that actually be the right size? That would be diabolical.

Strike that, engineer's edge tells me that 2.5in NPT is 2.875 diameter pipe, phew! Now somebody talk me out of using my chain fall to move that wrench!
Thanks.

 

[Captain Ralph]

Do not lean on that nipple and cock if your still in the water.

Do you have vertical room for an internal pipe wrench or basin tool?

In the swamps, I use wood blocks against the frames or stringers. Then a long bar or 2by as my lever against the blocks and wrench end. Sometimes you need a third hand but beats having to purchase a one time use tool.

 

[drewread]

No, I'm on the hard. Obviously I'd be grabbing the nipple as low as possible to eliminate any levering. Maybe even rig something up to stop the nipple from becoming a lever if that was feasible, tough with it being on an angle though.

I have basin wrenches, just nowhere near 2-1/2" or 3" versions. The internal pipe wrench is interesting (a new tool to me) , but it doesn't really get me more leverage (I don't think.)

I will investigate a 2-1/2 " internal pipe wrench though. Tools are cheaper than labour, and forever.