Thru-Hull fitting suggestion?

N2013

Well-Known Member
Looking for suggestions on a thru-Hull fitting. I want to use an existing hole that is currently covered via an old transducer clam. Ideally, it’ll be a 90 degree thru Hull fitting (will point down), that I will then secure my intake hose to my trim tab screw. Clam is currently 2 1/4” diameter and it is a little tight for space due to trim tab actuator. Maybe a little more than a 1/2” clearance from transom. I believe I’ll need a 7/8” or 1” OD hose for my intake as the barb on the wash-down is a 3/4”. All this above the water line and I’d like to keep it that way. Anyone have an suggestions on a product to use?

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I’d just put a bracket over it to hold the hose and run it over the transom well. Then you don’t need a seacock to shut off if your pump starts leaking and spewing water into the bilge and filling the boat with water.

Not as clean looking but it eliminates one thing to have to shut off if something floods and you drop below that water line
 
Another consideration is to use a brass thru hull fitting. Tap the skin fitting side to the appropriate pipe thread you desire making sure there is enough material to be able to tap the threads into. Then thread a street elbow into the threads you just cut into the thru hull fitting and attach a suitable length of brass pipe into the street elbow, You could use a 80 degree thru hull fitting with the barbs facing upward on the inside of the transom.
Or you could again use a brass thru hull fitting with the barb on the inside and either braze or silfos a 90 degree fitting to the outside with the proper length of tubing attached
 
Any thru-hull should be either a marelon-type reinforced polymer or bronze (never brass because it's a zinc alloy) and be sealed. If your pump is below the waterline even an external line can still siphon. Always install a seacock and use it when not attending your boat.
 
Last edited:
M
Any thru-hull should be either a marelon-type reinforced polymer or bronze (never brass because it's a zinc alloy) and be sealed. If your pump is below the waterline even an external line can still siphon. Always install a seacock and use it when not attending your boat.
My seacock is frozen open. I'm assuming I have to get the cutting wheel and cut the bronze thruhull on the bottom of the hull.

There's no clearance to get wrenches downthere with any meaningful torque
 
M

My seacock is frozen open. I'm assuming I have to get the cutting wheel and cut the bronze thruhull on the bottom of the hull.

There's no clearance to get wrenches downthere with any meaningful torque
I bought a boat one year ago - same issue. Seacocks should be lubed and "excercised" occasionally but the prior owner didn't know that. I pulled the hose (boat out of the water, of course) plugged the bottom opening, used a heat gun with lots of PB Blaster sprayed inside and left in overnight. Guess what? Little by little it moved - a bit more each time till it opened and closed easily. Once a year, I lube them - some even have a zerk! Bronze seacocks are the best, serviceable and can last a lifetime. Ensure it's bonded, too.
 
I bought a boat one year ago - same issue. Seacocks should be lubed and "excercised" occasionally but the prior owner didn't know that. I pulled the hose (boat out of the water, of course) plugged the bottom opening, used a heat gun with lots of PB Blaster sprayed inside and left in overnight. Guess what? Little by little it moved - a bit more each time till it opened and closed easily. Once a year, I lube them - some even have a zerk! Bronze seacocks are the best, serviceable and can last a lifetime. Ensure it's bonded, too.
Thats good to know. My fuel tank is really close so I'll likely cut it from the bottom. Not anytime soon just one day in the off season. Zerk fitting or may put a transducer in place and run the washdown inlet through the splashwell and to the trim tab
 
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