Hose Diameter Dilemma, Advice Needed

[thuss]

I'm replacing two cockpit drain seacocks with new bronze Groco seacocks. The hose barb adapter for the Groco seacock takes 2 1/4" ID hose. The cockpit drain tube on the other end takes 2 3/8" hose.

So the question is how to go from 2 1/4" on one end to 2 3/8" on the other end.

Would it be possible with a heat gun and some lubricant to get a 2 1/4" ID hose onto a 2 3/8" OD tube (a difference in diameter of 1/8"). I've never tried it and don't have any 2 1/4" hose on hand to test with so I thought I'd turn the collective wisdom of cruisers forum!

Unfortunately I can't find any adapters for the seacock to make it take 2 3/8" hose (which would be the ideal solution).

Thanks,
Todd

[model 10]

Heat and lube should do an 1/8" no prob. Especially if you chamfer the edge of the hose with your sharp little pocket knife.

[JPA Cate]

Another way I've seen it done is with 5200. Use the right size on the small fitting, then fit over it the larger hose, glue and clamp. Then put the larger hose on it's appropriate fitting.

Ann

[HopCar]

Are these 2" seacocks? If so replace the hose barb with a 2" bronze pipe nipple. Two inch pipe has an OD of 2-3/8". The 2-3/8" hose will be a perfect fit.

I cut the threads off the exposed end of the nipple so that they don't cut into the inside of the hose. Use a long enough nipple that you can get two clamps on and the hose will not come off the smooth side of the nipple. If clamping onto the smooth nipple bothers you, file some grooves into it.

[thuss]

Thanks for the suggestion!

Groco makes the only bronze pipe nipple I can find but it's fully threaded. All other pipe nipples I could find are red brass.

I suppose I could use epoxy on the hose side of the groco pipe nipple to smooth out the threads?

[HopCar]

THUSS, The red brass nipples sold in most marine stores, mine included, are 85-5-5-5. I think that's the same alloy that your Groco seacock is made of. At any rate, I've used them in salt water all my boating life and never had a problem with dezincification.

[Cheechako]

If you use non wire wound hose you ought to be able to get it onto 2 3/8 I would think.

[Terra Nova]

Originally Posted by HopCar

Are these 2" seacocks? If so replace the hose barb with a 2" bronze pipe nipple. Two inch pipe has an OD of 2-3/8". The 2-3/8" hose will be a perfect fit.

I cut the threads off the exposed end of the nipple...

This is your solution.

The reason to clamp the hose onto the non-threaded portion of the nipple (not a close nipple) is to be sure of creating a seal.