Expanding wet exhaust hose?

[Reefmagnet]

Well, I'm slowly but surely getting the new engine installed and hit a bit of a snag yesterday. I've got 2" exhaust hose to fit to the cast mixing elbow, but the elbow has an outside circumference of about 2 1/8". I'm using a spiral reinforced thin walled flexible hose and it just will not stretch enough to go over this larger diameter. It seems to be the wire reinforcement that is the main problem, but I'd be concerned just about any wet exhaust hose would struggle to slide over that larger diameter.



Looking for tips on how to make this fit?

[kmacdonald]

It comes in 2 1/8" size but a lot of places don't carry it. FisheriesSupply has it. If the elbow is for 2 1/8" hose you wont get 2" hose on it.

[Reefmagnet]

Originally Posted by kmacdonald

It comes in 2 1/8" size but a lot of places don't carry it. FisheriesSupply has it. If the elbow is for 2 1/8" hose you wont get 2" hose on it.

That is the most logical answer. However absolutely no one sells anything even remotely like 2 1/8" wet exhaust hose in my neck of the woods and the marine engine maker specifies 2" (actually 50mm) hose which is what the rest of the system is, so somehow it would need to be adapted to the rest of the system.

[kmacdonald]

Try liquid soap on it. Twist it in the direction that unwinds the wire reinforcement. Put it in hot water first.

[chris95040]

That’s annoying!

Have you tried a heat gun? Let it linger on low for a good long time to really soften all the rubber. Even with the wire sometimes this will let it stretch and let you ‘screw’ it on. I would plan on replacing the hose with the right size whenever you can though!

+1 on the boiling water and soap, and be careful not to slice your arm open on that g$&((;mn sharp end of the wire!

[banjoship]

I don't think 2" wire reinforced will ever go on 2 1/8".

An automotive exhaust place should be able to make up a stainless adapter pipe for you, 2 1/8" ID one end, 2" OD the other end.

Lee

[Reefmagnet]

I'm not confident that heat and hot water would expand rubber hose, especially the stuff intended for use in a wet exhaust system. And I think you're on the money, banjo. As soon as it hits the wire it stops. I've got three types of hose on hand here to experiment with and all three have internal wire reinforcement.


This is a bit of a pain in the neck. I've managed to track down a silicon reducer that I can use as a last resort that is of dubious Ebay quality, but I'd prefer to use a single piece of hose.



I'm wondering if cautious use of a tube expander works?

[Reefmagnet]

Originally Posted by kmacdonald

Try liquid soap on it. Twist it in the direction that unwinds the wire reinforcement. Put it in hot water first.

This makes some sense. Sans the hot water, I was trying this yesterday with dishwashing soap but perhaps not with too much enthusiasm with the twisting, as it is difficult because the hose has to do a 180 to clear the rear bulkhead and goes around the back of some other stuff that kind of wedges it. I was worried that if I pulled it out to be able to rotate it better I wouldn't be able to feed it back around all the obstacle it has to go through.


Definitely give this another go when back out there tomorrow.

[kmacdonald]

Soap the hose and fitting.

[Reefmagnet]

Originally Posted by kmacdonald

Soap the hose and fitting.

I did, liberally. The boat will be blowing bubbles for a while on first start.

[Exile]

Originally Posted by banjoship

I don't think 2" wire reinforced will ever go on 2 1/8".

An automotive exhaust place should be able to make up a stainless adapter pipe for you, 2 1/8" ID one end, 2" OD the other end.

Lee

Or maybe Reef will get lucky and the ID of the elbow is close enough to 2" that a SS sleeve could be used that is 2" OD on both ends.

[Scubaseas]

If soap and twist won't do it try an exhaust pipe expander. I used on my exhaust hose 20+ years ago, still fine.

[sanibel sailor]

Boil the end, use grease not soap. Be quick, it hardens quick as it cools a bit. I use a little coffee cup spiral heater to boil the water, hose end fits in cup good.

[jimbunyard]

It will usually go on, but it takes a bit of force. Chamfer the end of the fitting it's being pushed onto as much as you dare, coat the fitting fitting with liquid dishwashing soap, stick the end of the hose in boiling water for 2 minutes and then quickly shove it onto the fitting in one fell swoop. It helps to wrap a rag tightly around the hose beforehand.

If you have limited access, but are able to remove the fitting the hose slips onto to a vise, and then re-attach it with the hose assembled, that can sometimes be the quickest plan of action...

[boatpoker]

Take a grinder the the elbow.