Exhaust: Stainless vs Hose

[wufibugs]

I had drifted off the question I posed about whether to replace the 2" exhaust hose and got to thinking about using stainless for the bends which is the only place my hose is showing surface cracks. 304 stainless is cheaper than hose, but is the problem with using stainless steel exhaust pipe that this is "wet exhaust" and hose will actually long outlast the metal? I guess it's question of which lasts longer: will the hose crack where it bends before the stainless corrodes from the inside?
Not sure if this is the original hose. If so, it lasted 28 years, so what's to complain.

 

[All U Get]

Your previous picture #4 shows the date, eh? That's a nice smooth curve and loop height, I wouldn't alter it much. Down the road you might get some following seas that could back up the water, ect.

All U Get

 

[centerline]

i dont have first hand experience with the use of stainless tubing for marine exhaust, but ive read many time its not acceptable because the acids in the exhaust along with the forever wet conditions are always eating at it, and it doesnt last.....

use the hose, or for long straight runs use fiberglass exhaust tube. fiberglass exhaust tube will last forever with the exception of the seawater impeller failing and the engine overheating and it burning up due to the extreme temps of the exhaust gases.... but even then it will safely withstand much hotter temps than the rubber...

 

[woodster]

sch 40-304 SS pipe is running about 150.00 a 10 ft length i don't see how it will be any cheaper to use it instead of rubber hose @ 9.00 a foot and you haven't even put the bend in it and it is very heavy compared to rubber

 

[wufibugs]

I appreciate the comments and the widsom. Will go with hose. When I take the existing hose off I'll see if they used hard or soft.

 

[woodster]

I appreciate the comments and the widsom. Will go with hose. When I take the existing hose off I'll see if they used hard or soft.

personally i would go with hard wall in yours and mine case as you have no tight radi to make and it may go through the locker area where you store things that can move around and may shift and crush the soft wall hose collapsing and restricting the flow of your exhaust...it only costs a nickel to go first class as they say ...good luck on your selection

 

[wufibugs]

Woody, the existing hose is very stiff so I am virtually certain it is hardwall. I am sure that getting it off the mixing elbow will be unpleasant given the very cramped quarters back there. Even cutting that stuff with the wire will be a bear.

 

[All U Get]

It cuts easy with a serrated riggers knife. When you find the wire pull on the hose to expose it, then cut with side cutters. I use channel lock pliers to twist the hose end after getting the clamps off. Sometimes this breaks the seal enough to slide off.

All U Get

Maybe 21 seconds?

 

[centerline]

cutting that stuff with the wire will be a bear.

a hack saw and a pair of wire cutters will get thru it in about 20 seconds...

 

[wufibugs]

Doubt there is any way to use or even get a hack saw back there. Having gone through the the mixing elbow replacement agony on the H31, I was ready to cut an access hole to get at from the aft berth. Fortunately, I persevered without doing so. I will try the knife and maybe a monkey wrench to break the hose loose. Are the hose nipples at the muffler and transom just epoxy and fiberglass?

 

[pogo2]

I've replace the rubber hose on my M18 universal diesel, talking to exhaust mechanics stainless was not recommended for most of the reasons stated. My elbows are 1 1/4 black iron pipe fittings with 3" stubs to attach the hose with clamps. To expand the rubber hose to fit over the stubs I use a muffler expander tool ( Harbor Freight ) and a little heat from a heat gun. Also from Harbor Freight I bought a air recipicating hacksaw, its small enough to fit those most hard to fit places and it will cut the hose & wire in one move. All exposed metal fittings were wrapped with heat resistant cloth wrap(auto parts store) to keep the heat in and protect the things on the outside.

 

[Stu Jackson]

...the bends which is the only place my hose is showing surface cracks. ... If so, it lasted 28 years, so what's to complain.

--- bends - if there are cracks there, they will be all over the entire length of the hose

--- 28 years? Ha, pretty good. My hose lasted 1986 to 2012. But, this picture shows how even on a very slight curve the blow through was enough to replace the entire length.

http://c34.org/bbs/index.php/topic,6760.msg45302.html#msg45302

http://c34.org/bbs/index.php/topic,5037.msg30723.html#msg30723 mentions a coupler I bought years earlier before I replaced the entire length, only because the old end of the hose was leaking at the muffler in 2009. In retrospect, I should have replaced it all back then...

Centek makes heavy duty fiberglass fittings for this kind of hose

http://www.defender.com/product.jsp?path=-1|311|2349040|2349044&id=1656759

Beats the cost of ss any day.

 

[jibes138]

Doubt there is any way to use or even get a hack saw back there. Having gone through the the mixing elbow replacement agony on the H31, I was ready to cut an access hole to get at from the aft berth. Fortunately, I persevered without doing so. I will try the knife and maybe a monkey wrench to break the hose loose. Are the hose nipples at the muffler and transom just epoxy and fiberglass?

use an oscillating tool with a fine metal cutting blade you'll have it off in 5 seconds. Be careful not to cut the fitting.

 

[wufibugs]

Good idea, pogo, and I already have both. Same with the oscillating tool to cut the hose.
Stu, for some reason the hose in the engine compartment and back to the locker does not show any cracks. Only the stuff in the locker around the gas tank [no diesel leaks]. Since that is closed virtually all the time, can't be UV issues. I just think it has to be stress cracks from the bend.
Though slightly tempted to use the Trident Wet Exhaust Tube Connectors from Defender to avoid pulling the hose off the mixing elbow, that is, as you pointed out, a short term, and short sighted solution. With the good removal and installation ideas provided here, it should be a tolerable job to replace both hoses completely.

 

[Stu Jackson]

From other posts on the first thread I linked to above:

...since I, too, couldn't get the hose off the thru hull at the back of the boat, I started sawing away at the hose to cut it and try his approach. I was down INSIDE the lazarette (three or five times, oh joy!

), with not a whole lot of room to work in down in the hole! I refused to try going in head first, thanks to your warnings. After a few unsuccessful attempts at getting through the material, I tried pulling up on the hose and, voila, off she came! Magic!

I attribute that to the vibrations from the saw hitting the wire in the hose. Who knows??? That thru hull, thank goodness, is NOT barbed.

 

[wufibugs]

Fortunately I have the tank out, so I should be able to work on the aft bungs by going lying on my stomach head first. I have spent so much time down in that starboard locker there rewiring and reconfiguring water system, the battery locations and fuel system that I'm thinking of making it an another berth.

 

[woodster]

use an oscillating tool with a fine metal cutting blade you'll have it off in 5 seconds. Be careful not to cut the fitting.

Dremel makes a carbide blade to fit the oscillating saw its about 20 bucks at the big box store and will cut ss and black iron and it will cut through the rubber and the wire

 

[woodster]

Good idea, pogo, and I already have both. Same with the oscillating tool to cut the hose.
Stu, for some reason the hose in the engine compartment and back to the locker does not show any cracks. Only the stuff in the locker around the gas tank [no diesel leaks]. Since that is closed virtually all the time, can't be UV issues. I just think it has to be stress cracks from the bend.
Though slightly tempted to use the Trident Wet Exhaust Tube Connectors from Defender to avoid pulling the hose off the mixing elbow, that is, as you pointed out, a short term, and short sighted solution. With the good removal and installation ideas provided here, it should be a tolerable job to replace both hoses completely.

Wufi ya think maybe it just out lasted it expiration date after all its 28 years old

 

[wufibugs]

Woody, as I look more closely at the pictures previously posted, I see the date on the hose is not 1986, but 1996. Not sure why they were replaced only 11 years after the boat was built, but they are "only" 18 years old. Unless Ponce de Leon is proven right, doubtful I'll be at the helm when they go again.

 

[woodster]

Woody, as I look more closely at the pictures previously posted, I see the date on the hose is not 1986, but 1996. Not sure why they were replaced only 11 years after the boat was built, but they are "only" 18 years old. Unless Ponce de Leon is proven right, doubtful I'll be at the helm when they go again.

unless i have been misinformed you should change them at about 15 years ...i am not debating this stating what i am informed but that time always depends on usage i have seen some that were 25 years old and and still looked good