Muskrats eat rubber?

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Joined
Jul 3, 2016
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1,735
Location
Sandusky Bay
Vessel Name
Escape
Vessel Make
Mariner 37
A guy posted these photos to a Lake Erie forum I follow and explained that a muskrat entered his exhaust pipe while moored at Put In Bay and chewed that hole in the rubber sleeve in his exhaust system. That would put many boats in grave danger of sinking. Anyone familiar with that activity? What is the proper defense? Trapping or killing muskrats would only seem to delay the inevitable.
 

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Stainless steel mesh/grate on hose at transom with holes large enough not to inhibit flow, but too small for critters?
 
Interestingly, it appears that the critter used the ribbed area of that sleeve to get started. If you think about it, opening your jaw far enough to bite onto the concave surface of a hose would be very difficult but the variation at that rib or corrugated part gave it the opportunity to sink it's teeth into something.
 
Porcupines do also. I gave my son an old inflatable and he took it to his cabin in upstate NY to use on his pond.
But the porcupines had other plans. It never floated again.
 
I know common brown rats eat rubber. I had one trapped in my basement a number of years ago. He ate the rubber off of about 60 feet of power cords and extension cords before I poisoned him.

The rat turds wee actually little pieces of rubber.

pete
 
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We have muskrats in our marina. When we return to the dock I push a small fender into the exhaust outlet to keep them out. Several years ago a boat was sunk at a local yacht club when a muskrat ate through the exhaust hose.
 
Hurleymarine.com makes otter and muskrat blocking devices that install into the exhaust. We put them on our last boat, pretty easy to do. No affiliation.
 
I wish I could use those, but my exhaust comes out the side and is oblong shaped. I'll keep using the fenders. They're a lot cheaper too.
 
Good grief. Glad to learn about this the easy way. Assuming I'm not too late, that is. Thanks folks.
 
We use to have the problem on the lake. A lot of Mercruiser I/O's had bellows eaten and sunk. Also, they like styrofoam and docks would find themselves sitting lower. We set out poison. It eliminated the problem but amazingly before dying they did eat the poison and the box it was in.
 
Nasty critters, eh? Unfortunately, trapping or killing them only frees up territory for new ones to move in. Unless you had Carl Spackler or someone similarly licensed to, well, you know.
 
When I bought my boat it had rubber plugs in the exhausts. Of course I forgot to remove them one day before starting the engines, and was only able to recover one before they sank. I know there were muskrats in the marina, we saw their tracks.

Anyway, those plugs seemed like they'd be pretty inexpensive. They fit right into the exhaust outlet, so there was no tunnel for the critters to crawl into, and so (apparently) no interest in chewing. Or maybe just no way to get their teeth around it. Anyway, they must have worked, never had a muskrat gain entry or chew a plug while we were there.

I've never seen them for sale anywhere, and even now I was unable to find any using an image search. Maybe they were repurposed from some other industry.

The best I can describe them is like the white plastic stoppers they put in large mailing tubes, but made of black rubber.
 
Lived on the Ottawa River and had a pontoon boat. Muskrat crawled in the engine well and ate his way through all the electrical wires up to the helm. Battery cables too. Several neighbours got hit and one power boat was sunk when the I/O bellows were eaten.
The fix for me was to install a marine railway and haul the boat out when not in use. One neighbour used his 22 rifle. (i didn't say that)
 
At our local lake, we have had those critters eat though the plastic housing on dock float blocks.
Pesky critters and they don't seem to be afraid of anything!
 
Poison

Not sure poison is a solution.
Ogunquit ME summer 2018 or 19. Rats were a problem in the breakwaters and jetty’s from beach goers leaving lunch behind.
Solution, poison. Result, lots of Dead Sea birds.

Use it inside, ratman eats it the gets into a wall or other hidden area to croak and you’re in for a long smelly couple months.
Not to mention the danger to domestic animals.
 
When I bought my boat it had rubber plugs in the exhausts. Of course I forgot to remove them one day before starting the engines, and was only able to recover one before they sank. I know there were muskrats in the marina, we saw their tracks.

Anyway, those plugs seemed like they'd be pretty inexpensive. They fit right into the exhaust outlet, so there was no tunnel for the critters to crawl into, and so (apparently) no interest in chewing. Or maybe just no way to get their teeth around it. Anyway, they must have worked, never had a muskrat gain entry or chew a plug while we were there.

I've never seen them for sale anywhere, and even now I was unable to find any using an image search. Maybe they were repurposed from some other industry.

The best I can describe them is like the white plastic stoppers they put in large mailing tubes, but made of black rubber.

Maybe make some out of wood, they would float if you forget again. But either way I would add a small line to them to keep them from floating away.
 
Maybe make some out of wood, they would float if you forget again. But either way I would add a small line to them to keep them from floating away.

The simplest solution is always the best!

Fortunately no muskrats on salt water where I am now. I may just rig up a wooden plug on a string for my diesel heater exhaust though. No reason to keep that open to the elements all the time.
 
Once Had a Whole Family

Boat was pulled in late fall on Lake Michigan for inside storage and when I went over to work on the boat around Christmas, I found the exhaust outlet had been taped up. Checking with a guy working on a neighboring boat he told me he had done it as there was a putrid smell coming from the boat. He was right! Further discussion with the yard pointed to a muskrat that had died in the exhaust just before the boat was pulled. Then the horror stories of boats sinking came out. A little worried, I called a local plumber I knew who had a hi tech inspection camera to come over to inspect the rubber exhaust hose which was not straight. No internal damage up to the water lift muffler nor any muskrat were evident. Just wait till Spring and launch day was the consensus. Spring launch day came with no issues until I goosed the engine quite hard and Momma muskrat and three young ones blasted out in parts. You could smell the debris from 50 yards away. A Hurley was promptly installed.

Interestingly, I called my insurance to check on what coverage I may have had in the event of a sinking … vermin damage to a vessel was not covered.
 
Not covered? Yikes, that is terrible.

My marina has been surrounded by hundreds of yards of concrete sea wall for almost a hundred years. I suspect that is why so few have encountered muskrat chewing problems here. Still, I will be looking into a Hurley this winter.
 
Interestingly, I called my insurance to check on what coverage I may have had in the event of a sinking … vermin damage to a vessel was not covered.

Out of interest did your policy just exclude damage to a vessel by vermin or did it also exclude resultant damage from vermin damage. These are two different perils and while my policy also excludes vermin damage along with many others (rust oxidation etc) it does not exclude damage resulting from that damage.

So in simple terms, the damaged hose is not covered but the rest of the sunken boat, minus the hose is.

~A
 
Muskrats

I had a very similiar thing happen to me many years ago in Buffalo.While on winter layup, the underwater exhaust became a playground for a couple of rodent families. It was a Carver 41 with underwater exhausts that wasn't raised enough by the marina. With a foot of snow on the ground, they must have gotten in. When the boat was put in the water in the spring, the bilge pumps all went off. Fortunately it was still on the travel lift. The marina split the cost with me for replacing exhaust elbows. I think Hurley marine makes a grate to keep the critters out. Interestingly enough, when I called Carver to get the parts and numbers, the guy told me he was shipping all the interior soft goods for a Carver 570 that had rodents settle in for the winter and destroy the interior!!!!
 
We docked on Lake Erie for several summers and had a nest I was able to blow out with exhaust, fortunately no internal damage. After that I covered exhaust with wire when in the water, then taped up all through hulls when out of water.
 
Musk Rats

Plug your exhaust. I know of several cases of musk rats entering exhaust systems. I witnessed a boat owner crank his engine in late spring and a half dozen baby musk rats swam out. Prevent them from getting in.
 
These were installed by a PO.
The boat spent some number of years in Georgian Bay and were applied due to an “incident”.
 

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Not sure poison is a solution.
Ogunquit ME summer 2018 or 19. Rats were a problem in the breakwaters and jetty’s from beach goers leaving lunch behind.
Solution, poison. Result, lots of Dead Sea birds.

Use it inside, ratman eats it the gets into a wall or other hidden area to croak and you’re in for a long smelly couple months.
Not to mention the danger to domestic animals.

And while poison or trapping may remove a few, there are dozens or hundreds out there ready to move in to that newly vacated hunting ground. The wildlife is here to stay. Better to harden your defenses than hope to kill off every attacker.

Maybe make some out of wood, they would float if you forget again. But either way I would add a small line to them to keep them from floating away.

Simple certainly seems like an advantage, but the cost of a plug popping out while unattended is high. For me, the right answer is a more permanent grate like those commercially available.
 

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