Rubber Rocks

By Tom Neale, 1/11/2007


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Using Inner tube to remove oil filter from generator
Some of my first ocean cruising experiences were in inner tubes. When we went “to the beach” when I was a little boy we’d use them as a poor man’s toy to ride the waves. The trick was to wear a T shirt so you wouldn’t get rubber burn and to stay away from that valve that always seemed to grab you in the wrong spots when your tube capsized in a wave. I still use inner tubes to keep me afloat, but not as a boat. Instead, I use them to help me keep my boats afloat.

An inner tube can be one of the handiest things you carry aboard. They take almost no room to store, and they can solve a multitude of unexpected problems. Buy a new one. It’ll be more durable and it won’t be as dirty as a used one. It may have some powder on it, but that’s not as much of a problem as old grease. It’s relatively easy to find bike tire tubes, but it’s better to have a car or truck sized tube. Keep it aboard in a handy spot. When you need to use it, you can cut pieces with scissors or a knife to suit your job. Here are a few good uses for an inner tube, but if you have one aboard, you’ll probably find more.

Many of these “fixes” are for temporary emergency repairs when nothing else will do and you need to get in. Material used by component manufacturers is generally specifically designed for the job, and you should get recommended replacements as soon as you are able. But to get safely home, you may be happy you’ve got an old fashioned inner tube.

Inner tube protects wires near engine

1. Temporary Gaskets. You can fabricate many types of gaskets. A typical example is the gasket for the cap of a sea water strainer. Often you’ll remove the cap to clean a clogged strainer basket and find that the gasket has deteriorated from compression and age. Sometimes it sticks to the rim and tears. If you’ve got a spare gasket, that’s great. But you probably don’t. Cutting one to fit from the inner tube will do the job until you can buy one made for the purpose.

2. Temporary Diaphragms. These tear unexpectedly in pumps, leaving them useless. Sometimes just a little hole in a diaphragm will render it and the pump useless or cause the pump to sling water or whatever liquid it’s moving all over the place. Low pressure cool water pumps are the most likely candidates for successful temporary fixes with a piece of inner tube. If it’s a high pressure pump the piece of tube may not last more than a few strokes. I’ve even seen a piece of inner tube used in the Bahamas for a fuel lift pump diaphragm on a diesel engine. It worked for a few hours which was long enough to get the old work boat through the reef. I wouldn’t recommend it because of the pressure, speed of pulsation, effect of the fuel on the rubber, and the consequences of a breach, but this demonstrates the versatility of inner tubes.

About Using Inner Tubes

1. Obviously inner tubes aren’t suited for everything. You’ll have to use common sense. For example, they’ll degrade rather quickly when exposed to sunlight continuously.

2. If you get a used inner tube (try to get a new one) be sure that no one has sprayed into it any of the products for temporarily fixing flat tires. They shouldn’t have because this is usually used for tubeless tires, but you never know. This product makes it difficult to use the inner tube and it may be caustic.

3. I often use a piece of rubber for the temporary insulation for exposed battery terminals or other 12 volt electrical connections. While it’s better to use insulation caps specifically made for this, if you have to make an unplanned disconnect, a piece of rubber cut from the tube will do the job temporarily. For example, if I have to pull a hot wire from a starter while replacing the starter, I usually wrap that wire in several layers of a piece of inner tube so that nothing’s bare. Of course, the hot wire should be disconnected from any power source before putting a wrench to it, but I like to wrap it also just as an extra precaution should something go wrong or someone accidentally throw a switch and reconnect it. I use electrical tape or wire tie to secure it.

4. Frequently I use a piece of inner tube for extra wire insulation. I’ll wrap wiring to protect its insulation from chafe and breach. There are many places, even on well built boats, where this is an active or potential problem. Anticipating it can save your boat. If possible, it’s best to relocate and stabilize the wire so that there is no abrasion. But sometimes when you do so you know that a shift or movement may put the wire back in harm’s way, even if you’ve carefully wire tied it. Split spiral coil made for the purpose is inexpensive and usually better, but you may find some wiring that needs protection when you can’t get this product or where it won’t fit. Again, I usually secure the piece of rubber with electrical tape or wire ties.

5. Believe it or not, a large piece of inner tube can make a great oil filter wrench. If you have to spin off a filter and you’ve left your filter wrench at home, a piece of rubber will give your hands extra traction and protect them from heat. (Take care not to burn yourself.) I also use this for other jobs where my hands need extra gripping traction. For example, new caps for the heat exchanger header tank are sometimes so tight that they’re hard to remove. If I grip them with a piece of inner tube I don’t have as much problem. I don’t mean to imply that you should remove a cap when the tank is hot. This could cause scalding water to spew out.

6. I’ve torn more clothes and gotten more cuts from hose clamps than any other cause, either on or off the boat. Now I cover many of my hose clamps with several layers of rubber, cut to fit and secured by tape or preferably wire ties. It looks a bit strange, but there’s less blood in the engine room. One problem with covering clamps or anything else is that often out of sight is out of mind. So I have to discipline myself to remove the rubber covers to inspect the clamps periodically. Hose clamps do fail, whether from rust, over tightening or vibration. Some will loosen, particularly if you’ve just put them on. The hose that they’re clamping may soften after the first tightening. Always periodically check what you cover.

Inner tube protects high pressure pipe on engine

7. Battery Mats. If you’re going to store or place a battery on a surface that’s likely to be moist, placing it on a rubber mat will result in less likelihood of slow discharge. Also, any time you’re moving a battery and need to put it down (probably because it’s too heavy and you need to take a break) it’s important to be sure that it won’t be sitting on anything that could breach the case. If there’s any question, carefully put it down a mat of several layers of cut up inner tube. This also helps to protect the deck, carpet, or whatever you’re setting it on from acid that may be on the battery case. When you’re through with the job, carefully wash off the rubber until it’s free of any acid residue and you can use it again.

And one more great thing about inner tubes? They’re not made as “marine” products. They’re still relatively cheap.

Copyright 2004-2008 Tom Neale