How to Prevent Aluminum Boat and Outboard Motor Problems

Small aluminum boats and motors are quite durable but nonetheless they can develop problems over a period of time that can be annoying. Many of these problems can be resolved or prevented without taking the boat or motor in for repairs by using a methodical approach along with some patience.

Boat Seams, Rivets or Gashes That Leak

Most small aluminum boats are assembled by riveting sections of aluminum together. With prolonged or rough use it is not unusual for a leak to develop in a seam. One of the challenges in repairing a leak in an aluminum boat is to determine exactly where it is occurring. Finding an elusive leak can take patience and some detective work. Starting with the inside of the boat being dry you can launch the boat and see if you can detect the location of the leak. If you are successful locating the leak mark it with a magic marker. In some cases the leak may be located under a closed-in seat that is also riveted in place. In those cases you will have to consider patching the leak from the outside. Another approach is to cut an access hole in the seat structure so you can access the area needing repair.

Another approach in finding the location of the leak is to put the boat on a trailer and use a hose to partially fill the boat with water. With a flashlight carefully survey the seams and hull to pinpoint the leak. If the boat has good keel and side support from the trailer it should be possible to fill up to �¼ the volume. The boat owner is always responsible for using good judgement as to how much weight of water the boat can sustain when using this approach. Obviously it should be abandoned if any deformation is noticed.

Once the position of the leak is found and marked a repair method can be determined. In general it is best to apply the patch to the outside of the hull so that the force due to water pressure will tend to hold the patch to the hull. For small gashes that leak, aluminum brazing rods can be used. These can be found by doing a Google search online for ‘aluminum brazing rods’. Larger gashes are best left to professional aluminum welders in repair facilities. Fiberglass can be used for the repair a leak however the flexing of the aluminum hull may shorten the lifetime of the patch.

Various types of epoxies and compounds can also be used for the repair of leaks. Two of these are JB Weld and 3M 5200 sealant. JB Weld also makes Waterweld that can be applied under water. For any of these compounds it is critical to read and follow the directions carefully. It is always critical to start with a clean surface where you are going to make the repair.

Painting Your Boat

Most often small aluminum fishing boats are left in their original condition that is mill finish aluminum. It is preferable to apply a coat of aluminum primer on the inside and outside at roughly the water line. The inside can then be coated with a layer of rubberized non-slip paint for added safety. This will also cover any repair you may have done on the inside of the hull. Similarly the outside can be painted to keep the boat looking shipshape and to cover any leak repair that may have been done. The coat of paint on the outside will also tend to seal the seams and retard the formation of further leaks due to flexing the metal riveted seams. For good paint adherence it is critical to thoroughly clean the aluminum hull according to the aluminum primer directions.

Boat Transom Troubles

An aluminum boat typically has a transom made of a piece of plywood bolted to the stern. The primary use is to provide a rigid surface to which the outboard motor is attached. Quite often the transom on an aluminum boat is taken for granted until it no longer can serve as a secure mounting for the outboard motor. Rather then wait to react to a problem that needs repair each spring it is advisable to check your transom and determine if it is in good shape. A periodic coat of paint can make it look good if the plywood laminates are delaminating it’s time to replace it with a new one cut from marine grade or outdoor use plywood. Once cut it should be primed and painted on both sides to improve the looks and longevity.

Outboard Motor and Gas Tank

Obviously your outboard motor and gas tank should be checked prior to use in the spring. This falls more in the category of preventive maintenance then the repair of specific problems. This should include fresh gas or a mixture of fresh gas and gas that was treated with stabilizer when the boat was winterized. It’s advisable to also check the fuel line since storage at freezing temperatures can lead to brittleness and leakage over a period of time. It never hurts to put in a new fuel filter and spark plugs, properly gapped of course. During the motor winterization process the lower gearcase should have been drained and refilled. When preparing for spring and summer use it is wise to check the lower gear lube level again. In some cases the prop axle can get scored and will slowly leak oil over the winter thus depleting the amount. Check that your spare shear pin is still present. If your motor uses a battery for a starter motor make sure it is appropriately charged. Follow the outboard motor manufacturer directions on any recommended periodic maintenance.

Boating Equipment

Boat running lights, if you have them, should be checked as well as your anchor and rope. While doing this also test your air horn and check the pressure of your fire extinguisher. Inspect your life preservers/jackets to make sure they are up to par. Other equipment such as oars, and oarlocks should be checked and the oars painted, if necessary. A mobile radio or cell phone is always a good precaution to have on hand for any boating. Don’t neglect your boat trailer if you use one. Besides checking the tires for pressure of good tread, also check the wheel bearings and make sure they are packed with grease. This can prevent a costly or inconvenient repair later on during boating season. Also lube your boat trailer ratchet, ball coupling and hull rollers and check any tie downs you have to make sure they don’t need repair or replacement.

By following a list of items to check on your aluminum boat and motor you will increase the likelihood of a summer of trouble-free boating pleasure.

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