When a 27-foot cabin cruiser sank at dock a few years ago, an investigation found that a hose clamp on the outdrive bellows had rusted through at a point opposite the screw, making it difficult to see. Such expensive accidents can be avoided by selecting the right clamp for the job.
The humble hose clamp serves a variety of critical functions on board most every boat on the water. Finding a supplier of marine hose clamps with a wide inventory available is as important as knowing a good mechanical shop.
Corrosion Resistant
When shopping for replacement clamps keep in mind the task at hand. Many hose clamps come in contact with fresh or salt water and so, must be corrosion resistant. That eliminates most clamps made for automotive applications. Marine clamps must be made from stainless steel classified as type 316 and produced by a reputable manufacturer.
The 316 type hose clamps are the second most common type of stainless steel clamps. This type of stainless steel has molybdenum in the alloy to make it resistant to chloride corrosion and also can be found in food service and surgical settings. The type is also a bit more expensive than non-marine clamps but definitely worth it for the corrosion resistance.
Fit for Purpose
Select the correct size hose clamp for the application. Using a clamp that is too big leaves a tail that can cut fingers or wires; too small and it may not have enough threads to stand up in a high pressure situation.
The clamp should be positioned so at least one-quarter inch of hose is visible from the clamp to the end. Also, the clamp should have its full width seated on the barb. Use double clamps for fuel fill hoses and exhaust systems.
When installing, avoid using a ratchet or other long-handled wrench. Tighten with a screw or nut driver and don’t be afraid to apply some hand torque.
Regular inspection of hose clamps will keep fluids and gasses inside where they belong.