A Closer Look at Thru-Hull Fittings

A Closer Look at Thru-Hull Fittings

Don’t be fooled; this is actually a plastic thru-hull fitting with a shiny finish.

Plastic components have their place on boats, motors and trailers, and there are also places where plastic should never be used. Applications such as fuel vents, live-well intakes, and live-well drains made of plastic are cost-effective and can give many years of service.

Plastic thru-hull fittings should never be used below waterline for any reason and many boat owners are unaware of their presence because the buyer has the expectation that the manufacturer is using quality components. That is what we would like to believe, yet some manufacturers are so cost-conscious that they use the cheapest materials in all applications.  

Take a moment to inspect every fitting on your boat and look for any below-waterline intakes or discharge fittings that might be made of plastic. Change any that are plastic to bronze, and install a cut-off valve between the fitting and hose, preferably using doubled clamps.

Buyer beware; the attached photo of a thru-hull fitting appears to be chrome-plated metal but is actually plastic, removed from the bottom of a popular name-brand hull. The second photo is a Flats Cat hull where only high-quality bronze fittings are used.

The simplest things can cause the most trouble and a little investigation is a good practice.

Have a safe and fun summer!

Chris Mapp

Coastal Bend Marine
Port O’Connor, TX