CONTINUOUSWAVE

Can a Moeller 14-gallon or 15-gallon topside fuel tank sit directly on a fiberglass deck?

Or, should something be placed under the fuel tank to protect the fiberglass deck?

When on-deck fuel tanks were usually made of steel, Boston Whaler sold mats to be placed under the fuel tank to protect the fiberglass from being abraded by the steel fuel tank.

If you are concerned about a polyurethane fuel tank causing damage to the deck gel coat, you certainly could put a mat under the fuel tank.

The only limitation on the mat would be that it did not raise the height of the fuel tank too far and interfere with its under-seat fit or access to the filler cap.

Can they? Yes.

Should they? No.

I use and recommend Dri-Dek squares. Protects the deck, allows water and dirt to pass underneath. No fasteners required. Not expensive. Almond is a good match for Desert Tan gelcoat. White for white gelcoat.

What is the comparative hardness between the polyurethane of the fuel tank and the Dri-Dek material?

The underside of Dri-Dek is covered by dozens of small fingers which are relatively malleable. That distributes the load over multiple very small points on the boat's deck. I used it in our Sport 13 forward locker to prevent the galvanized anchor from damaging the fiberglass gel coat. I've also used it in the consoles of a Dauntless 16 and a 190 Montauk to protect the deck's gel coat from a variety of items stored within. It performed well in every application for which it was used.

Thanks [for suggesting the use of Dri-Dek to protect the fiberglass deck from abrasion by a polyethylene fuel tank]. I didn’t think of using Dri-Dek.