Which Material is best for my boat tank? Avoid corrosion and compare properties between Polyethylene vs Stainless steel tanks

Polyethylene will not corrode when used for waste, stainless steel will. Stainless steel could show signs of corrosion within only a few years.

Stainless steel tanks are generally heavier than a polyethylene tank if built from a reasonable thickness of material.

Stainless CorrosionHeavily corroded weld on stainless steel tank

Stainless steel tanks are quite often more expensive than polyethylene if built by a reputable company.

Stainless steel tanks need to be earthed to the boat’s electrical system: Polyethylene tanks do not need earthing.

Contents are normally visible through a polyethylene tank: Stainless steel tanks need a sender.

A polyethylene fuel tank will almost eliminate condensation within a fuel tank. Metal tanks have to be kept filled when not in use to reduce condensation. Water in the fuel can cause engine problems.