Saltwater, particularly seawater, is full of sodium chloride, or table salt, which also happens to be a very low-pH salt that accelerates rust.
Meanwhile, traditional basket strainers are made of metal — typically some sort of steel alloy — which makes them vulnerable to rapid degradation when they come into contact with seawater.
To counteract this, many basket strainer manufacturers use a variety of corrosion-resistant metals for saltwater applications, including Monel 400, Hastelloy, and different grades of alloyed steel such as and marine-grade 316 stainless:
- Monel 400 – a nickel-copper alloy (67% Ni; 23% Cu) that is resistant to saltwater, steam, and caustic solutions
- Hastelloy – a corrosion-resistant nickel-molybdenum-chromium alloy (57% Ni; 16% Mo; 16% Cr)
- 316 Stainless Steel – steel nominally with 17% Cr and 12% Ni for increased corrosion resistance
While using these alloys certainly slow down corrosion, they never counteract it completely.
Doing so requires working with a fundamentally different material — one that is inherently immune to rust. Enter the fiberglass strainer.