I own a 22-year-old boat. The fuel tank can’t be removed and has no inspection port, so I am trying to find out how to clean the tank with the tank in place.

Jim and Loy Norris

Centerport, N.Y.

Let’s begin by dispelling any myths concerning "touchless" tank cleaning. A seriously, or even mildly, contaminated fuel tank can be properly and completely cleaned only by gaining access to its inside. Additives may help prevent some contaminant build-up. However, no additive will remove years of accumulated organic or mineral-based sediment or water. Organic contaminants include biological lifeforms both living and dead (when they die during cold weather or when you treat the tank with…