What is the best way to clean off the double skinning on my pontoons? The smooth part of the pontoon is fairly easy to clean but the rough double skin is difficult. I figured using a nylon brush in a drill will work, but what about the solvent / cleaning agent? Will ammonia (used only for a short period then rinsed) work or is there something better?
I can't answer about the texture you have the difficulty with - but there are lots of posts here on cleaning tubes (I assume hypalon?). First step would be what is known as "TFR or traffic film remover" its a sodium hydroxide (caustic) solution with some other stuff added. You want proper stuff not "consumer" grade - i.e. buy if from somewhere that sell to truck companies not car owners. Its not very pleasant and needs safety precautions and thorough rinsing, especially on metal work.
Beyond that - you are likely into solvents for cleaning. Search the forum for "gunwash" basically a cheap, rather impure, but effective solvent mix used for cleaning spray guns. Both bad for you, and bad for the tubes if not used with care.
You may find more success searching here for "tubes" rather than "pontoons" (which we usually use to mean a floating dock or "sponsons" (which is more common in the US).
