Fuel tank

You do not present the entire scenario but just some things to think about. If your tank is not leaking gas out of it, then water is probably not leaking in. This leaves usually one place for the water to come from, condensation. There are many opinions on this topic on this site. I will tell you what has always worked for me and it makes sense. Always leave your tank full, a full tank does not have room for condensation. Always add STA-BIL fuel stabilizer in the off season with a full tank and anytime the boat will be sitting. Occasionally add a specific water separator to the fuel.

As for the silica appearing material, I would look right back at the condensation issue. Water residue (calcium) leaves a white powdery substance as it dries. This can only happen if the tank is left less than full allowing room for condensation. If you are not someone who does ongoing maintenance on your fuel tank with every fill up, you might consider becoming one. The environment plays a factor in condensation and most people do not think about it. Big temperature changes is more cause for condensation. Tank maintenance may be your answer. If lack of maintenance is the issue a poly tank will not solve your problem.

Hello correctcraft friends.    I have a 76 mustang. Want to feplace the aluminum gas tank with a polymer one, can anyone reccomend a place to buy one.   Old aluminum one has always had a water problem and last year found alot of silica in it. Any info would be greatly appreciated