Fuel Tank Pick Up Alloy

[bever]

The pick up tube on my 175 gallon aluminum tank is an aluminum fitting with a plastic tube going 17" into the tank. I'm concerned that the ETHANOL will degrade the plastic and decided to replace the assembly. After reading suggestions on this site, I decided to use a brass fitting with a sweated copper tube as the dip tube. Easy enough. Then, I had the pleasure of discussing this action with a rep from the tank manufacture and he advised against the copper tube in the aluminum tank. His reasoning was that the dissimilar metals would create a DC galvanic reaction at the end of the tube and cause corrosion at the bottom of the (aluminum) tank near the end of the copper pick up tube. I think I understand his point but would welcome any input from Saltier dogs than I. If not copper than what material? I could use aluminum fitting with an aluminum tube? Weld, glue, solder??
This vessel is a '95 251 Proline used exclusively in salt water.
Input?

[knotreel]

I would NOT replace the plastic tube. The plastic tube does not have a tendency to fatigue and break off like a metal one has. Your 17" tube if it were metal would have a good chance of breaking off as it's length will amplify the jarring and vibrations that could in a surprisingly short time cause it's failure. I would venture to say that a great number or perhaps nearly all professionally built metal in hull outboard gasoline tanks have the "plastic" pickup tubes. When you hear of them melting off then I would worry, otherwise you are going to create the very problem you fear with a broken tube.

[bever]

Roger that. Fatigue resistance is for sure a plus. The Ethanol issue is prompting extra P.M. thoughts. The plastic pick up material is a nylon and is very resistant to the alcohol I'm now finding out. The tank has two pick up points. One for sure will be a spare and or water drain sump.
Thanks for the input.