plastic fuel tank

[scottgrissom]

Hey guys,<br />Does anyone know if a heavy duty plastic gas tank will expand over time. I'm considering buying this tank but it is a very tight fit between the stringers.<br />Scott

 

[Mark42]

Re: plastic fuel tank

The issue is not expanding over time, its expanding as soon as you fill it. The Moeller plastic tank I bought said to leave at least 1/2" on all sides for expansion. The tanks "breathe" as they fill and empty, with temp changes, etc. Tank manufacturers generally suggest against foaming in the plastic tanks for that same reason.<br /><br />What tank are you looking at? How tight is your "tight fit"?

 

[epresutti]

Re: plastic fuel tank

RSDG,<br /><br />I am with Mark42, the instructions for my plastic said it can expand from 3% to 5% in all directions. They have an installation procedures that basically has four "clamps" that hold the tank down, that are spring steel, given some notches in the top of the tank, and then two "bulkheads" that keeps if from sliding, front to back and side to side.<br /><br />Definately don't foam it in. And if it fits real tight, when it expands it could deform the stringers.<br /><br />Peace.<br /><br />Ed.