flarityj - 12-5-2006 at 09:28
This is my second post. I have a new Clarke aftermarket gas tank for my bike. This made from Cross Linx PE EXX.
The bike community would love to seal these tanks on the inside. Although I see postings on the safety of this material with various chemicals that
go into gas, believe me that it works its way around and degrades the tank. They usually do not last 10 years and you can't paint or use decals
because of the constant venting (the polar bears don't like it either).
Since your other threads have convinced me to give up elemental F as a sealer (it works), I am looking for something else.
Putting a paint coating on the inside is an excellent way to clog your filter (we have done that with lots of different "plastic" compatible paints).
I can't find any bike guys who have a solution.
Joe
Buckley, WA
12AX7 - 12-5-2006 at 11:48
Weld it *properly*? 
(Hmm, if you're talking about plastic, well you can weld
plastic too.)
Where's it leaking, anyway?
Tim
bereal511 - 12-5-2006 at 15:24
I think what he means is how can he prevent gasoline from leeching and damaging the HDPE plastic of his tank.
Do you have a diagram of what the tank looks like? I'd like to know where the filter is located.
[Edited on 12-5-2006 by bereal511]
flarityj - 15-5-2006 at 04:45
Off road tanks generally don't have a gas filter. You can put one inside at the petcock, but the serious guys put a clear one externally so they can
monitor the debris that collects. The cap is vented with a straight piece of 4 mm tubing.
If you seal the tank vent and leave the bike out in the summer sun for a week, your bike won't start very good because the voltile component of the
gas will have leached right through the plastic. I imagine the government will get around to banning it after a while. It has a greasy, wet feel
to it and reminds me of ABS.
I have found out a bit more on Cross Linx PE EXX. It is unlike injection molded HDPE. It is used mainly in Roto-mold fabrication and crumbles when
the traditional Fluorine treatment is used.
I suppose that professionals have been paid plenty to fix this issue and came up short so far. But it is worth a shot.
Joe
bio2 - 15-5-2006 at 16:24
The HDPE jerry cans that are "fluorocarbon" coated, how are those made?
Elemental F? Maybe HF could be made to work to flourinate the surface molecules.
The flourinated HDPE has much less "porosity" to gases.
flarityj - 22-5-2006 at 05:41
From Reading their website:
http://www.fluoroseal.com/
It appears to be elemental F with a mix of hydrocarbons that are integrated into the plastic. It makes Cross Linx PE EXX too brittle to be useful
though.
Joe