Recently I've noticed along the filler hole the oil has taken on a sappy consistency. I'm concerned about what could be going on inside the tank. Have others experienced this. I've thought of adding B99 to the veggie tank to see if this can dissolve some of this stuff.

Rich

This is polymerization.
It tends to ocurr in places that VO is spilled or forms a thin layer since it is an oxidation of the VO and requires good exposure ot oxygen as part of the reaction. It can also occurr in tanks if ther is a lot of sloshing(air mixing) or if the tank is run very hot.

Heat also speeds polymerization.

I also believe that moisture (ater) speeds polymerization...but this is currently under some debate.
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If your VO tends to be over 100°F in your tank and has few baffles this may occurr in your tank as well forming a layer that has been referred to as resembling "chicken skin" or "fruit roll up". The only real problem I have seen with polymreization in a tank is if large chunks of it begin to slough off and clogg lines or filters.

I remember reading the chicken skin/polymerization thread a month or so ago. I am not using an in tank heater and this is the stock fuel tank. Has anyone attempted or tested adding b99 to see if its solvent properties can dissolve this?
Rich

quote:

I remember reading the chicken skin/polymerization thread a month or so ago. I am not using an in tank heater and this is the stock fuel tank.

Trying to not be paternalistic here...
This is polymerization.
It tends to ocurr in places that VO is spilled or forms a thin layer since it is an oxidation of the VO and requires good exposure ot oxygen as part of the reaction.

VO will form this wherever you leave a film on a surface exposed to the atmosphere.

Why do you want to dissolve it?
It only causes problems when it loosens and clogs filters or lines.

quote:

Originally posted by SLO_TAO:
I remember reading the chicken skin/polymerization thread a month or so ago. I am not using an in tank heater and this is the stock fuel tank. Has anyone attempted or tested adding b99 to see if its solvent properties can dissolve this?
Rich

Rich,
I have a similar 'skin' forming in the filler neck of the stock tank. I feel that it is not a problem at this time and I will deal with it when it does become a problem.
I use a blend of biodiesel and veggie as my start fuel, in the stock tank.
So the Biodiesel in the blend has not prevented or removed the 'skin'

If yours is not causing problems, leave it alone.
Like Dana has posted, dislodging it could cause more serious problems.