Damage to tank liners by ethanol comes up quite regularly as a question so I'll post my experience from the last couple of days removing an ethanol damaged lining.
The tank had been sitting for a long time with about half a gallon of stale fuel in it and the lining had gone a dirty orange colour and was flaking and lifting.
Firstly I added inserted a 2m length of chain into the tank and agitated the tank at around 15 minute intervals for 3 hours - I then removed the chain and poured out the stale fuel, a fair amount of the liner had been dislodged by the agitation and a lot of it came out with the fuel.
There was still some flaky debris left inside and where the sealer had pooled during application it was still attached to the tank.
I re-inserted the chain and added 2.5l of pure acetone, agitated the tank some more over a couple of hours and then left to soak overnight. The next morning the pooled areas of liner showed some evidence of lifting but would not dislodge by agitation. I made a 'prodger' by joining two old spokes together in a nipple and ground one end to a flat hook profile and the other to a curved scraper shape and using this managed to pick the large lumps of pooled sealer off quite easily, (I assume the acetone had broken the bond). Drained the acetone, removed the chain and more debris.
Next problem was the pooled sealer lumps were too large to come out of the filler orifice so I performed keyhole surgery with a couple of pairs of pliers to break the lumps into pieces that could be removed.
Used an air gun from my compressor to blow out lots more fine debris and to evaporate the remaining acetone then put the chain back in for more agitation, this time dry.
Having satisfied myself that all the liner was removed from the tank walls removed the chain and blew the remaining debris out with the air gun
Here's what came out, don't know what brand of sealer it is:
I've seen references to using a cement mixer to agitate tanks - I wish I had one because my arms are giving me gip today
Regards Mick
