The new generation of liners is advertised as ethanol proof. I used "Slosh" on recommendation and it worked well on a tank that I needed to protect from futher corrosion after a proper repair with new metal. Its probably best to ensure you have a fuel filter of some kind in the fuel line.
thanks ferg, ive allways had fuel filters on my bikes including my everyday ride a 20 year old harley fatboy, it allways makes the ride more reliable, i will have to find a way to put on the m20? if anyones done this would like to hear how, thanks, tony.
Caswell liner is a 2 part epoxy type liner. I've never had it break up but imagine if it did, the bits would be quite large. The stuff sets like a rock and does not "puddle" which is a problem with brands like Kreem. When liners "puddle" it can set like a blister and remain liquid inside. if the surface is then punctured, the liquid component can run into the carbs and foul everything completely.
I've actually left some surplus Caswell mix in a jar to see what happens. The jar was about 1/4 full and the entire contents set hard. Its important to follow instructions to the letter, but from memory, Caswell is fairly unfussy about the condition of the tank surface. You might need to temporarily plug the holes in the tank with JB weld or similar. "Seal all" works very well for pin holes too.
Its also the ONLY liner to use on fiberglass tanks.
The only thing I would consider putting inside the tank is POR 15.
It is a furane resin that sets by undergoing a chemical phase change which does not release any gas so there are no gas escape pinholes in the linning.
It is acid, alkali pertol ,benzene, tolluene, acetone,ethanol and oil proof.
The only thing that affects it is UV and I would hope there was none of that inside your tank.
POR 15 will also set through no matter how thick it goes on so if it runs into seams , it will set hard there and is thin enough to allow to continue down into the tap holes without blocking up the threads which is where most tank linners start to fail.
As for the pinholes, if they are really small tin the bottom of the tank then build it up with lead wiping metal ( now tin , antimony cause lead is the devils metal )
If you use something like tinning butter and you have cleaned the tank properly it will run inside the tank and tin a lot of the inside of the tank floor thus making lining unnecessary.
For filters you can now get metal canister filters for lawn mowers.
Thus they can be painted green and look correct on a military motorcycle or black for a civilian bike.
The M2O originally had the petrol filters inside the tank,these are off my tank I took them out when I had some dents removed,the tank was blasted and is solid,but they should be ok with a tank sealant.