Tank liner?

I've just acquired a '71 Commando Roadster Mk.II. The fuel around here contains 10% ethanol in the warm months, and I'm concerned about it attacking the fiberglass tank on this bike. I've read about Caswell's and other products for coating the tank. However, when I look into the tank, I see a smooth bright blue surface. Is this the appearance of a tank that has already been lined with one of these products?

Good question. Here is a pic of an unmodified fg tank (except for the black paint) that was originally fireflake blue.



Most of it inside is pretty shiny except the bottom part which seems to have some residual brown crud in the bottom.

Personally, I have heard of disasters with the coatings and good results too. I am not sure what I am going to do with my 69 fg tank. I may try to buy fuel at the local airport that does not have ethanol, but that is not a solution for long trips. I still wonder what boat people do that have the fg tanks.

Dave
69 'S' project

From experience, DON'T use POR15 in fibreglass tanks.

It comes away after a couple of days, this was in a new fibreglass tank that was prep'd as recomended.

After i cut the bottom of the tank to get the bits of POR15 out, I relined it with Hirsch tank liner.
2 years ago and still good.

Now that is a very interesting picture there, DogT. That is what mine looks like - including brown crud in the bottom. It's black on the outside too. Maybe this bike has a tank that started life on a fireflake blue bike?

A friend tells me that BP gas with "Invigorate" (whatever that is) doesn't contain ethanol, and Marathon has Marina 90 and Marina 91 that doesn't have ethanol. Still investigating....

+1 on Hirsh (so far) see this post on sealer gas-tank-sealer-t4653.html

Jean