Hi Dicky
I’ve used the older type of tank liner and they were quite good until the introduction of ethanol in petrol, at which point the lining either dissolved or softened and detached itself from the tank. Ethanol content in petrol is going to be increased from 5% to 10% in the near future which will make matters worse.
All is not lost though, as tank liners are available which are ethanol resistant – I can’t recall the names of these products offhand but they are advertised in magazines such as Old Bike Mart. Just make sure when you buy or order, that you ask if they are resistant to ethanol.

In the meantime, use only TOTAL petrol, because at the moment it is the only one that has no ethanol in any of its grades of petrol, and it won’t harm existing tank lining materials or glass fibre tanks. Due to pressure from the Government this situation will change in a couple of months time, but TOTAL say that their premium petrol called TOTAL SUPER will remain ethanol free, and to me that looks like a great decision, and I will buy from them even if it means driving several miles and filling up a jerrycan just for use in my bikes, and if the car needs a fill-up too then it will get TOTAL as well. I just hope that it isn’t too expensive. If you go on their website and enter your postcode you can download a list of the nearest filling stations.
I had truly horrendous experience with the Frosts tank lining products in my 1989 MZ ETZ, and will write an article on the subject for Yowl., so that all members get to see it.
Brian

It wasn’t so much the sealant as the useless cleaning solution “Marine Clean” and the equally useless derusting chemical, compounded by the offhand unhelpful attitude of the guy at Frosts that I tried to discuss it with. (It was a three element pack of chemicals that I bought from them)

Hi.
It is remarkably easy to remove old Petseal, and it is sensible to do that rather than trying to apply something over the top of it as you don’t know just how well it is bonded to the metal of the tank. If you Google “Petseal Remover”, you will find the website of Potter’s Tankcare Products in Norfolk. He does a very effective Petseal remover that is very easy to use. It comes in a small plastic bottle that you just pour into the tank, make all the fillers and tap holes, etc., airtight, rotate the tank over and over a couple of times, and leave it overnight. The vapours are VERY poisonous, so do all this in a well ventilated place, outside if possible. In the morning you should find that the petseal has turned into loose flakes about the size of Cornflakes, which can be shaken and hosed out. You MUST wear rubber gloves and eye protection whilst doing this as the flakes will burn on skin or eye contact. It is also damaging to paintwork so you must protect the outside of the tank with some thick polythene, carefully sealed with duct-tape around the filler neck. Potters also do rust remover and ethanol-proof sealer, so you can order the lot in one deal. One word of warning….Make absolutely certain sure that your tank is free from any oil or grease contamination before using any of these products or they won’t work properly. Careful preparation is vital. Also, when ordering, don’t underestimate the size of your tank.
Brian

Further to my previous posting about Petseal removal, I think that it is probably Methylene Chloride, which anyone with industrial chemical contacts may be able to scrounge, thus saving a few more quid. Do however be very careful with it, and if in doubt download some “Elfansafti” info from the internet. If that frightens you off Potters can do the whole job for you!
Brian