question Fuel Tank Sealing Compounds

[LarryH57]

Has anyone had a bad experience with using fuel tank sealing compounds such as that offered by Frosts?

 

http://www.frost.co.uk/por15-basic-big-fuel-car-tank-repair-sealer-kit.html

 

I have a replacement tank for my Lwt and although its in good order I thought about using a fuel tank sealer to give it a bit of extra protection. However a friend of mine said don't bother as he knew of another MV restorer who used a sealer on a restored fuel tank but later found that it started to peal away and in turn it clogged up the vehicle's fuel supply.

 

My friend suggested that the sealer used by his friend (not necessarily from Frosts) may not have been able to cope with ethanol in the petrol, so are there things to look out for with such products?

[thedawnpatrol]

Hi Larry

 

i have recently used the Pur 15 from Frosts on my two Morris PU tanks and so far it has been very good, certainly holds fuel ok, its a bit of a long winded process, but needs to be done properly. bought two sets as there are 2x11 gallon tanks and had a fair bit left over, sadly this can not be used as it has a very short shelf life.

 

 

so all good from my view.

 

Jules

[Zuffen]

About 5 years ago I used POR15 on an 80 litre fuel tank in a modified vehicle.

 

The tank only has 98 Octane fuel in it and hasn't given any trouble.

 

You do need to follow the directions to the letter for it to work.

[ArtistsRifles]

One of the tanks on 55 FM 58 leaked like a sieve when half full so when I had to rebuild her 4 or 5 years ago I used one of those frost tank repair kits. Bit of a long job in winter as it has to be washed out with the cleaner then water then allowed to dry thoroughly before the sealant can be added. Certainly worked though - not had a leak since. Runs on base unleaded only.

[matchlesswdg3]

The previous generation sealants broke up when exposed to the new ethanol containing fuels......happened to me, clogging up the fuel system. But I would not use a sealer unless absolutely necessary due to potential for sealant to come adrift, maybe due to lack of adhesion to an oily surface. Its a pain to do properly and not cheap. Why bother on a new tank that should last 20 years?

[LarryH57]

My replacement tank for my Lwt is not new and has had a small hole repaired but it is quite rust free so I may not bother.

 

However the replies suggest that following the instructions and only using new formula sealant is vital.

[TooTallMike]

Hi,

 

I used POR15 about 9 years ago on a MUTT fuel tank. The vehicle was sold on and then was recently bought back by a friend. The tank is as clean now as the day I did the job.

 

You have to thoroughly degrease the inside of the tank so that it can adhere properly. I now use this treatment on all fuel tanks I remove as a matter of course. The inconvenience of having to remove a fuel tank to repair it at a later date makes it a no-brainer for me. I believe any issues with the treatment peeling off are due to poor preparation rather than any issues with the product itself.

 

As already mentioned, you cannot save the left-overs because it cures, so the best thing to do is have a load of degreased Jerry cans and other containers standing by to be treated using the excess.

 

Frosts seems to be the cheapest place to buy POR15. There are other cheaper products on the market but I would spend the extra and get the best.

 

- MG

[LarryH57]

Thanks for all your replies.

 

Out of interest if the Frosts POR15 is poured in to a fuel tank by what method do you block up the holes ASAP while you are turning the tank over and over again to ensure that every surface gets a good coating before it cures. I have been told you can't hang around once the sealant goes in to the tank!

[steph1960]

Thanks for all your replies.

 

Out of interest if the Frosts POR15 is poured in to a fuel tank by what method do you block up the holes ASAP while you are turning the tank over and over again to ensure that every surface gets a good coating before it cures. I have been told you can't hang around once the sealant goes in to the tank!

 

From experiences I have had with the product it stays fluid for ages, I have poured the excess into a can and it has still been fluid weeks later, the can was sealed though. Threaded holes can be blocked off with bolts but the best hole plug for the larger holes is a potato.

[earlymb]

Rust on the inside can usually be removed with electrolysis. It is absolutely vital the inside is completely de-greased before using the sealer, and the same manufacturer usually carries a product for this.

 

I don't know if the current sealers are ethanol-proof; worth to look into. When in doubt use 98, as that doesn't have ethanol mixed in (yet?).

[Davey089]

Ditto , I use the Por15 and I too have poured the excess back into the tin and it stay's fluid . Words Dave Smith, American Car Magazine, April 2016.... There's nothing you can do with the leftovers, you just have to wait for it to set then throw it away, which seems a shame. ? Obviously has money to throw away :-D I have had mine on the shelf for at least 6 months .

also in their FAQ'S Quote :

3. Pour in the entire can of POR15 Fuel Tank Sealer and “roll” the tank around so that the inside of the tank is completely coated. Then drain any excess for at least 30 minutes to ensure that the sealer has not “puddled” in the tank. After you’ve done this, pour the drained sealer back into the can, but Don’t Put The Lid Back On The Can Tightly Or It May Explode! ..really

 

 

 

 

 

From experiences I have had with the product it stays fluid for ages, I have poured the excess into a can and it has still been fluid weeks later, the can was sealed though. Threaded holes can be blocked off with bolts but the best hole plug for the larger holes is a potato.

[TooTallMike]

Thanks for all your replies.

 

Out of interest if the Frosts POR15 is poured in to a fuel tank by what method do you block up the holes ASAP while you are turning the tank over and over again to ensure that every surface gets a good coating before it cures. I have been told you can't hang around once the sealant goes in to the tank!

I use gaffa tape to seal small holes. For bigger ones you can make a hardboard or metal plate and secure it down with either the mounting screws from what ever you removed, or gaffa tape if it's something like a filler neck.

 

Chase out any threaded holes afterwards with a tap.

 

- MG