In Progress

Caswell Sealer on tanks with internal structures

After several recommendations from members of a Triumph forum I've just used the large Caswell Tank Sealer kit on my 1997 Thunderbird (tank capacity 15 litres). Firstly it was treated with Rusty Metal, then cleaned and dried. As per instructions I made sure the temperature was within range, the products measured correctly and mixed thoroughly. I rotated the tank slowly in all directions, then excess sealer left to drain. Upon inspection it has left a nice smooth, shiny coating throughout the tank except for the overflow tube which, apart from a few drops, is still bare (this can be seen in pics: running near to the top of the tank, looking down through the petcock hole). Although in reality it could easily be overlooked due to the shape of the tank and it's small openings.
Leaving the tank like this will not fix my current 'rust in the fuel' problem, plus I'm guessing may lead to things far worse (fuel working it's way down in between the sealer and the tank....). Definitely not the desired result after spending a considerable amount of money on this kit. 
Have you heard of similar issues with internal structures not getting covered before?
More importantly, what can now be done to fix this?
Any help would be greatly appreciated. 

2 replies

Thanks for your prompt reply Clare.

Although quite tricky, I guess it could be painted with a brush on a wire. I would like to attempt this but do not have any sealer left, the full amounts were mixed and used in this tank. Even the mini tank sealer is of considerable cost, given that I've just purchased a large tank renovation kit. Would it be at all possible to get a smaller amount of just parts A and B of the sealer?



Dear James,

Sorry to hear you have a problem, I will try my best to help you.

We sell around 3000 tank sealers a year, our average failure rate on 3000 units is 2 per  
year and those can always be linked to exterior damage cause the sealer to crack, or a  
chemical reaction from anything that has been in the tank previously or when installed.

The consistency of the sealer is treacle like as you know and can require a lot of time and patience to coat in a uniform way.  A way to resolve the missed section could be by using a paint brush attached to a wire for example.

You are more than welcome to send the tank to us or alternatively call on 01252 560515, we can give you further guidance.