STEP ONE: PREPARING THE TANK WHAT WILL YOU NEED?
Irrespective of the sealer, you need to make sure the tank is cleaned and prepared inside or nothing will stick to it. If it has an old sealer in, that needs to be dissolved, rust needs to be converted and removed and old, stale fuel also needs to go. It goes without saying that most of the chemicals and acids used here are not nice to say the least, so gloves, protecting paintwork and ventilation need to be seriously tackled. Tanks have one or two holes in for fuel taps, pumps or even fuel level gauges. These need to be bunged up with stout dowels, as they will also need to be removed several times and then re-instated. Larger holes may need gaffer tape to fill. Lastly, you need to consider temperature, depending on what the sealer manufacturer recommends. Ian has found his epoxy sealer works around 22°C or above for the sealer to flow well. Too cold and you will risk not getting full coverage, so Ian also has an insulated area with heat lamps to help.
Our tank hadn't been sealed before, but it was rusty and it had suffered from pinholes, which Nev had filled, but we wanted to make sure. Some rust removers claim to make the rust back into steel, but I cannot see how that works, so prefer the ones that remove the rust using acid. This was what Ian provided and included a rust remover which you keep in for several hours, regularly shaking the tank. Ironically it's mixed with hot water, but does do a good job of clearing the rust, just like the rust killer you would use on bodywork. •
To remove an old sealer you'll need to soak the tank for several days with a 'petseal remover', that soaks into the old sealer and either dissolves it, dries it out or otherwise attacks it so you can get it out. Some bungs will have to be made for any tap outlets, from wood, cork or dowel. Messy and time consuming, how long it takes depends on the old sealer. "It's not uncommon for me to have to cut holes underneath a tank to get areas you can't reach from the filler, or even to remove large lumps of old sealer," explains Ian. Once you're happy all the sealer has gone, it's time to tackle any rust or corrosion.
The two-pack sealer comes premeasured, so you just need to find something to pour it all into and stir it up. As the BMWtank is so large, I needed to cut up a milk bottle, but it worked fine. As you stir it the grey hardener lets you see if any part hasn't mixed thoroughly, then pour it in, making a note of how quickly it is moving.
This is where I found it tricky. With tape firmly over the filler hole, I'd been used to shaking the previous concoctions, but the sealer is much slower to move around inside. And it is going off all the time, so you have to plan where it's been and where it needs to go. With 750ml in the BMW tank there was plenty, but because you cannot hear it splashing around, I found it tricky to keep a track of where I'd covered. So I had to keep removing the tape on the filler and peering in with a torch to see!
Ian's tips were essential. Make sure the top of the bridge and the front and back are covered - areas he often sees have not been covered well enough. Don't be afraid to use a fine art brush attached to a stout piece of wire if you need to touch up the breather tube, or any other parts not covering. And as said, make sure the temperature is warm enough to keep the sealer moving inside.
Once you're happy it is all covered inside, including the filler, drain the remaining sealer into the bin through the fuel tap holes. The tank will now need around 6-7 days to cure, with the more air flowing through to remove vapours, the better. Ian uses (and sells) mini USS-powered fans to help.•
HOW DO I KNOW IF IT'S WORKED?
Some tanks should be easy to see inside, while others, like the BMWone, are very tricky, thanks to the large bridge in the middle. I used a powerful shooting torch through the tap hole and a dentist's mirror to check around, with the only part needing a little more being the breather tube. Luckily there was enough left in the milk bottle and I could reach with an artist's brush. If there are larger areas you've missed, you can add more sealer as long as you do it before the sealer has cured.
WOULD I DO IT AGAIN?
No, to be honest. I would pay someone like Ian to do it. Mainly because they have all the extra tools that make the job easier like sand blasting and welding, they know what to do and there is so much to go wrong if you don't get it right. I'm glad I've tried it, the tank seems to be alright, but next time I'll happily pass the job on!