Mission impossible – accomplished
With the help of my very good friend Nick Cleak, the replacement fuel tank has finally been fitted to the Davrian. This job proved to be every bit as tricky as I was told it would be, yet it also turned out to be hugely satisfying.
Using a disc cutter, Nick very carefully cut around the perimeter of the tank, which I'd marked out, keeping as near to the door jamb, wheelarch, and inner bodywork join as possible. Once cut, this complete section of fibreglass was peeled off and safely stored in order that it could be reused. Next (and the first of the 'messy' elements of this job) was the foam removal. When both tanks (there's one either side) were originally installed, fire-retardant foam was poured into the cavities. As the foam expanded and hardened, it encased the fuel tanks, a great safety measure.
Of course, to remove a fuel tank, all of the old foam has to be removed first. This is a most unpleasant task that took hours and hours, the most difficult part being the extraction of the foam from beneath the tank, simply due to the lack of access. I used a Dremel with an extended flex shaft and grinding attachment, wood chisels and a number of suitably bent scrapers I'd fashioned. Once the majority of the foam had been removed, I was able to wiggle the tank and lower it into the lower part of the sill. Doing this allowed the filler neck (which extends above the inner bodywork by a few inches) and hence the tank to be freed from its resting place of 40 years.
The reason for the tank's removal was found to be a small rust hole near its base. However, comparing tanks, it quickly became apparent that the new one I'd bought was a tad larger than its predecessor, meaning that fitment would require more of the inner wing to be cut. Undaunted, Nick set to and deftly removed a 3in wide strip. With access gained in this way, the new tank was teased into place and the filler neck poked through its locating hole. Then the base of the tank was supported with chunks of the old foam. These held it in the correct position until the time came to pour in the new mix, the liquid then flowing beneath the tank and completely fillimg the cavity.
However, before this could occur, we had to reinstate the sections of inner wing we'd removed. They were then left to cure overnight, and the following day Nick and I got stuck into the foam refill. We reckoned this had the potential to be the trickiest part of the job, and we weren't wrong! Despite mixing the advised amounts of resin and activator and stirring for the requisite time, the foam did its thing rather more quickly than anticipated and started expanding as soon as I tried to pour it in. In brief, there was an eruption that almost rivalled Vesuvius and the resulting 'lava flow' took quite a time to clear. Fortunately, I'd ordered plenty of resin and activator, sufficient for us to have a second go.
Understandably, this was a case of once bitten, twice shy and we stirred for a shorter time so as not to get the materials prematurely 'excited!' Even so, I was only just able to complete the pour (we'd left a small opening in the inner wing to aid this) before the
foam started hardening and expanding. This happens very quickly, and as the chemical reaction takes place, a lot of heat is given off. Every inch of the inner wing was warm to the touch for quite some time.
Returning the next day we were delighted to discover that the foam had hardened perfectly and that there had been no foam ingress into other parts of the car. Not that the install was quite finished, as it was necessary to reinforce the whole area with two layers of fibreglass sheet. Thanks to Nick's expertise, this went well and the inner wing ended up looking even better (and was stronger to boot) than it did when the car left the factory. Pleased with progress, and needing the fibreglass to cure, we downed tools for the day and I vowed to return the next day to connect the fuel pipe and breather.
On the old tank these were welded to the tank body, but on the new tank threaded bosses had been fitted. To utilise these, suitable unions were required. Following a lot of help from Torques in Abergavenny, I'd obtained unions that were low profile (necessary to clear the bodywork) and able to pivot (so that I could angle them correctly). These were then attached, via adaptors, to the fuel line and breather pipe using SAE J30 R9 petrol pipe. This is Viton-lined to resist the effects of modern fuels, including those that contain ethanol. The pipework marked the end of the install and, with fingers crossed, I poured in a gallon of super unleaded and checked for any leaks. Thankfully, there were none. I treated the inner wings to coats of satin black, and that was that – the job I'd been putting off for aeons was completed. Not that the Davrian is quite ready for the road yet, as I need to turn my attention to the brakes, which are still not quite right.