Petrol Tank leak blues!

A leaking tank can result in a fire , makes the cost of a proper repair or getting a new one (even if you get an Indian made one and then have it fettled and painted) seem a bargain.

I would take it to someone who is recomended and not try putting a liner in it, cracks tend to get bigger and rust does not stop unless treated.

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When I thought I had completed a Manx restauration and filled petrol to start it, I found the tank leaking. Didn't like the idea of a potential fire. It is not uncommon with fuel tanks cracking due to vibrations. To find the crack I used compressed air at just slight pressure. Using leak finder (soap water works too) the crack was easy to locate. Opened the cap and continued a small flow of compressed air for two days to let remaining petrol evaporate. Meticulous cleaning of the surroundings of the crack to minimize risk for pores. Then had a good welder fixing it.

Hello Nick,

Have you a radiator repair specialist somewhere local to you ? If so go and see them. They are usually experts at soldering/welding and already have the leak detection equipment required.

Patrick

On leak finding, a VERY small amount of overpressure is needed as air leaks much better than a fluid. If the crack is close to a bracket, welding is needed. On less stressed parts of the tank, tin soldering might suffice. A tinsolder on my Venom has not failed for more than a decade. I've also seen a tank where a blob of polyester or maybe epoxi on the outside kept the tank leakfree for more than twenty years. Don't recommend that.

Mike

Nick,

If you have the correct rubber washers, cupped washer, and bolt for securing the tank then the tank is rubber mounted at the rear.The special tank securing screw and washers are also used on Featherbed frame, I believe. I've seen them on the NOC spares site.

If the rear tab on the tank is bolted directly to the metal tank mount of the frame, your tank will be subjected to more strain and more vibration. Commonly seen on lightweights. Make sure you have rubbers on the top frame rails too.

I'm sure the best solution for you will be to get the tank welded and restore the rubber mounting if necessary.

Peter

If you get stuck tanks come up fairly often and arenât very expensive.

dan

Those figures sound grossly inflated; obviously the person concerned didn't want the job and deliberately quoted you a figure which he knew was ridiculous. Most people are very cautious about welding a fuel tank because of the risk of an explosion from petrol fumes so the tank needs to be well purged first. The actual job itself shouldn't take more than 15/20 minutes.

I have only ever welded one petrol tank; on a Honda VFR400 and that worked perfectly but I do admit that I wasn't too keen on doing it. I think I filled the tank with water before welding on the advice of an expert welder.

I will post the company tomorrow, I got a Triumph tank undented, pressure tested, leaks welded, badge holes relocated and tank top rack inserts added for £110 a few years ago. Very pleased with the result.

If you use water to get rid of remaining petrol, it is extremely important that the tank is completely dry before welding.

run exhaust gases through the tank for 10 minutes, the heat and the fumes purge any petrol fumes

They come up on eBay fairly regularly, for about 40-60 quid, and the club has a couple for half that. There has been a painted one on eBay for silly money but that seems to gone for the moment.

Dan

Hello Nick,

Tanks also turn up at auto jumbles and don't normally fetch very much money but it is a bit pot luck how good they are. I got one at Stafford a couple of years ago for £10 and it turned out to be much better than it first looked; no dents and no leaks but the most horrid paint you have ever seen.

Your original paint from the sixties was cellulose based so really if you intend to use the bike (other than just to the occasional show) then a respray in 2K would be a better option. Matching the colour shouldn't be a problem - just take a sample item such as the tool box lid to the paintman" at your local motor factors. The painting itself is a bit of a pfaff as you have to do a first base coat in silver before actually spraying on the blue colour base coat, then finish off with 2K lacquer which is petrol resistant .

If you live near a country area you could call with the local agricultural workshop and ask them about repairing the tank. These people are usually the old fashioned mechanic/engineers who can do anything- fix tractors/weld gates/make trailers; they normally also have very good up to date equipment such as tig welders/lathes etc. and are used to fixing all sorts of odd things for the farmers.

Patrick

Thereâs a tank on eBay at the moment, not that it looks very good though! Also some styling panels and delux panels and a nice looking Nav in red.

This is the tank repair company I used.

Www.cwclassic.co.uk

I sent them lots of pics and then they sent me an estimated price, this was the price they charged after the work was completed.

Nick, I may have missed something but the NOC shops shows at least three petrol tanks for sale for 'Lightweights' all around the £25 mark. I paid £65 for mine off eBay plus £15 postage so the ones in the NOC shop sound like a bargain. They are showing as 'in-stock'.

Dennis

Previously Nick Clarke wrote:

Thanks chaps, all wise words - its a real shame because the bike has never been restored and has a lovely patina which is going to be spoilt once I have repaired the tank because it will have to be resprayed. Tracking down a good welder willing to take the job on will be a challenge I suspect and you never know what horrors you will find when you start welding a 54 year old petrol tank! I had a look on ebay and see new Indian made Lightweight tanks are available from a vendor called Shopperstop-25 for £225 - does anyone have experience of their quality and accuracy of fit of the badges and on the bike?

Nick

If I had a tank and side panels with original paint and patina , I would take them off the bike and put them in cotton wool because they would be irreplacable and could always be put back. I would then source spares to replace, and paint however looked good to my taste and not worry too much about originality as the originals are in cotton wool. A simple solution to a leaking tank is there , it just needs careful thought.

GRAHAM

No bids up to now on the Ebay tank - it does say £10 or best offer - and it appears to have both cap and badges. The badges should be worth that, so it should be worth an enquiry at least if anyone is near Ipswich who could collect and save the £20 pound odd postage cost.

The same advertiser also has other Jubilee stuff but a lot of it appears to be totally incorrect and effectively just junk. He also has a pretty poor rating.

I sent him an email about the battery and tool box, politely suggesting it wasnât from a jubilee, he replied saying âthatâs what they came offâ so he obviously knows best!

Yes I have to agree with that. He had a "Jubilee" headlight a few weeks ago - I think for £10-which was obviously not from a Jubilee but someone probably got a bargain as the speedo was a Smiths 120mph chronometric which looked all there.

Thatâs a shame, I was hoping he had a headlight shell, i have an early one but need a 6 1/2 inch one!