Leakinf petrol tank on lawnmower

[Steve W]

I'm fixing up a 1964 Qualcast Commodore cylinder lawnmower. Great success yesterday, and managed to give my lawn its first decent cut for years!

However, the steel petrol tank is corroded and is leaking at the bottom. I have dried it out, given it a few bashes, and shaken out quite a lot of scale. What should I do next? My thoughts are one of the following:

- Pour in a two part resin mix, enough to cover / coat the bottom of the tank, where the corrosion has been. I suppose I could use either epoxy (expensive) or polyester (cheaper).

- Bare the outside of the tank and coat with one of the above resins (with fibreglass matting?).

- Apply petropatch or similar proprietary patch on outside.

Any advice, please?

Thanks Steve

[Spamlet]

You don't say whether you want to preserve the finish on the tank as a restoration for show, or just to use?

If the finish is not important, or you are able to repaint it yourself, and the metal is not too far gone, you should be able to have it brazed (especially true if it is just the 'usual' cracking around the tap spigot). If it's just the seam that is weeping you might even be able to heat the whole thing up and run some solder down the seam inside. BUT DO make absolutely sure there is no smell of petrol from the tank before you get any source of ignition anywhere near it. An 'empty' tank is essentially an unexploded bomb.

If the metal is too far gone, I would imagine that 'internal solutions' are more likely to keep any holes filled than external. You might even be able to line the tank with some kind of 'bag' if you were just looking to it as a supporting structure. Wonder if one of those shiny wine/cider bags from inside the cartons might be coaxed into service...

Dangerous mucking about with petrol though...

S

[Andy Champ]

Saw the answer to that on Scrapheap Challenge the other day - they were making a diving helmet from an old Calor cylinder, and needed to cut it in half.

So they filled it with water first.

Andy

[Harry Bloomfield]

That would work for cutting it, but the thermal mass when filled with water would make it impossible to braze or solder.

I have heard of exhaust gasses fed into a tank being used to prevent ignition. Perhaps another way might be to leave the cap off, fix the tank down then deliberately ignite the internal gasses from a safe distance?

[The Natural Philosopher]

take the top off and put in on the fire first. That will clear any petrol..

[Dan Smithers]

Steam cleaning it internally is the recommended method - I'm not sure whether a domestic wallpaper steamer is up to the job.

Alternatively there are internal sealers that are used to repair petrol tanks on cars. Try asking on uk.rec.cars.classic.

dan

[cpvh]

This was asked here last season. A couple of points which came up then which haven't come up this time..............

If you use any kind of plastics, they could be affected by the petrol and then block the fuel system in the mover (the poster spoke from bitter experience).

One suggestion was to get some kind of metal drinks bottle such as those used by hikers etc and convert it into a petrol tank.

HTH

[Spamlet]

This was asked here last season. A couple of points which came up then which haven't come up this time..............

If you use any kind of plastics, they could be affected by the petrol and then block the fuel system in the mover (the poster spoke from bitter experience).

One suggestion was to get some kind of metal drinks bottle such as those used by hikers etc and convert it into a petrol tank.

HTH

Yes, jelly in the carb jets is no fun at all!

S

[Andy Champ]

Indeed. I was a little surprised to see them using what seemed to be an electric cutter (thinks - in uk.d-i-y - must have been an angle grinder!) with all that water.

But I bet the water displaces all the petrol vapour!

Like that idea. But be sure you've got enough vapour out.

Even if it works, you might distort the tank.

Andy

[Clint Sharp]

In message , [e-mail] writes

Hmm, seem to remember the camping guys carry their liquid fuel in dinky anodised aluminium bottles as well, trangia, primus and coleman all make them IIRC along with a heap of 'generic' ones from places like Decathlon. Ideal for conversion.