GPP mower fuel tank leaking

[A.Clews]

I have a GPP LawnPro rotary petrol lawnmower that I bought at Focus DIY three years ago for only 89 quid. I thought at that price it would probably break after a year but to my pleasant surprise it still works just fine... except that it has developed a leak from the fuel tank, and it's a bit dangerous to store it (and probably use it) as such. The leak is from the tank body itself, close to the fuel outlet, not from the pipe joint, and the assembly being plastic doesn't look like it can be repaired easily.

Does anyone know where I might get a replacement tank (it's an integral moulding with the top cover and cooling fan housing) for this brand? Focus no longer sell them as such, but do sell very similar mowers under the Champion brand name for 99 quid.

I guess for a petrol mower as cheap as this, I'm probably on to a loser, but it seems a shame considering that the rest of the mower is working fine.

[Dave Liquorice]

The question you should be asking is who made the engine, which you can probably answer yourself by looking under the covers. There are very few small engine makers out there and these cheap branded mowers nearly always use Briggs & Stratton or Teuchemsh (or how ever they spell it...).

Once you have the engine maker, model, type and serial number wander off to the makers site and see what spares are available. The engines come as complete units that the mower maker just bolts onto the frame.

[Stephen Howard]

It's Tecumseh.....'Teuchemsh' is what you say when you've bought one and found out it's a pile of poo.

As regards the leaky tank...you could try slapping a dollop of JB Weld on the crack ( remember to degrease the crack first with lighter fluid ). Might work, JB Weld is pretty tough stuff....and if it doesn't you'll only have blown a fiver or so.

Regards,

[A.Clews]

Thus spake Stephen Howard ( [e-mail]) unto the assembled multitudes:

Thanks, I'll have a look out for that. I did think of using Plastic Padding or Isopon but I doubt that it would provide a good seal. I can't see exactly where the leak is and it's obviously just a hairline crack, but a leak is a leak is a leak...

[spamlet]

Not easy to judge the likelihood of success without seeing it, but, if you can dry the tank sufficiently (and if you use two-stroke, degrease it as well) - then you can possibly rig up a vacuum in the tank by turning off the output tap and putting the vacuum cleaner over the fill hole; whilst liberally applying 'araldite' or similar to the area of the crack. This could ensure penetration...

...On second thoughts, if the material is quite flexible then vacuum would tend to close the crack, so a better approach would be to use a long spatula or similar (carved bit of stick) to coat the crack area from the inside and then blow into the filler hole. Don't use the rapid araldite as you probably would not have time to do this before it began to set.

I mended a car radiator this way, when I was surprised to discover the output 'spouts' were made of plastic and came off more easily than the rubber hoses! Sounds like your tank might be a similar thing, where the base of the 'spout' is starting to part company with the tank body.

...And a third suggestion - if you get all the flammable stuff out of the way first - would be one of those hot glue/plastic 'guns' to weld the crack.

and, if all else fails, you could drill out the offending spigot, and glue in a new one of your own design (one of those flare ended pipe inserts used in speedfit plumbing might do the job); you could even tap the hole...

Should be plenty of clever bods around the uni to help (certainly used to be...). And if the 'denture' in your address is significant, there should be some PDG adhesives and tools to hand!

S

[A.Clews]

Thus spake spamlet ( [e-mail]) unto the assembled multitudes:

The tank was already dry, having (a) leaked most of its contents into my shed over the last week or two, and (b) been drained of remaining fuel and left open to dry out. I ended up buying some Unibond epoxy-based plastic repair goo, and after cleaning and drying the affected area, liberally spread the mixed goo around the join. It became hard in about 20 minutes, so had plenty of time to spread it around. Will leave it for a few days to cure.

Repairing it from the inside as per your second idea was a physical impossibility.

If it still leaks I might have a go at your vacuum cleaner idea - thanks.

[mround]

I have a smilar problem and was considering using a soldering iron to melt the plastic and 'weld' over the crack. Obviously will remove and wash out the tank first.

[The Natural Philosopher]

I have never found that very satisfactory.

One approach that may work is a hot glue gun.

spent a lot of time this weekend watching someone repair foam plastic aeroplanes with that...

[spamlet]

I'll second that: plastic usually shrinks away (assuming it is not a thermosetting kind) from the hot metal and needs a filling plastic of similar nature to the bulk to achieve a satisfactory weld or bond. (eg: its no good trying to stick flexy with rigid; thermosoft with thermoset; solvent with polar etc.)

S

[spamlet]

Liquid fuel is a complex mixture and often leaves an oily trace after evaporation. This would be particularly true of a two stroke fuel or if you were using an engine without a built in lubricating circuit (if there is such a thing). The upshot being that a 'dry' tank is seldom a good surface for adhesives without further cleaning effort (for example, I once stove enamelled my Ducatti crank cases, but, the metal being rather porous, I had the devil of a job degreasing it before it was clean enough to take the coating. On the other hand, I have built up teeth of plastic gears, with araldite, with some success on occasion!)

Good luck.

S

[A.Clews]

Latest news:

Today I half-refilled the repaired tank, and used the mower for about half an hour. No sign of leakage! I'm touching as much wood as I can lay my hands on, but I'm feeling reasonably confident that it's sorted and my mower has another lease of life.

[A.Clews]

Thus spake spamlet ( [e-mail]) unto the assembled multitudes:

I certainly take your point, but as the leak was a very slight one (all you saw after drying the area was a film of fuel spreading from the area of the leak, and it took quite a while for a droplet to form. I'm hoping therefore that my fairly generously-applied epoxy repair will provide a sufficient seal and that there won't be sufficient pressure from above for the fuel to get past the repair, especially as I'm only half-filling the already pretty tiny tank. The next few days or weeks will tell (see my other posting from a few minutes ago).