Petrol leak

[caretaker]

It's my lawnmower tank that leaks, it is a plastic one and it is the bottom were the pipe comes out.
I have got it on the bench and put a little petrol in the tank to see the place it is coming from.
It is like a seam on the bottom and the petrol pipe attaches to this.
I am thinking of Aroldite or car body filler, any suggestions?
I can get the tank off easy and the part that leaks is a square bit with the pipe molded in the center, all plastic.
It is the outside square edge seam.

 

[Anonymous]

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[SketchUp Guru]

Hom much for a new tank?

Replacing the tank will probably be easier and result in less time spent than trying to seal the leak. I don't know what you have available for sealants that would resist petrol but many of the petrol resistant ones don't stick to plastic well either.

 

[Anonymous]

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[ike]

Weld it with a a soldering iron or even quicker with blowlamp. Make a plastic 'filler rod' from a piece of scrap plastic like an icecream container. Must fill tank with water before inverting to make safe. :wink:

 

[caretaker]

How about fiber glass from Halfords, would that work?
It is an idea to buy a new tank but also would like to repair it my self if it can be done.
This is its second tank the first was changed under the warranty a year ago.
Not sure about a soldering iron but if all else fails what can I loose.

 

[Tusses]

another vote for welding.

 

[SketchUp Guru]

Epoxy is the common bonding agent for fiberglass but epoxy doesn't stick to most plastiscs well. Welding might work if you're careful but the water thing would be important. No petrol around when you are doing it.

Sounds like this is a common problem. I'd buy a couple of spare tanks to have on hand even if you try welding it. That ought to cover you for awhile. Or do you know a tinsmith who might make you a proper tank of metal?

 

[Tusses]

welding is not a problem unless you use a flame !

a soldering iron is quite safe

 

[Jenx]

If you are going to go with a filler rod, may be an idea to ensure you match it to the kind of plastic that the tank is made of...

"Plastic" as you know, is a generic term for many different products, eg :
ABS , uPVC, PVDF, cPVC etc, and to ensure a 'weld', you'd probably be best to keep it as "homogenous" ... if you mix 'em, it would effectively become like brazing or silver / utectic soldering, in 'metal' terms.

think of it like 'solvent welding' if you like ... you cant solvent weld ABS to uPVC, it doesnt 'take'... and i'm pretty sure you'd encounter similar problems trying to achieve the same result with heat, if you don't maintain the parent material / filler uniformity.

Just a thought :wink:


Bear in mind too... a 'near empty' fuel tank is usually more hazardous than a full one... you start applying heat to it, and whether thats by 'flame' or just the application of heat.... overcome the flashpoint of the combustible material / mix within the tank, and she'll catch fire allright... Proceed with caution !

 

[PowerTool]

Bear in mind too... a 'near empty' fuel tank is usually more hazardous than a full one... you start applying heat to it, and whether thats by 'flame' or just the application of heat.... overcome the flashpoint of the combustible material / mix within the tank, and she'll catch fire allright... Proceed with caution !

Quite correct - as liquids don't burn,it's the vapour;also,as said,the mixture needs to be correct - i.e.between the Upper and Lower Explosive Limits (UEL and LEL) which is the same principle as the carburettor or fuel injection on a car - too weak won't burn,too rich smothers itself.

And assuming you fill the tank with water to remove the petrol,when you have finished,remember to clean/dry the tank and possibly rinse with petrol to make sure you've got rid of all the water!

Andrew (Dangerous Goods Safety Advisor,amongst other things)

 

[devonwoody]

If the tank was replaced under warranty, you then have a new warranty of at least 12 months on the new tank.

And if they play up, tell them their product could explode and they could face manslaughter charges :wink:

 

[Mcluma]

just welt it with the solder iron, scrap some of the plastic to the point you need it to get it stronger, also rough it up with the iron so you can use other bonding agents that will stick to the rough surface,

 

[ike]

The tank will likely be an oleofin (waxy) plastic - polypropylene polyethylene (HDPE). Lashing rope is polyprop, you could use the strands as filler.

Don't worry about using a blowlamp except a pointy little flame is best to keep the heat localised. But you MUST fill the tank with water and it will be perfectly safe. Nothing to lose by giving it a go even if you end up with a lumpen mess. :wink:

cheers,

Ike