question Sealant for petrol leak

[fv1609]

We've discussed these sealant fluids that are swished around the tank, particularly useful where there is widespread corrosion. But what I am after is some reliable sealant to block a tiny seepage from a definable crack, that could be applied externally to the defect.

 

I removed the tank some months ago & had it steam cleaned. The base of the tank was a replacement & braised on. After the cleaning the base looked in very good condition.

 

The seepage I am getting is visible from the crack between the arrows where the boss has been braised on. It is very slow it takes about 10 mins before it is damp to the finger, so I am hoping that there is some sealant that would set quickly enough.

 

It is a bit of a fiddle getting the tank out of the Shorland & I am scared of brazing with risk of residual vapours. Even if I used the gooey fulid & swished it around it would land in the boss & drain plug making drainage impossible.

 

Anyone got any recommendations please?

 

[rambo1969]

How about filling the tank with water whilst brazing it?

[Tony B]

One way is if you have an old CO2 fire extingusher, flush it out with that. Petrol is only explosive within certain levels of vapour. If the tank has been washed out and left open to air, you should be all right. Blowing plenty of cold air from air compressor can flush out the last of the petrol. If you can still smell petrol in the tank be wary.

[Marmite!!]

How about filling the tank with water whilst brazing it?

 

The smallest amount of water will take the heat away... no heat no brazing...

[Guest catweazle (Banned Member)]

How about filling the tank with water whilst brazing it?

Rambos hit the nail on the head Clive.turn it upside down seal it fill with water to just below the drain plug and off you go,i had to do this to the champ when the drain plug wouldnt move and it cracked the solder around the insert.CW,

[rambo1969]

Can't take credit for it, my dad used to do it when he had his lorries on the road.

[fv1609]

Well Darren (of Lux 101 & Striker fame) has saved my bacon & hard soldered the boss.

 

As an additional precaution I surrounded the edges of all this with the sealant Lee sent me. In addition I built up a rim of this on the inside to seal leakage to early rust of the tank base to the boss.

 

After allowing it to set for 4 hours in the sun, I have put a gallon of fuel in & after another 4 hours could detect no leakage. So it goes back in tomorrow.

 

I has been a good opportunity to re-route the fuel spillage/overflow drain. seen here is the fatter tube.

 

 

Unfortunately see were it flows to :shake:

 

Edited May 31, 2009 by fv1609

[Guest catweazle (Banned Member)]

But did he fill it with water before soldereing?or did he take other precautions.

[fv1609]

pm sent, the other precaution I took was to move the fuel overflow from dripping onto the exhaust!