AJS & Matchless Owners Club

Only Werther originals, nothing else compares! As for sealants I agree with Dudley!

spookefoote1956 wrote: So the judgement is that sealant is a load of rubbish, don't waste your money on it and it should be removed from the market asap and buy some Werthers Originals (other chewy toffees are available).

Perhaps even Chewing gum. That old dodge could still get you out of trouble if you spring a leak on a run at a rally etc.

So the consensus is don't use the stuff to re-line the wife's Cub tank? Because it will...............................?

I would use it if you need to, only you can really determine that with the tank in front of you.

The early sealants were little more than fancy fibreglass resin which is why they are now giving a problem with the change in the composition of the fuel.

agree with Duncan if its leaking seal it , if not just use it

g80csp11 wrote:agree with Duncan if its leaking seal it , if not just use it

Each to their own I guess. Sealant is a bodge, In using it you know life expectancy is ???. Not as long as a metal repair that's for sure. I have a sound 1915 tank. Leak proof for over 100 years so far.

Ethanol will eat into metal. Sealants are a lot better than they used to be. I've had two tanks braised and on the second the skilled engineer said he'd advise sealing it too. I used (after a huge amount of reading up) POr15 Each to their own. I'll keep sealing where necessary for the time being. Happy days.

Hi All, the problem with modern fuels is, as has been said, that they contain ethanol. This is not corrosive in its own right, but it is hygroscopic - absorbs water from the atmosphere, which then causes rust which may eventually corrode right through. Ethanol content will soon, if it hasn't already, rise to 10%, worsening the problem. I have just lined one tank, and will do so on another when I get round to painting it - it has recently 'pinholed'. This should hopefully future proof them against probable further increases in petrol ethanol percentages.

uktom77 wrote:Ethanol will eat into metal. Sealants are a lot better than they used to be. I've had two tanks braised and on the second the skilled engineer said he'd advise sealing it too. I used (after a huge amount of reading up) POr15 Each to their own. I'll keep sealing where necessary for the time being. Happy days.

I'm not sure about that. What ethanol will definently do is attracted moisture and raise the amount of rust causing dihydrogen monoxide to collect in the tank. It will also eat basically any soft rubber like compounds including nitrile rubber, phenolic gaskets, and polyester resins (fibre glass).

POR15 does a good job resisting ethanol and inhibiting rust but will eventually lose the battle against it. The higher the ethanol content in the fuel the faster the damage is done.

AvGas / race gas is what you want if don't want ethanol

Not Sure what you're 'not sure about'? Seems you're saying the same thing, just semantics.

Presence of Ethanol speeds up corrosion of metal.

Tank sealant can slow down corrosion (depending on the one chosen).

This debate seems a little like asking 'what's the best oil'?


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