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#1 Fuel tank gaskets suitable for fuels with ethanol in.
Posted: Sun Jan 09, 2022 8:00 pm
by johnetype
Given it's not recommended to use cork gaskets with ethanol*, does anyone know of an alternative supply for C22226 and C937 made out of a material appropriate for modern fuels that have some % of ethanol in them such as neoprene?
*
www.fbhvc/fuels
#2 Re: Fuel tank gaskets suitable for fuels with ethanol in.
Posted: Thu Jan 13, 2022 1:07 pm
by militateormitigate?
Hi
looking at the gaskets pictured on the SNGB website, they have the appearance of being made of 'rubber cork' i.e. a bonded composite of nitrile (NBR) and cork granules. A pure cork would not have the black speckling (the nitrile) in it.
So the nitrile rubber would provide resistance to ethanol (it's used in R9 spec ethanol-compliant hoses) whilst the cork would retain the ability to compress down evenly within itself, between the flanges under light bolt loading. A pure rubber gasket would displace itself and the mounting bolts/screws likely slacken off over time.
Of course SNGB or other suppliers should be able to confirm the material, it's just that I'd be surprised if they were pure cork judging from the photos. I've got sheet of pure cork and the composite type in the garage for DIY gaskets and the difference is easily apparent.
So I think it's worth checking it out - and good luck!
Alun
Northants
S2
#3 Re: Fuel tank gaskets suitable for fuels with ethanol in.
Posted: Tue Jan 18, 2022 8:13 pm
by mark10337
A reputable supplier to a reputable restorer replaced the one on my SII tank top cover with a non-cork one that was "ethanol safe". It melted within 3 months, worryingly at the petrol station when I filled it to the top resulting in petrol pouring out of the seal into the boot and out near the exhausts.
I replaced with a cork a standard cork from SNG and all has been fine since.