gasket fuel tank inspection hatch

[catmandoo]

What material is now recommended for using with bio diesel ?
I used a nitrile rubber gasket two years ago and it is now tearing easily

 

[Talulah]

Cork gaskets.
i.e. http://www.stationaryengineparts.com/Cork-Gasket-Sheet-1mm-Thick.html

 

[vyv_cox]

There is a useful paper on this topic here. It seems that the only elastomer they recommend is Viton, the other materials not being elastomeric. Unfortunately, to say 'Viton' is equivalent to saying 'steel', there being many different types and formulations. The most common, and probably the cheapest, is Viton B, although this does not have the best chemical resistance. I would suggest you need to be looking for a hardness around 70 for a tank gasket. If you go much softer it could well creep badly, as the Vitons are not great in compression set. They are also not very cheap.

Cork gaskets are a mixture of cork granules and an elastomeric binder. Again, the elastomer needs to be resistant to attack by the fuel. This site lists cork gasket material with a Viton binder.

 

[tolhurstorganic]

Yes it needs to be cork material 4mm thick. Tek tanks sent me replacements after the neoprene gaskets failed after just one year.
See my post of August this year