Anode with or without the washer

[SolentPhill]

Why do you buy some a anodes with a washer/ gasket and some without? I thought an anode should touch the metal it's attached to so why do some have this gasket?

I put one on my trim tabs today and it didn't have one.

phill

 

[David2452]

They can make a good electrical contact through the mounting bolts(s) even with a gasket, but they don’t really need one. A gasket can be useful if mounting through GRP for a bonded bar or similar.

 

[coreng]

Explanation : Anodes are more efficient when their plating does not touch what they are supposed to protect (legs). But for trim tabs, no importance...

 

[VicS]

I think the backing pad is only used when fitting to GRP or to wood.

 

[Surfacesub]

You may find this link helpful, for wood GRP substrate.

The closed cell backing pad is to control the Anode wastage and provide mechanical protection.

http://www.anodeoutlet.co.uk/fitting-instructions/wooden-and-grp/