We’ve all been advised that any composite material of 20mm x 30mm and 3mm thick will do the job well, bonded to the mast preferably using epoxy (araldite rapid or similar would be perfect).
Its a very easy job just needing the mast down. It’s also great opportunity to service your diamond adjuster bolt… just remove the bolt, clean with a wire brush, and grease well using a waterproof grease.
To allow easy re-fitting, ensure you release the diamond wires from the upper mast tang to allow the slack in the wires to easily rebuild the bolt / Brass fitting, at the mast base end…
If you don’t have any suitable 3mm spacer material easily to hand, please contact your local dealer or you can order a suitable spacer, free of charge, from the Nacra Web-Shop using the link below.