How to best fit wooden trim panel to GRP wheelhouse sides.

[Leighb]

Our new boat - Storebro Biscay 31- has a solid mahogany trim panel on either side of the wheelhouse below the windows.

I have removed them to clean and revarnish. When I removed them I found that there were plastic washers 2-3mm thick fitted over each screw between the wood panel and the GRP. These had been liberally coated with brown “mastic”.

I am seeking advice as the the best way to refit, the thin gap that was there seemed to trap dirt damp and algae and I feel it would be better to fit the panel directly to the GRP, perhaps with a clear sealant bead around the edges,?
What do forumites think?

Many thanks.

 

[Lon nan Gruagach]

Keep the gap and seal the edge with mastic, it is easier to "key" the mastic in a gap than a corner.

 

[Quandary]

If the purpose is to keep the wood out of contact with the GRP to allow some air movement and control condensation thus keeping the back of the wood dry, I would be inclined to keep it but 2-3mm may not be sufficient, can it be increased a bit? Sealing round all the edges might reduce ventilation of the gap?
A thin layer of closed cell foam might be as effective as the air gap?

 

[bigwow]

Or if you wanted them removable use dual lock.