Hello all,

I thought this question was best for the classic forum as it is "wood related"!

So...

Currently working towards getting the inside of a steel boat (Tom Thumb 24) spray-foamed.

Our current thinking for the hull fixings is:
1" thick insulation therefore will have battens or blocks about 2" thick to leave a bit of an air gap and allow for thicker bits of insulation (e.g. over stringers)

would prefer to stick battens/blocks to the hull with polyurethane sealant (Sikaflex type stuff) to minimise the amount of welding and metal bits sticking through the insulation, so if wooden they need to be non-oily.

battens/blocks must need very little maintenance as they'll be partly buried in the foam

they must be soft enough to screw into them to attach the lining and interior fixings.

Seems like some kind of hardwood will be best to cut down on the maintenance - can anyone suggest one that's non-oily and you can actually screw into. Any other suggestions welcome.

Thanks in advance for any advice.