How large an area are you talking about? You mention in the post going from the companionway forward. I can't fathom doing that much core work from underneath.
All of it.
There is no paint on the deck now, just gelcoat and I'd like to keep it that way, the outter shell is in good condition and I really don't want to hack it up if I can avoid it. The inside liner is cracking severly and coming apart, mildewed and rotting.
I guess my other question (which I've asked on a Merit site) was the thickness of the core. It looks to me like 3/8" plywood, I'm assuming I could use 3/8" end grain balsa to replace this correct?
jbondy, I plan to use adjustable "hood props" that some mechanics use. Basically a telescoping pole that can be locked into place. If those don't turn out to be cost effective, then wooden dowels cut to length will have to do.