Flooring advice

[Blueline93]

Getting ready to put the flooring in my boat but I’m kindve stumped on what to use. The rebuild has been pretty much done with composites and id like to keep it that way but with the price of coosa it seems a little outrageous to spend 3k on flooring. Anyone have a suggestion or replacement composite that I could use, that would also support a tower being bolted to it as well. Thanks

[dmont]

I am a fan of honeycomb panels. I used 3/4" carbon core honeycomb on mine. It was about $75 a sheet, but that was over a year ago. All of the honeycomb panels are about the same (nidacore, im sure there are others.) Find a local fiberglass products place and buy from them, or get a fiberglass/marine shop to order it from their supplier. I buy from Advanced Plastics.
Where you have the legs of a tower coming down, you either need a stringer/bulkhead under the leg, or you will need a piece of aluminum plate glassed in on the underside. You would basically sandwich the honeycomb material between the aluminum plate below deck and the plate on the leg of the tower. Just know exactly where the plate is on your deck layout. You could tap the aluminum plate below deck to accept a bolt. Just make sure the plate is thick enough to give you plenty of threads, probably 1/4" minimum or double up 3/16".
There are other ways to do it, hopefully someone else will give you more ideas.

[dbiscayne]

I'm using Plascore brand honeycomb panels w 2 layers of 1708 on the bottom and (1) 1708 plus (1) 12 oz cloth on top. Be sure to get the honeycomb with the veneer on it so the glass sticks better. When doing the layup I also laid visqueen on top of the glass then flat plywood then weighted that down to compress the glass better. Not exactly vacuum bagging but it does leave a nice flat surface and I've tested some samples doing this and can't rip the glass off. In areas where I needed to screw anything down - console, helm seat - I glassed coosa board to the tops of the stringers to hold the screws.
With that said, if you prep 1/2" plywood correctly you'll get at least 15 years out of it, maybe more.

[wingnut]

Price out Divinycell H80, which is a foam board without glass in it... You have to glass it a little heavier than Coosa (and definitely glass the underside), but it's a dream to work with and you end up with a very lightweight sole.

CSM on the underside and two layers 1708 top ended up being extremely sturdy on my rebuild. If you properly reinforced the area where the tower feet will go, it would definitely work.