How thick is your floor?

[HydroSkreamin]

So a layer of 1708 underneath I guess is now the plan. Think I need a second layer on top? Followed by csm?

I would refer to Fujimo's post (#23) above.

...again...its not about the core...its all about the glass over & under the core that determines the strength of ANY panel. generally speaking, the core, any core, should never be considered for strength or stiffness of a project. the core, no matter what it is, is just along for the ride, so it should always be a light core material. this goes for decks, stringers, transoms...anything. it gets glassed up in the same manner as cellulose, only the finished job is superior. its less important what brand it is, than the fact that you just use it, rather than cellulose. i would buy what ever brand & vender is the cheapest & the easiest to get in your hands. if you have to take a road trip, so be it.

The reason the double-biax has the strength over the CSM is the layers are intertwined. If you've ever wet any double-biax out, you'll see the strands moving feet away from where you're working; this is because those strands are continuous, and with the +/- 45º of the weave, once resin-infused, it's really strong.

When you put that material on both sides, it actually shrinks a bit when curing, and you put the entire part in tension. If you only glass one side, you get strength in one direction, but not the other.

Do the same experiment I did; take a 1' square and lay it up on both sides. Do another with just one side. And cut another and leave it raw. Compare all three after curing and see which one you'd want for a floor.

Unfortunately, sometimes budget dictates what material we use, and that's why us hobbyists turn to plywood. Covering both sides and all joints is a preventative measure to keep the wet out.

I can't give you a reference where I got these numbers, but I'm guessing from the Menard's supplier site (Roseburg) I ordered my marine-grade plywood through.

3/4"-72 lbs 4'x8' sheet, 2.25 lbs/sq ft
1/2"-44 lbs 4'x8' sheet, 1.375 lbs/sq ft
3/8"-31 lbs 4'x8' sheet, 0.97 lbs/sq ft
1/4"-24 lbs 4'x8' sheet, 0.75 lbs/sq ft

Even with one layer of 1808 on each side, you can see the 3/8" plywood is lighter than the 3/4" bare version.

Good luck! Try that experiment and let us know what you find.

[ADDvanced]

I already ditched the jackplate, built a carbon fiber ski pylon, bought an aluminum anchor, lightweight gas tank and 4# lithium batteries. I would give your left nut to save 30#.

What'd you do for your floor? Ply or foam?

[ADDvanced]

Ordered a sample box....

https://www.carbon-core.com/

Excited to see what comes in it, shipping was reasonable from this company and panel prices were less than plywood.

[David - WI]

What'd you do for your floor? Ply or foam?

The floor and the seat frames are 1/2" NidaCore with vacuum-bagged glass on both sides. Was planning to use S-glass but it seemed like overkill for a floor with such small open spans underneath. Front seat bases have aluminum discs welded on that are epoxied to the floor.

[CUDA]

down here
4x8 3/4 sheet

$72.00 to your door

[ADDvanced]

The floor and the seat frames are 1/2" NidaCore with vacuum-bagged glass on both sides. Was planning to use S-glass but it seemed like overkill for a floor with such small open spans underneath. Front seat bases have aluminum discs welded on that are epoxied to the floor.

Looks pretty good! Light/strong! Did you do the vacuum bagging yourself? And the seat bases..... so those discs are ONLY adhered with epoxy, no mechanical fastening? Is the disc just to increase surface area for the epoxy? Also, did you ever install carpet? Did you just slit it to go around the seat bases that a permanently adhered, or what?

[David - WI]

Looks pretty good! Light/strong! Did you do the vacuum bagging yourself? And the seat bases..... so those discs are ONLY adhered with epoxy, no mechanical fastening? Is the disc just to increase surface area for the epoxy? Also, did you ever install carpet? Did you just slit it to go around the seat bases that a permanently adhered, or what?

I vacuum-bagged it. Yes surface area, dics are sand blasted on bottom and epoxied down... no fasteners. No carpet, I used SEM tintable spray-in bedliner - I hate wet, stinky carpet - this I just hose out.

[FUJIMO]

[FUJIMO]

[Dave S]

HeeHee.....Bin Adddinnn Wet Soggy ....Fiber Floor.... for Years.......No need to ReCore...... Fell Thru the Bottom ....... Last time out.......... Hit My head on a Stringer.......gonna Sue.... Whgit Heads Splatter..........

[Dave S]

Nice work...............Ya think of alll these years of......Upgrades.......

[MattGreen]

The floor and the seat frames are 1/2" NidaCore with vacuum-bagged glass on both sides. Was planning to use S-glass but it seemed like overkill for a floor with such small open spans underneath. Front seat bases have aluminum discs welded on that are epoxied to the floor.

Count me in for another vote for a Nidacore floor. I came to the same conclusion for my Checkmate - 1/2" Nidacore with a layer of 1708 on each side. I weighed 4x4" offcuts of this and the original floor (1/2" fir plywood with what appears to be one layer of 0.8oz matt on top, and a light coat of resin on the bottom): 33g for the Nidacore, 49g for the plywood. You could get the Nidacore down even lighter by vacuum-bagging as mentioned. In my area Nidacore is also much cheaper than marine plywood

Matt

[FUJIMO]

...old video. but this is how quick & easy it is to do... https://youtu.be/vTnRmHV-TQI