How thick is your floor?

**FUJIMO** · 06-20-2021, 07:50 PM

...i glass in 1/2'' aluminum that was tapped for fine thread hex-head seat bolts/washers. no problems...only solutions...

**CUDA** · 06-20-2021, 09:13 PM

Yep

This is the boat that's built lighter than you would ever believe...

a Sunday stroll

**FUJIMO** · 06-20-2021, 09:50 PM

**tnelsmn** · 06-20-2021, 10:52 PM

1/2" marine ply. 1.5oz CSM on the underside, 2 layers 1.5oz CSM on the top. Floor is rock solid. Also has two stingers under it.

**David - WI** · 06-20-2021, 11:16 PM

Originally Posted by Pulse186

A flexy floor to save 30 pounds or a solid floor to not save 30 pounds, personally I don't think the boat will be faster or slower either way. But I plan on buying an aluminum anchor and a manual set back jack to save weight on my progression so what do I know, lol!

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#.

**ADDvanced** · 06-21-2021, 03:08 PM

Interested in learning more about nida core.... but again... finding a supplier in the midwest is super challenging. Anybody know of any?

Total plastics can get me coosa, so that will happen.

**LakeFever** · 06-21-2021, 03:16 PM

I’m using 1/2” coosa. Was going to leave the bottom bare and do a couple layers of csm on top with two stringers underneath

**FUJIMO** · 06-21-2021, 03:26 PM

...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.

**ADDvanced** · 06-21-2021, 03:39 PM

That can't be true tho, because if moisture gets into a plywood floor, that fiberglass skin sure sinks and the floor acts soft.

The thing about nidacore is that the main surface is a synthetic non-woven fabric, which absorbs resin and forms a giant bonding surface.

I have called a few suppliers in the midwest, and none of them have anything like this; they will have a honeycomb panel with aluminum faces, or a recycled cardboard honeycomb panel (which would turn to mush if moisture even looked at it).

I cannot find anything that offers the weight advantages of a synthetic honeycomb that is finished with a surface that will adhere to resin.

**FUJIMO** · 06-21-2021, 03:48 PM

...use closed cell foam core...any brand you can get. all the world & national championship boats i've built were bagged, but when glassed in a standard fashion, the quality of the finished product is excellent, just very mildly heavier on resin content, which means nothing on a pleasure boat.

**FUJIMO** · 06-21-2021, 04:36 PM

Originally Posted by ADDvanced

That can't be true tho, because if moisture gets into a plywood floor, that fiberglass skin sure sinks and the floor acts soft.

...i have'nt used plyrot for coring in a floor panel in 25 years...i'll take your word for it...

**David - WI** · 06-21-2021, 04:52 PM

The core has to have some compressive & shear strength.

https://netcomposites.com/guide/core-materials/

**Pulse186** · 06-21-2021, 04:57 PM

Originally Posted by ADDvanced

That can't be true tho, because if moisture gets into a plywood floor, that fiberglass skin sure sinks and the floor acts soft.

Not even that, what about a transom and stingers. If the wood rots they are toast. The entire structure has to be engineered from the get go where the glass is the structure and the core only the initial support. That obviously isn't done on smaller boats like ours.

**HydroSkreamin** · 06-21-2021, 05:43 PM

When I was revamping my Eliminator, I experimented with different thickness plywood, and found that 3/8" marine plywood with one layer of 1808 on both sides was extremely strong.

You could take the bare 3/8" plywood and put a square across two flat surfaces and it would snap in two when you would stand on it, but with 1808 on each side, I could put my (then) 200 lbs on it no problem. I took 3/4" plywood out and replaced it with the 3/8" plywood/1808 combo, and it's strong. There's also bulkheads every two feet, and the stringers reach the floor, so the spans are very small as well.

If I was doing it again, I'd probably spend the coin and do 1" foam with 1808 on both sides, probably make a plate with studs hollowed out in the middle, router a spot for it in the bottom of the foam, and glass it all up. I've spent some time rigging in a 47 Outerlimits and it's amazing how much foam is in those things, and there's a reason they're as light as they are, but still take the waves. The floor was 1" foam in there, and it's an older boat. No issues that I could see.