FS19 deck question

[bwhite829]

Hey all. Eventually I'm going to pull the trigger on the full boat build. I think I'm going w/ the FS19(I got plans for GV18, and have thought about XF20, LM18, and others but I think the FS19 will fit my needs the most). I am going to deck the first 8 feet, as well as a full walk around deck about 12" wide around the whole boat and about a 2 ft rear deck. With all of that decking, I realize the added weight would be substantial. I'm wondering if framing it in with marine ply and glass and then making the actual decks/hatches w/ nidacore or another composite would save enough weight to be worth it?

[Fuzz]

Nidacore is not much more than good marine plywood but you will need a bit more glass so that will drive the cost up a little. Depending on how big the unsupported aeries are you may not need a lot of glass on the nidacore. To keep it from flexing the bottom layer is more important than the top layer is. But you still need enough glass on top for puncture resistance. All that said I really like the nidacore for decks. I used 3/4 but one inch is not much more cost or weight and the next time I will use it or even thicker.

[BrianC]

...All that said I really like the nidacore for decks. I used 3/4 but one inch is not much more cost or weight and the next time I will use it or even thicker.

So what is it specifically about Nidacore that makes you prefer it over plywood for decks?

[Fuzz]

On smaller boats where 1/4 or 3/8 plywood is enough I might go that way. For larger boats where you need to span greater distances the nidacore can save a bunch of weight. Decks are its best use, dealing with the raw edges for other things is a pain. It has its draw backs just like every thing does. If you need to screw stuff to it you have to either put in a plug or some form of backing. In larger commercial fishing boats 1.5 and 2 inch nidacore has become the go to stuff around this neck of the woods.

[bwhite829]

What is the expected weight savings if I were to compare 1” nidacore to 1/2” ply?

[topwater]

One layer of 12 biaxe on each side of 3/8 ply is as strong or stronger than 1/2 ply. How big of a unsupported span
are you going to go If you plan out your under deck support correctly you should not need 1/2" ply for decks.

[bwhite829]

One layer of 12 biaxe on each side of 3/8 ply is as strong or stronger than 1/2 ply. How big of a unsupported span
are you going to go If you plan out your under deck support correctly you should not need 1/2" ply for decks.

I think the biggest span might be 4x2 or 1x6 for live well or rod locker.

[topwater]

Just plan out for deck supports and use thinner ply. All decks on my boat are 3/8" ply with 1/2" backing plates for
all cleats and rod holders . The only glass i used was 10 oz cloth for abrasion resistance. Do a search and look at
how others have laid out their hatch and deck supports. It will also save you some weight.

[TomW1]

Follow the plans and use the 3/4 inch cleats as called for in the plans. A layer of epoxy on the bottom and a 12oz layer on the top should be plenty. If you make larger compartments then do 12oz top and bottom. A 2x4 or 1x6 double coated should be no problem.

Tom

[Browndog]

The only place where the decks on the FS 19 seemed a little soft was in the area directly over the below decks fuel tank in the area of the inspection plate that I could have reinforced more by putting a layer of fiberglass under the deck in that one area. Once the leaning post was installed, that area stiffened up some.

Now that I have about 8 hours on the motor and several days of using the FS 19, I would say that the cockpit deck is about right as designed as far as thickness. Although I raised the deck one inch, in retrospect I should have raised it 2 inches because of all the weight that I added to the boat. Raising the deck would make the scupper issue better and would also have made it easier to put in the fuel tank.