Nidaplast Hardtop Laminating Schedule

[Tom S.]

I am currently building a DE 25, is it possible to get a laminating scheduled for building the cabin and hardtop from nidaplast as opposed to plywood sides and top? Including recommended core material thickness for each sides and top..

[fallguy1000]

I am currently building a DE 25, is it possible to get a laminating scheduled for building the cabin and hardtop from nidaplast as opposed to plywood sides and top? Including recommended core material thickness for each sides and top..

Most likely you'll need to specify the plans for the top. Walkable? Solar?

I have plascore on hand, but I found it easier to build the roof up which could also be done with nidaplast. What I did was made laminated curved beams, then screwed n epoxy glued 6mm plywood to them, then applied 12mm scrim foam and cut pieces of 12mm foam, then laminated 18oz over top. It was pretty easy this way as I did not need to laminate the bottom of the core and got the stiffness from the ply.

I went away from plascore because any roof penetrations would be a pita to decore and recore. All fyi

Hopefully Mertens will coin in for you as he understands the dimensions better.

I'd be glad to discuss further the cabin and roof of the Skoota. My cabin walls are mostly 12mm corecell with 1700 each side.

[Tom S.]

Thanks Fallguy I followed your input on Wes K roof framing and was seriously going to follow suit would just like to keep it light as I’ve over built on so many other areas.

[Fuzz]

Be interesting to know the weight of the hardtop now. As for is it strong enough I would test it. If you might need to walk on it go ahead and try it now. Might be best to get a small person first and build up to it

[fallguy1000]

I can easily calculate the weight of my roof.

But what matters is span. The wider the roof unsupported the stronger it must be built. I designed it for 100 pound point loading. I can walk it. My span is 8 feet. There is a supporting wall for the bathroom.

My roof weights are an estimate.

17 oz biax hand laid. -34 oz per yard plus infill of scrim and cracks say +4 oz per yard

Several lifts of fairing compound 10 pounds?

Gurit san polymer 5lb density

1/16" v trowelled thixo entire roof to bond san to ply

1/4" okume

Redwood laminated beams and glue above them

Double taped edges. So 2" perimeter x2 of 1708 and resin or 50 oz/yd perimeter at 4"

I can tally it all in a bit. Still dark out.

I can probably do a good estimate here.

Redwood. 26#/cuft. Each beam is 2.5" wide by 1,5" thick. Centers are a foot. So a full panel gets 7 beams. Each beam is 5.5# plus about two pounds resin to the ply. So 7.5#x7 or say 50 pounds; the resin is high at 2#. This seems about 10# higher than my gut
Okume is 22#
Gurit foam is 6.3#
Let's use 3 pounds of resin and thickeners. Pretty close.
8 pounds glass and resin
Fairing at say 3#

92.3 pounds
2.9 pounds per foot

The big advantage is I rated for 100 pound point load and my roof is round, so laminating plascore would have been a bear/required mould.

[fallguy1000]

I don't know how Nidaplast stacks against Plascore for rigidity or flexural strength.

If my roof were made from plascore and nothing more; it would be pretty flexible. I wanted to be able to withstand some snow loads.

My aft cockpit is made from plascore. It is two layers of 22oz triax laid two directions bottom; one top. Hand laid. It is pretty strong to walk on, but would have been a bitch to plug and mould to glass 44 on the bottom. Span is 53", well, actually 51" by 86". It does bend, but me and Mrs stood on it and it didn't creak. Sagged a bit. Still considering another angle iron, but she is getting heavy aft. Not my wife.

The plascore is 4# density; 3 layers 22 oz is 66 plus plascore is resin thirsty and uses about an extra quart for a panel this size each side, so 66 oz per yard plus fixed 64.

Panel is 11#.
3.6 yards times 132 oz plus 64 is about 34 pounds. Plus say 3 pounds fairing
48 pound panel
1.5 pounds per square foot.

Keep in mind the edges must be wrapped for a roof, so that will add same like my 50 oz at 4". When I do the calc of my roof, I will skip that.

[fallguy1000]

Also, two layers of 6mm okume is 42# plus say 3#tobond. Plus 6oz woven on top at about 3# more is 48# as well or the 1.5...

[Tom S.]

I am currently building a DE 25, is it possible to get a laminating scheduled for building the cabin and hardtop from nidaplast as opposed to plywood sides and top? Including recommended core material thickness for each sides and top..

[jacquesmm]

The specifications for a foam sandwich superstructure are on the construction drawing D271/3.
I see them somewhere in the middle of the drawing.
I specify Divynicell as a core but you can use Nidaplast.
Nidaplast like all honeycombs will require more inserts wherever you install hardware of even windows. It has a glass veil to limit resin absorption but still, it will soak in more resin than foam unless you use a skin coat.
Anyway, the specs are on the plans.

BBC sells Nidaplast as finished panels. That eliminates the resin problem but those panels are very stiff, you can not bend them. They are fine for the sides, not the top.
If you use those for the flat panels, there is no need to add the glass I specify on the plans since they are already fiberglassed.
I love those panels for soles and bulkheads.

[Tom S.]

Your correct I totally missed it. Thank you.
I do see two thickness there listed for divinycell, is that just a nominal number vs actual thickness?
And yes I would love to do a second build with nidaplast sole. Bulkheads are something I never even thought of.
How much ( rough percentage) weight savings do you think between plywood and foam / honeycomb pilot house and top.