Foam Core Deck

[Mist]

Mist will have a foam core deck.

I've performed a few tests to determine deck stiffness, toughness, and weight of various deck combinations. I chose to compare 1/4" Okoume w/ one side laminated 10oz cloth, 3/8" Corecell a500 w/ topside 10oz underside 6oz, and 1/2" Corecell a500 w/ topside 10oz underside 6oz. The 3/8" thick sandwich weighed half that of the 1/4" Okoume and was approx the same stiffness. The 1/2" thick sandwich weighed 25% less then the 1/4" Okoume and was twice the stiffness. As far as toughness is concerned, I dropped a 3 1/2# round weight for 3 foot high onto the samples. The weight went right through the Okoume and bounced off the 1/2" foam core. It took several drops of the weight to show a significant damage to the foam. Cost and labor is significantly higher for the foam lay-up and installation and the areas where hardware mounts will need reinforcement. I plan to use the 1/2" foam combination on the deck and the remaining sheet of 3/8" foam on the cabin top.

[micah202]

............VERY nice work

....maybe it won't squeek and flex like my one

[jerome]

looking very good indeed ! İ am surprised though that the weight you dropped went right through the plywood....

[admin]

me too...right thru like it penetrated the plywood such that you could see the bottom of the weight when you looked at the underside of the ply? Or, right thru such that the weight was lying on the ground after passing completely thru the ply?

if the latter, then I plan to be a lot more careful driving this puppy....

[Mist]

I'll provide more details this evening. The samples were 4" x 4" elevated off the floor by resting on two 3/4" thick supports. The weight hit the sample between the supports, in the middle. The weight cracked the plywood as if it wasn't there and hit the floor. The plywood is cracked and the only material holding the two pieces together is small remnants of the 10oz cloth.

[Chad]

The boat is looking great Tim!

Foam is lots of fun to use. For instance with ply parts, I feel like I shouldn't cut rabbets (or rebates, or recesses) for the local reinforcements, so fairing becomes an exercise in raising everything to the height of the thickest lamination. But with foam, all those added reinforcements can be recessed into the surfaces and everything is so much tidier that way- so much easier to fill a small valley, than to try to disguise a small mountain. Have fun playing with the stuff!