After a LOT of research, I have chosen Gurit's "Core-Cell" M80 SAN Polymer foam in a 3/4" (19mm) thickness. The plans call for 5/8" (16mm) thickness, but Ian says you can go thicker if desired. I chose the thicker sheets for the following reasons:
1) Primary use of the boat will be long distance cruising. I'm willing to trade a bit of weight in favor of a bit more toughness throughout the structure.
2) The Resin Infusion method produces stronger and lighter skins with increased flexibility compared to hand-laid materials. The thicker foam sheets will reduce that flexibility while providing a slight increase in panel puncture resistance.
3) Thicker panels should allow an easier and better vacuum integrity. (Henny has complained about that in previous posts)
4) Some light sanding before laying fabric and especially rebating the foam to allow for fabric overlap locations won't leave the core too thin in areas.
5) Slightly thicker foam means the screws have a bit more material to bite into when bending the foam into place.
6) The additional weight over an estimated 70 sheets (Hull sheet count estimate) will be about 184lbs (82kg). I guess I'll off-set that by getting on a diet... :)
As for the delivery itself... I don't really need the foam right now, but my Composites One Rep was telling me there are supply problems and it might take a while to receive the materials after ordering. In some cases up to eight weeks. With that in mind, I went ahead and placed the order - I wasn't expecting to receive anything for a month or so which would have been good timing. But it turns out the warehouse in Florida had five cartons on hold for a buyer. They contacted the buyer and he agreed to release a carton to me. So I guess it all worked out in the end. I'm still waiting for a couple of sheets of the High Density foam (M200), but that won't be in for another few weeks at least.
I'll be making a storage area loft above the bathroom this weekend to get these sheets up off the floor and out of harms way. I'll also keep the stock covered in the original cardboard box.
 |
| First Carton of Foam is delivered |
