Wingfoil board 160x60 70 lt

[nemoz]

Xps core 2 fiberglass layers 6 ounces at top and one on the bottom, carbon patches around straps area and boxes area and 8 mm eva pad.

[Dave_H]

Very impressive looking build! I've got a couple of questions if you don't mind me asking:
1. What density and brand of XPS did you use?
2. What were the dimensions of the XPS block you started with?
3. Did you take any special precautions to prevent delamination/bubbles down the road with the XPS?
4. How much did it end up weighing?
5. Would you do anything different?
Thanks.

[nemoz]

xps is 35 kg
the block was 2500 600 150
belamination with XPS ... well just to let you know i started using XPS in 2010 for surfboard, in 2009 in europe we had a new law and basically the xps sold in our region don't have to emitt any gas even at high temperature, I know in USA and Asia is not the same, so if you buy it from a european company you will have no issue, obviously if you are using good epoxy, i had only one dalamination issue, but it was my fault, i was in a hurry, i laminated a dark grey board, and i let the board curing outside, it was a warm day but pretty cloudy, 30 degrees basically no sun, well at 1 AM the sun came out and the resin was not perfectly cured, at 2 pm there was a big delaminated bubble at the tip.
talking about weight i have no clue, but i used a pretty thick 10 mm and high density heavy eva pad i had at home, i can weight it later.
it was my first wingfoil board for my first try... i'm a good windsurfer and a good kiter, well for the first 90 minutes, i wanted more volume and a wider board(I'm 63 kg and 70 liters for a beginner was absolutely not a good idea), then i found a mixed starting tecnique between the normal on 2 knees and the sinker one and from that moment i'm fine, i start with front foot in the starps and the back leg on my knee.
Anyway wider board 70 cm help a lot with stability during the start, my next one will be used in lighter wind, so i will go wider and with more volume, around 80-85 liters. i'm used to design the board in boardcad first(some of the cnc cut, others hand made) if you want i can upload the file here.

[Dave_H]

Nemoz, Thanks for the great information, I did not know XPS material property requirements varied by country, that's good info to know. It is also good to hear some success stories with XPS as it has some superior properties. I had used a similar density XPS from Dow for a surfboard years ago and did not have any delamination issue with it for the couple years I had it either, but it seems like there are many builders who have experienced issues. I really roughened up the core after I shaped it and used an epoxy with high adhesion properties which may have helped. I have two pieces of 51mm thick XPS left over in the garage that I was considering gluing together or combining with some EPS to make a thicker blank for making a wing foil board out of. It is going to have to have a fair bit of volume to float my 82kg in our typical light wind conditions, so I am wanting to make it as light a practical. I will probably shape it by hand as I don't have easy access to a CNC.
Dave