Polyester resin cannot be used with EPS or XPS foam cores.
Swaylocks Surfboard Design Forum: thoughts & theories ... practical & theoretical
RAIL PROFILE http://bgboard.blogspot.com/2014/03/march-82014-afterr-seeing-recent.html
You can turn any density foam into 0.75lb or less with very little effort. Don't have a formula, just a router with bit, two turn tables and a microphone.
Looks like you glassed one side before routing.
How did you glass the other side without getting sagging over the air pockets?
Rout from bottom and try not to go through deck. Leave 5-8mm. perfect job for a cnc machine versus me.
First pic is a blank I made in 1998 or 99. Open cell eps 1.8 lb density. Almost threw it away dozens of times over the years. Totally was belly laughing at what the open cell beads do to you and your shop when you cut it. Blast from the past. Should have taken a pic of the havoc. Still better than PU of the day though.
Second pic to answer your second question. Hardwood planks. Tried this with balsa 1/8 stiff planks about 12 years ago and it was cool but dimpled in all the recessed areas. Gave it up as a bad idea until I finally got my paulownia import permit to try it again. Started board 5 yesterday. Getting it down. Paulownia is 2-3 times denser than the balsa I stock.
all the best
Personally I'm always ready to learn, although I do not always like being taught. - Winston Churchill
I am familiar with the JQ and I think the heavier version would ride better - go for it!
Charlie, you're a freak.
Just clap your hands.