Definitely does not work.
Rephrased— it will work for a bit and then the mast will push right up thru the deck.
Or break in half.
This isnt new science. Weve been trying to make a hard board with soft rails and smooth skin surface for years —so weve tried it all.
Check out the thread “the fastest animals in the water are soft”
There is no reason to take a huge risk of being stuck in the ocean paddling in a broken board with a foil attached.
$900 ish is a good investment in a board you can believe is strong — and surfs, kites, and foils all disciplines.
This is exactly the mission weve been on for over 10 years.
Just spend the money on a good board (theres a few good shapers making great boards) and avoid the stitches and concussion treatment doctors bills.
Also—- i agree that foamie will flex like crazy. Stiffness is necessary on a foilsurfer.
And dont go too soft on your deckpads either. Eva pads diffuse energy when you push on them. Just keep them thin. Our soft shell skin is only 1/8” and wouldnt recommend higher than 1/4”. We use waxmat traction which is ultra thin and goes well with Cush skinned boards.
Flex is huge.
But Soft pads are not such a huge issue.
Just worth mentioning.
If you search around the interweb, there's been posts of people attempting to mount a foil on boogie board or soft top wavestorm style boards. Doesn't seem to work, not enough strength to hold the foil is my guess.
But for a regular surfboard, it's easily done and it works fine. Cheapest/easiest route is to do through hulls: either glassing in graphite tubes (golf club shafts) or forming epoxy tubes you drill through. You will ideally want some kind of plate on the top to spread the load, I've used a plastic cutting board. But best route is to install two mast tracks, this is less hassle to connect the foil and also makes the board more useful as a surfboard if you wish.
There's lots of old boards around, so this can be an inexpensive way to get onto a foil. The main problem is most surfboards, or even kite surfboards, are bigger than you'll need for your foil once you're expert. But an advantage: if you want to travel and plan to both surf and foil, it can be a 1 board solution. This worked well for me for a trip to maui last year.