Mounting a foil drive assist battery case on a concave deck

I’m looking to mount the battery case on the back of my One Ocean Sports 5’10” SUP foil board. Any suggestions on a tidy way to flatten the curve of the back of the board so I get a good stick with the 3M mushroom Velcro?

I’ve seen that scotty mac has mounted his FD box on his One board, but i can’t see how he has stuck it to the board. I don’t have any foot strap inserts to attach it to.

Why dont you 3dprint the difference concave=>flat bottom. It should be only below the velcro , so wont add much weight.

Btw, which velcro are you using? I first tried with some cheap strip i had, but i had to replace with the 3m duallock

I was considering making a 3d print to flatten it off, and glue it to the board with bostik isr 70-03. The weight will be minimal, it needs about 8mm in the middle, I just want it to stick down reliably. I have some of the expensive 3m dual lock velcro ready to go.

I printed a couple of simple spacers which fit the curve perfectly, glued with 70-03 to the deck, with 3m dual lock applied to the flat surface 24 hours later. All sorted. The 3m dual lock is some strong velcro, it was hard to remove the enclosure.

I had the same problem on my Armstrong board. Looks like it will work really well mounting lengthwise though! It might work for your board too?