I suggest instead of trying to glue carpet in your board wells, (it's too thick and the boards won't fit when you are done) why not spend the $8 per side, ($16 total to do it right) and buy the pre-glued gasket strips from any Nacra Dealer. You can use the ones for the Inter 20 or F18. They are about an inch wide x 12" long and have a peel off strip on the back, already sticky, very easy to simply peel and stick in the well. You would want one for the top and one for the bottom in each well.

Yes, it might cost you a few more dollars than a "do it yourself" kit, but I'll bet the finished product works much better. It really sucks when you can't get your boards up or down!