hummm, lets see. I have seen a few boards painted out in the scene. I imagined you really need to prepare your surface really good for the paint to stick to it. Now this is just me thinking so I might be 100% incorrect.
this is from my painting experience
get the surface nice and rough by sanding the living crap out of it. then primer (let it dry the amount needed, this is a fatal mistake that many people make), then paint in 3 light coats, allowing drying times in between.
I would be very careful with the edges and the base of the board. I also would be careful of not sanding to much that would start to destroy important layers of the board.
Now I am not sure how they paint snowboards you say with silk, I would imagine that eventually your paint job will fail(after some time).
A few members painted their boards here, but to be honest I never asked how they did it.
Shit after witting all this crap , I decided to do a simple google.com search and found this,
How To Custom Paint Your Snowboard click there for the info you need to paint your board. Fuck all this time wasted for nothing
Remember google is our friend
Hey post a picture of the board, I wana see if it really looks that bad.