From freecarve.com, written by PSR:
At the end of the season(ours in the Northeast is almost done),I put my boards on a camber rack for the summer.This helps boards hold their shape,both in terms of camber,and in terms of twist.It's fairly easy to make,using 2x6's,and 1" wood dowels,roughly 1' long.Each 2x6 gets five dowel rods,one at the center(centered in regards to length and width,draw a lengthwise centerline for reference),and two each at the ends.I cut the length of the 2x6 so that it's +or- 6" longer than the boards that'll be mounted on it.The dowels at the tip and tail of the board are placed 2" inboard of the nose/tail curvature.Space the end dowels so that there's a gap of 1/2" between them(3/4" from centerline of the 2x6 to the center of the dowel holes),and that one dowel is directly above the other,with regards to the centerline.The dowel placement should look a little like this, : . : but with the center dowel up to the true midpoint of the 2x6.Small shims can be used to cure any gaps(Asyms are a challenge!),or to set the right camber for a given board,And paint-stirring sticks are ideal here.Set your boards base-to-base on the rack,matching lengths whenever possible(try to stay within 10cm of difference between any two boards on a rack),and shim only enough to keep the current camber,as a thick shim can actually stretch a board's camber over the summer.Store your boards in a dry,tempature-stable area,away from direct sunlight(most garages are o.k.).Don't forget to wax them before storing,and be sure to cover the edges with extra wax to keep rust at bay.I hope this helps the more serious riders keep the quiver in shape during the off season.Gotta run now,as my boards(15 of 'em,Oy) are due to be put up for the season.Ah,the smell of wax...