My Haven 12 1/2 calls for white oak deckbeams with a crown of 1 1/2" over 5 feet. I have cut the beams on a bandsaw leaving a little extra beyond the marked lines. I was wondering what the best way is to get a nice even curve which is the same on each beam? Should I clamp them all together and use a longboard on the upper convex curve? What about on the lower concave curve?