I am shaping my first board (9’2" longboard). I have it roughed out and am going into the details. How do I achieve a very flat bottom from side to side all the way down the bottom rocker. Is there a specific technique, process or approach I should be using?
i have a plexi-glass board with glued on sandpaper. I put a level on top of it and stroke it down the board. you could also glue sandpaper to a level or a (level) straight and stiff board or angle iron. before i do this , i use a block plane to take the stringer down below the foam, because if the stringer is level with the foam, you will probably wind up shaping a little bit of vee into the bottom (so if you want a slight V on part of the board, using this method - dont plane down the stringer there). I stroke the bottom untill all the scratches are out - this levels the board to prep for bottom contours and smooths out any slight kinks in the rocker - a very good step in getting a board that looks smooth and deadly. However, this requires a pretty cleaned up and flat bottom to begin with - it wont take out huge mistakes
Thanks for the reply. How do you keep the foam near the stringer from getting drag marks on it when you plan lower than the foam. Is it just a matter of a sharper hand plane, do the marks always sand out, or something else?
i use one of those little block planes and it does drag into the foam, cutting the foam next to the stringer, but it doesnt go too deep, and after dragging that grit over the board, youll notice the drag marks will go away and the stringer comes flush pretty quickly (this method cuts the foam pretty well but doesnt do much to the wood stringer). Use a heavy grit, i cut and glued the loop for a belt sander.
Buddy, You can plane the stringer cleanly by doing a couple of things: #1: Use a good quality low-angle block plane (Stanley makes one) and learn how to get the blade razor sharp. It’s not hard to do right, but it’s easy to do wrong. When you run the plane down the stringer, hold it at a diagonal. It will slice much cleaner. OR #2: You can try one of those little block planes that hold a razor blade. I haven’t used one, but I know a semi-famous shaper who swears by them. Doug
Stanley also makes a “miniplane” that when set for a shallow cut will take down a high stringer without damging the foam. If it’s close enough, just glass it -glass and resin will fill and sanding takes care of the rest.
I agree with Doug.A sharp (razor sharp) low angle block plane at an angle .Probably the biggest problem beginners have is tuning and sharpening the plane itself.Another way is to use the electric planer held at an angle going slow over the stringer for the final pass.I then only take a few light passes with a foam block and 120 grit to clean it up.If you sand the foam too much the stringer will protrude.Good hand shapes are all about the electric planer,sanding blocks and surforms only good for removing tool marks. R.B.