When shaping a concave(teardrop)in longboard noserider bottoms, what is the appropriate method after pencil outlining the area to be removed to achieve a inverted arc without flat spots(when the tooling is not curved also)?
This is what I’ve found works quite well. After penciling in the area to be concaved, tape outside the line a 1/16th". Now is the time to determine the curvature of the center line, most teardrop type of concaves are nearly a straight line from start to end. Carve out this area with the planer, shallowing the cuts to the outer edges. Finish off with your surform if necessary, I made myself a series of concave sanding blocks with varying degrees of curvature that I use to finish off the concave with. The masking tape has kept the concave from growing outside the lines that were first drawn. With the fine screen on your sponge pad, fine sand the concave, pull up the tapes. If you are planning on pinlining the concave leave the pencil line, if not, lightly screen the area again with the sponge pad and erase the last of the pencil line. Your done.
This is what I’ve found works quite well. After penciling in the area to > be concaved, tape outside the line a 1/16th". Now is the time to > determine the curvature of the center line, most teardrop type of concaves > are nearly a straight line from start to end. Carve out this area with the > planer, shallowing the cuts to the outer edges. Finish off with your > surform if necessary, I made myself a series of concave sanding blocks > with varying degrees of curvature that I use to finish off the concave > with. The masking tape has kept the concave from growing outside the lines > that were first drawn. With the fine screen on your sponge pad, fine sand > the concave, pull up the tapes. If you are planning on pinlining the > concave leave the pencil line, if not, lightly screen the area again with > the sponge pad and erase the last of the pencil line. Your done. THANKS, YOU ARE EXTREMELY GENEROUS IN YOUR INFORMATION AND I CAN UNDERSTAND YOUR WAY OF COMMUNICATING IT. DO YOU FEEL ALL LONGBOARDS SHOULD HAVE CONCAVE IN THE NOSE(EVEN NARROWER ONE’S, SAY, 17")? ALSO DOUBLE CONCAVES IN THE LAST THIRD SUCH AS THE BONZER(OR LESS EXTREME) IS THAT TAKING SOMETHING AWAY AS WELL AS ADDING TO A BOARDS LOOSENESS? I SAW A PRODUCTION SHAPER DO NOSE CONCAVE WITH A PADDED DISC SANDER ONCE(HE SHAPES ABOUT 5-8 A DAY)TO REDUCE TURNOVER TIME, TOO SCARY FOR ME THOUGH(1 A MONTH!) THANKS AGAIN!!!