Monday, 7 April 2014

Board Building Project - HD Creeper 48 - Stage 3 - Shaping the Deck

I am not one to rip into full length cuts using a plane, I prefer to mark out the rails and hotwire them. I like to create the hotwire guide lines from the CAD model and these allow you to remove the bulk of the deck roll and rail while maintaining a smooth flowing shape.  The faceted faces on the rail are then fine tuned with a sanding block with 80, then blended/rounded using 80 and then 120 grit. 

If you try to shape only sections of the rail to the finished profile you will end up in all sorts of trouble and it will show on the finished board - there will be really bumpy highlights and reflections.  I like to create construction geometry around the rail profile at various intervals along the length of the board.  Then I create some tangent lines at key angles and extend these to what would be the outline of the EPS block.  The position where the tangent line meets the block is marked and all the matching tangent - surface intersections are joined along the length of the board using the outline and rocker templates as giant french curves.  Using these curves also helps the volume flow nicely as you are using the same curves with which the outline was cut. You also need to mark the wide point clearly to allow the rail tuck to be shaped correctly.

So I went to shape the lower rails(below the wide-point) and found I had made a error on the tuck calculation - I allowed for the 3mm shell on the outline but not on the pre-cut 6mm Dcell on the Hull. I ripped off 3mm from the wide-point with the router, squared them up, re-marked the wide-point and re-blended the rails.  The Dcell hull was trimmed with my tuck template using a snap-off knife.   

Next was the deck concave which was originally going to be 3mm, I changed it to 6mm.   The mast track area steps down an even 2mm from the hot-wired deck.

Next up is smoothing the rough sand and fitting the deck sandwich.