Chapter 18: Constructing the Turtleback

Step 4: Contouring and Glassing the Outside of the Turtleback:

I found it extremely worthwhile to grind down the glue joins before contour-sanding the external foam surfaces.  The foam sands MUCH easier than the glue.  If you don’t remove the glue, you’ll end up with glue ridges (high spots) and unwanted depressions (valleys) in the foam around each glue join.  I used my dremel tool and a cutting wheel to remove the glue joins.  I then taped around the “channel” and filled it with pour foam.  Once cured, I held a hacksaw blade flush with the surface to remove the excess.  It is simply amazing at how easy and fast it is to contour the external foam.  I used a leftover piece of strake foam about 18 inches long x 6 inches wide and covered one side with 100 grit sandpaper.  The strake foam is flexible and allowed me to contour more effectively than a straight block.  I GENTLY sanded at 45 degree angles (NOT up and down!  NOT fore and aft!) until everything felt nice and smooth.



I built little sanding blocks from foam parts to get the proper depth and form for the fore, aft, and cut line depressions.  I stacked duct tape of the proper width until I got the right depth, then put on a corresponding piece of sandpaper held on with nails.   I covered the rest of the block with duct tape.  All I had to do was slide the jig over the foam until the proper depth was achieved.


I couldn’t round up any volunteers for glassing the outer skins.  So I rigged up two supports on my worktable to hold the roll of UND cloth.  I positioned the turtleback in front of the table, pulled the cloth from the roll, and simply allowed the cloth to drape into place.  Worked like a charm!  I couldn’t resist.  I peel-plied the entire outside surface.  My turtleback looks and feels like it came from a mold!  I am well-pleased and I think I smell redemption!!