Stringer Trim Router Base Plate
Wood is hard. Foam is soft. It's really hard to use wood cutting tools on the stringer and not gouge and tear the adjacent foam. It rarely works out to a clean shape.
Since we tend to approach problems differently at Greenlight, we came up with a simple tool that is a quick and accurate way to get your wood stringers dead flat to the deck and bottom of your foam blank!
It is critical to get the stringer flush with the foam to avoid the fiberglass lamination "tenting" over the stringer leading to the glass quickly cracking and letting water in.
Traditionally the stringer has been cut with a trim plane and/or spokeshave tool. But these tools almost always gouge and tear the foam next to the stringer.
Simply attach this stringer trim router base to your Greenlight Router to Makita RT0701C and set the router bit depth to extend about 1/32" from the base plate.
Take a pass over the stringer on the deck and bottom and scrub the foam down to the stringer - Done. Dead flat intersection between the wood stringer and foam.
Watch how it's done in this video: