This is one of two bits I use to remove the core. It is a 5/16" diameter head with a 1/8" shank. It allows a perfect amount of core removal to seal the deck from moisture.
I forgot to mention that later on I ground the 115 bit down to a shorter length to fit within the thickness of the deck. This worked faster than the 199 bit for clearing out material.
Jim
27-Apr-2012 14:43
My deck under the genoa track is about 1/2" thick total, and only a little over a third of it is core. The 115 bit is too long to create the cavity between the layers. Instead, I used dremel 199. It's 3/8" diameter but the cutter is only about 1/16" so it will make the cavity in a thinner deck. I also stacked washers on the shaft of the bit to create a depth stop (after going all the way through using the 115 bit). Because it's 3/8" diameter, I enlarge the hole from the bottom side of the deck. It's way more hassle, but it leaves the outer deck hole alone at 1/4".