- Used a 2-3/8" Mikwaukee Hole Dozer hole saw to cut a hole in a piece of scrap 3/4" plywood. Did my best to make sure that the drill was vertical. This bit of scrap will serve as a guide when drilling the vent hole in the dorade box.
- Cut a piece of scrap 2"x4" to fit inside the dorade bit. The 2"x4" is a bit thicker than the inside hollow of the dorade box. Will place this scrap inside to dorade box when I drill the vent hole so that the inside surface is supported and so that the box is clamped between two pieces of wood and not clamped to the work bench.
- Checked that the hole in the scrap 3/4" plywood was larger than the "neck"(?) of the vent. Vent has about 1/16" space all the way around inside the hole in the scrap 3/4" plywood. That's a reasonable size. The next smaller hole saw, 2-1/4", might not have made a large enough hole given the irregularities of the vent's neck(?).
- Placed the scrap 2"x4" inside the dorade box and placed the dorade box on the work bench.
- Aligned the scrap 3/4" plywood guide with the pilot hole in the dorade box.
- Clamped the the scrape 2"x4", the dorade box, and the scrap 3/4" plywood together.
- Slowly drilled the 2-3/8" hole in the dorade box created a lot of fine fiberglass dust. Protective goggles and Full Face Respirator
highly recommended. The fine fiberglass dust stayed within the guide hole as I drilled. Stopped a couple times to removed the dust so that I could see the work.
- Turned out rather nicely. The clamped wooden pieces supported the dorade box and guided my work in drilling the hole. No damage to either the top or the inside sufaces of the dorade box.
- Sanded the inside of the vent hole and the inside of the dorade box at the vent hole well to remove any fiberglass slivers that might remain.
- Cut blank is between 1/4" and 9/32" thick.
- Lightly sanded the outside of the dorade box and wiped down well with a tack cloth.
- Applied the third coat of Rustoleum white protective enamel.
- Time for a cold shower and change of clothes to remove any stray fiberglass dust.
