To install a heater flue, I have to make a 5" hole through the cabin roof of my boat. The roof material is 1.75 inches of fiberglass and wood.
My intention is to use a hole saw. Unfortunately, the centre of the hole is missing. It was drilled out by the previous owner to install ventilation hardware. So I don't have a solid surface into which I can drill the pilot bit.
To make matters worse, the cabin roof is slanted, 10-15%, so I think I need the pilot bit to drill a hole that is close to vertical.
I can think of two solutions. Fasten a piece of hardwood over the existing hole so the pilot bit can bite into it. Or make the best job I can with a jigsaw.
What would you do?
Any help appreciated.
My intention is to use a hole saw. Unfortunately, the centre of the hole is missing. It was drilled out by the previous owner to install ventilation hardware. So I don't have a solid surface into which I can drill the pilot bit.
To make matters worse, the cabin roof is slanted, 10-15%, so I think I need the pilot bit to drill a hole that is close to vertical.
I can think of two solutions. Fasten a piece of hardwood over the existing hole so the pilot bit can bite into it. Or make the best job I can with a jigsaw.
What would you do?
Any help appreciated.