Get some hole saws of the appropriate size. For instance, you can't beat the
price here:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=36222
They aren't great saws, but you won't be using them very often.
Measure every dimension you can think of. For instance, try to be sure that
the hole saw teeth will go all the way through the bulkhead. Assuming that
the center drill of the hole saw does penetrate the bulkhead, all is not
lost if you have to back out and cut from the other side, but it's usually
not as pretty a hole.
Before starting to dill, use a center punch to dimple the center of the
hole, so that the drill bit doesn't skid around.
Lube the saw liberally with silicon spray before, and while cutting. Don't
let the saw get bogged down, but keep an even pressure on the teeth all the
way around.
The whole (hole) operation is over in about five minutes, but it doesn't
hurt to think it over for half an hour first. There may be some nuance of
the positioning of the instrument that you have not considered.
--Dave Shugarts
C-27 #4866 Cahoots (1981)
SR, A4, Tiller, Dinette
Newtown (Housatonic River), CT
E-mail: [EMAIL PROTECTED]
Website: http://www.BoatDiddly.com
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On 11/19/06 4:51 PM, "John Oppenheimer" <[EMAIL PROTECTED]> wrote:
> How does one cut a 3 1/2 inch instrument hole into a fiberglass bulkhead?
>
> It's a very common process but I've never seen it done.
>
> John
> C27 5956 Cool Change
> Austin, TX
