I'm looking to install a new depth sounder in my 1982 CD30. The hole is presently 1-5/8 inch wide and the new transducer is 2 inches. What would be the best way to enlarge the hole without chipping the glass? Since it's most likely drilling, what bit would be best? Any other options? Thanks.
Regards,
Don
donald.metznik@mail.trincoll.edu
Depth sounder
Moderator: Jim Walsh
-
Duncan Maio
Re: Depth sounder
Don:
You will need the right size hole saw - probably at least 2 1/8" if the transducer is really 2".
Cut a 6" or so square of plywood (or hardwood or even aluminum, if you want real accuracy or are doing multiple holes) and drill a hole in the center using the pilot bit in the hole saw. If there is a wood backing block at the existing hole, screw the plywood to the backing block with the pilot hole in the center.
From the outside of the boat, use the hole saw to drill part way through the hull; the pilot hole in the plywood will if you can get inside, drill the rest from the inside.
If you intend to add a backing block, just drill the appropriate size pilot hole in the backing block, and epoxy it in place before you drill the big hole.
Depending on access and whether you have a helper, it may be simpler to skip the pilot hole step, and just use the filler block to give the pilot bit something to bite into. In any case, you may need to get a longer bit for the pilot bit, as the ones that come with hole saws generally only extend up to 1/2" out from the big cutter.
Good Luck.
Duncan Maio
s/v Remedy
CD27 #37
dmaio@meganet.net
You will need the right size hole saw - probably at least 2 1/8" if the transducer is really 2".
Cut a 6" or so square of plywood (or hardwood or even aluminum, if you want real accuracy or are doing multiple holes) and drill a hole in the center using the pilot bit in the hole saw. If there is a wood backing block at the existing hole, screw the plywood to the backing block with the pilot hole in the center.
From the outside of the boat, use the hole saw to drill part way through the hull; the pilot hole in the plywood will if you can get inside, drill the rest from the inside.
If you intend to add a backing block, just drill the appropriate size pilot hole in the backing block, and epoxy it in place before you drill the big hole.
Depending on access and whether you have a helper, it may be simpler to skip the pilot hole step, and just use the filler block to give the pilot bit something to bite into. In any case, you may need to get a longer bit for the pilot bit, as the ones that come with hole saws generally only extend up to 1/2" out from the big cutter.
Good Luck.
Duncan Maio
s/v Remedy
CD27 #37
dmaio@meganet.net
-
D. Stump, Hanalei
Re: Drilling the hole...
Don,
I haven't done this, but given the problem, here is what I would do:
Buy a hole saw that is 1 5/8". Find a piece of wood the same thickness of the hull where the hole is and cut out a 1 5/8" plug. Take the plug to the boat and with a little sawdust to make everything tight, mix up an epoxy/sawdust paste and use that to install the wooden plug into the hole in the boat. Once the epoxy cures, you have a center pilot hole to guide the cutters on a 2" hole saw that you purchased for the new thru hull. Cut the hole a little from the outside and a little from the inside and you won't chip the surface either inside or outside. Finish cutting the hole and install the thru hull fitting. You're done!
The wooden plug is only there temporairly, so it doesn't have to be anything special. It is only the guide for the new thru hull hole saw. I would think this would work and be relatively easy to accomplish. Let me know how ya make out....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
I haven't done this, but given the problem, here is what I would do:
Buy a hole saw that is 1 5/8". Find a piece of wood the same thickness of the hull where the hole is and cut out a 1 5/8" plug. Take the plug to the boat and with a little sawdust to make everything tight, mix up an epoxy/sawdust paste and use that to install the wooden plug into the hole in the boat. Once the epoxy cures, you have a center pilot hole to guide the cutters on a 2" hole saw that you purchased for the new thru hull. Cut the hole a little from the outside and a little from the inside and you won't chip the surface either inside or outside. Finish cutting the hole and install the thru hull fitting. You're done!
The wooden plug is only there temporairly, so it doesn't have to be anything special. It is only the guide for the new thru hull hole saw. I would think this would work and be relatively easy to accomplish. Let me know how ya make out....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
-
Neil Gordon
Re: Depth sounder
>>I'm looking to install a new depth sounder in my 1982 CD30. The hole is presently 1-5/8 inch wide and the new transducer is 2 inches.<<
I was doing the same thing a few years ago, until I found that the old transducer worked just fine with a new meter. If you haven't tried that yet, you might save a fair amount of work.
Regards, Neil
s/v LIQUIDITY
Cape Dory 28 #167
neil@nrgordon.com
I was doing the same thing a few years ago, until I found that the old transducer worked just fine with a new meter. If you haven't tried that yet, you might save a fair amount of work.
Regards, Neil
s/v LIQUIDITY
Cape Dory 28 #167
neil@nrgordon.com
-
Don Metznik
Re: Depth sounder--Thanks to all
Thanks to everyone for the advice. I think that I'll go with filling the hole with a plug and then drilling it out with a 2-1/8 saw drill. I greatly appreciate everyones advice. Thanks again, Don.
donald.metznik@mail.trincoll.edu
donald.metznik@mail.trincoll.edu