How thick is the deck?

[HeaveToo]

I am going to put a radio in my Compac 23 cabin.  I bought a mount for the radio and I am thinking that it would be nice to mount it in the area in the cabin under the side deck.  How thick is the deck and what size stainless steel screws should I use to attach this to this area without going through the entire deck?

Here is the mount:  http://www.westmarine.com/buy/poly-planar--radio-mount-universal--9389446

It is hard to describe the area I am talking about.  It wouldn't call it the cabin roof but above the shelf that runs down the side of the main cabin area.

[brackish]

I think I understand where you want to put it and I'm not sure how thick it is there.  I know that on my foredeck, at the same level some parts of the deck are cored with a honeycomb poly material for strength and that is between two relatively thin layers of GRP.  The side deck may or may not be the same, I've never penetrated it.  That core material has no screw holding power.

At any rate I wouldn't do it like that.  I would be afraid that even if I didn't come all the way through the side deck glass layer I might set up a stress point that would eventually crack and cause a leak.  If you want to hang it from the side deck, I think I would epoxy a wooden plate up there, then screw the mount into that.  Or use some of those studs that have perforated flanges that are designed to be epoxied to a surface.  Alternatively, turn the mount over and screw it directly to the shelf if the radio can be mounted that way.

You could give your serial number to Hutchin's, they would have the glass schedule used for your specific boat and know the thickness.  The schedule may have changed over time. 

[HeaveToo]

Brackish....that makes a lot of sense.  Maybe it is best to mount it on top of the shelf then.  I was thinking of a way to not interfere with the length of the shelf for storage.  I also didn't consider the suggestion that you put forth about a stress point.

I am not wanting to cut into any wood on the boat.  Placing it on top of the shelf wouldn't interfere that much with the space there as it isn't very tall.  The wire run from the stereo would be hidden by running it into that storage area.  That may be the winning ticket!

That area has a liner, kind of a carpet-like material.  Epoxy would probably be more work than it is worth also.