Hull cross section at sump?

[cbadmin]

From: Chuck S (Original Message) Sent: 7/11/2003 3:44 PM
Is the hull cored at the sump on a 16 cruiser? There's a significant depression there and enough room to install a transducer for a depth sounder inside the hull shooting thru it. This method works fine on a solid hull, but not thru a cored version.

-- Chuck

From: Mike Sent: 7/11/2003 8:44 PM
Chuck -

According to the C-Dory web site on the 16' construction details page, the hull thickness is 1 7/8". It is almost certainly cored.

Mike

From: Chuck S Sent: 7/12/2003 6:38 AM
I'm certain the hull is generally cored, however at the sump there's a good inch depression which lead to the question regarding this small specific area

I'd like to avoid both transom mounted and thru hulls if at all possible. I've done plenty of thru hulls on cored hulls, so I have the technique down but shooting thru the hull is much cleaner. The sump area is away from the fuel tanks and one of the few places on this little boat for a thru or inside the hull mount.

I bought this boat to get into shallow places -- just want to know how shallow I'm going!

-- Chuck

From: Mike Sent: 7/12/2003 1:19 PM
Im still betting there's some wood beneath the depression. The sump on my 22' is about 3/4" deep, and there is wood under it. You could drill a small hole to find out for sure. The bit cuts real easy when it hits balsa. Shoot, what's another hole in the boat? You can always use epoxy to make it go away.

I know what you mean about the transom mounts. I just stuck a new transducer on the back of mine, and there it is sticking out there ready to get knocked hatwire.

Mike

From: Chuck S Sent: 7/12/2003 3:45 PM
Mike --

Thanks, if I decide to test drill I'll probably mount a thru hull if I can find my large chamfer bit.

-- Chuck

From: riverrat Sent: 7/14/2003 1:17 PM
As far as the question of whether the drain plug sump is cored or not, just set the transom mount transducer in the sump, with a good glop of vaseline, or Crisco under it (no air bubbles) & try her out in the water???

The x-ducer is exactly the same construction as the glue-in (puck) kind you get for in-hull mounting. The goop acts the same as the epoxy or 100% silicone caulk you would mount it in permanently. You can also do the test by putting a little water in the sump - it works just as well as air-free grease. You would have to have someone or something hold it down though.

Regards

Riverrat on "Chinook"

From: Chuck S Sent: 7/15/2003 7:34 AM
Thanks, the factory just confirmed that the hull under the sump is indeed cored, so a thru hull is needed, or the area has to be opened up and filled with epoxy and microballons. Thru hull seems easier.

Not I gotta look at them again, the last couple I put in (sailboats) had chamfered holes, so I'll have to find the bit I had made.

-- Chuck