Under double sink

[wizard]

Ok fellow CDer's This has me stumped can someone help me out? I have a CD31 and under the double sink obviously is a thru-hull to drain it, however over the thru-hull and it ight be a part of it not sure is some kind of bronze dome. Now I have located the shut off valves for the 3 water tanks, that's not a problem. Does anyone have any idea what this dome thing is about?

[Kevin Kaldenbach]

Is it a cooler for the refer freon?

[wizard]

Well, what I thought was a dome (in the dim light) turns out to be a block spacer mounted under the thru-hull. Under the sink floor, there is about an inch to the hull. They cut out an large circular hole to accept the thru-hull from the floor of the cabinet. In order to get clearance they mounted a block to raise up the thru-hull, so mystery solved. Thanks Kevin for the thought though. Randy

[Kevin Kaldenbach]

Good to see you finaly got your CD31

[wizard]

Thank you, yes I did, found it in Melbourne fl. 1983. It has been out of the water since May 1 and I still have about a month's worth of work to do. It has gone under a major refit, complete engine out and pretty much new everything. I know now how they are built. Not that I wanted to do that extensive of refit, but it needed it, so...and once you start, the domino effect takes over. The hull and deck are being painted this week. Do you have the same spacer under your sinf on that thru-hull? it looks as though it might be mahogony, not sure will be taking out the thru-hull as it is frozen open, probably hasn't been serviced in quite a while. best regards, Randy

[Jeff and Sarah]

Are you sure it's actually a spacer and not a backing block? All of your thru hulls should have a wooden (or fiberglass) block between the flange and the hull. If any do not, now seems like a good time to add one as it sounds like you are already in the middle of a refit.

[wizard]

yes, I called it a spacer, but it is a backing block, looks like it was glued to the hull and then the seacock is on top of that. probably glued with 5200 or something of the like. Is yours wood or some other material?

[Jeff and Sarah]

Yes, mine are wood. Most are mahogany though I have 1 or 2 that are teak. I'm not sure what adhesive was originally used but it stayed somewhat tacky for 30 years. I replaced the backing block for the sink thru hull last year and used teak with 4200. I never use 5200 for anything, but 4200 worked well. I replaced the block because it was showing some rot and subsequently was allowing the through hull to leak a little. It annoyed me to no end so the first time I had a chance I fixed it. CDSOA member Mainesail has a great tutorial on his website about using fiberglass backers.