Revival #2 - just doing this job. Have removed the old stainless cockpit drain standpipes with welded on skin fittings today. They've been leaking since last summer, we then patched them up with underwater epoxy (freediving) and finally got around to doing our "spring" haulout.
First I gave them a good tug, as I wanted to know if they were teetering on the edge of snapping off and the long levers inside the engine room have always worried me a bit. Luckily, they hardly moved and nothing snapped off, so that part wasn't too worrying.
They then came out reasonably well. I put some release spray on the nuts and washer and then drove the huge (75mm across flats) nuts lose with a hammer and screwdriver, as they already both had chisel notches in the right spots. Once they started turning, I got a clamp on (didn't have a big enough adjustable spanner and it's night impossible to get to a hardware store from the Aktio peninsula - shuttlebusses are corona-cancelled). Some cussing for lubricant and the nuts came off eventually. Then disconnected the hose at the top and pushed the fittings out the bottom. Had to stab at the sealant a bit to losen them.
Out they both came. Both had significant crevice corrosion on the outside AND inside of the skin fitting (on portside, the original sealant had partially failed) and some very fine pitting, which was the source of the leak - water was seeping through the stainless at the welds, and there's several welds, one on the skin fitting flange and another at the top end where the threaded section joins the standpipe.
There were also backing plates, which I assumed were made of fibreglass (they were covered in sealant on the inside, so couldn't tell). To my surprise they turned out to be made of plywood. One came out intact and dry, the other had gotten wet from pitted stainless leaking, delaminated and fell to pieces when I removed it.
On the upside, the hole is slightly larger but not too large for the 2" Tru-Design seacocks, and there is enough room for the new skin fitting in the recess. On the downside, the inside and outside of the hull were not quite parallel, something the ample sealant previously compensated.
So I'm doing some grinding and will install the new skin fittings with thickened epoxy tomorrow, at a slight angle and flush to the hull so they cannot be harmed by lifting slings. Then fair the outside somewhat before applying some more Coppercoat. Wish us luck!
Oh! And the 2" Tru-Design ball valve with load bearing collar fits in the corners of the engine room, but only just. Had to remove the handle to dry-fit and also cut off a little bit of noise insulation foam, but that was easy.
