I thought I would share some pictures of the new Groco thru-hull fittings that I am putting in Outbound. We are replacing our old Grand Deer and other bronze fittings, which are more than 30 years old at this point. We had one handle shaft break on us recently and we found that one of the cockpit drain valves wouldn't close as it's very difficult to get at to exercise it. We had two through-hulls that were added at some point after the boat was launched for the genset and the AC/Watermaker that were just a valve on top of the thru-hull with a nut configuration instead of a proper flanged seacock. They looked very sketchy and I when we removed them it was more scary the shape they were in.
So to replace them... I was originally going to go with Marelon, but upon doing more research, I found credible information that while the design has improved, they still have issues with the valve shaft shearing. So, i decided to just go with high quality bronze from Groco. Here's what I went with for most of them.
Thru-hull fitting with a heavy bronze flange and a high quality valve with grease fittings and handle that be configured to open either direction with a removable stop. The white piece is a companion backing block from Groco which gets glassed to the hull. It has threaded inserts which the flange bolts to. This allows the valve to be replaced or service without removing it from the hull. The flange also has the proper threads for both the thru-hull fitting and the valve. Many people just thread a valve onto the thru-hull not knowing that one is straight threads and one is tapered. Groco makes the same thing in a unibody valve/flange configuration which I used in a couple of places where height is limited as they are a good inch or more shorter depending on the size.
Lots of shiny new hardware!
I've removed all the old plywood backing blocks and prepped the hull for glassing the new ones in which will happen this afternoon. Since the backing block has threaded inserts, I have to make sure they are oriented correctly to place the valve handle in the right place.
So strange seeing light streaming through the bottom of the boat!
A very good resource that I used:
