Hello All,
I tore into my '83 E38 in preparation for spring yesterday. I didn't care for the looks of several seacocks so I pulled them all today. Here is what I found:
7 total seacocks, ball valves/thru-hulls really, not the flanged seacock. 4 of them under the starboard/aft section of the galley counter in that almost impossible to reach cabinet next to the engine. The other three were in the head, almost as difficult to get at. 5 of the thru-hulls were PLASTIC topped with Marelon ball valves. The last 2 were bronze, with bronze Apollo/Conbraco valves. All thru-hulls have a tapered seat and are completely flush with the hull.
Here is the scary parts:
The large 1 1/2" valve that is the galley sink drain was only threaded onto the bronze thru-hull nipple TWO AND A HALF TURNS! It was barely hand tight. The 1 1/2" Marelon valve behind it that is connected to two of the cockpit drains was completely frozen open. The 1 1/2" hose that connects to the drains is dry-rotted/cracked on close inspection. The 3/4" PLASTIC thru-hull with Marelon valve that feeds the raw water pump had a 1 foot tall bronze extension sticking off the top. Perfect for putting plenty of torque on that plastic thru-hulls so it will snap off.....
Seeing that backing blocks are in excellent shape and the location of all the valves in such that it would be impossible to kick them or place much stress on them I am planning on replacing with ball valves again instead of the flanged seacocks. The Apollo/Conbraco valves are in decent shape so I may reuse them. The Marelon valves are decent too, but I don't really care for plastic below the waterline. At least the thru-hulls will be all bronze this time.
I am pretty sure the "not enough threads" issue with the sink drain valve and thru-hull is a NPS thread to NPT thread conflict. I think Groco makes a bronze thru-hull with the correct threads. I would prefer to replace the Marelon valve with Groco bronze. The plan is to replace what needs it, reuse what is good and reseat it all using the backing blocks that are there.
I have looked at the local marine stores and all the thru-hulls I find are designed to be surface mounted, that is they don't have a tapered face to allow them to sit flush like the current units do. Anyone know of a source for the tapered seat thru-hulls?
Any input at all on this stuff would be great. Its my first time around with all of it. Thanks, RT
I tore into my '83 E38 in preparation for spring yesterday. I didn't care for the looks of several seacocks so I pulled them all today. Here is what I found:
7 total seacocks, ball valves/thru-hulls really, not the flanged seacock. 4 of them under the starboard/aft section of the galley counter in that almost impossible to reach cabinet next to the engine. The other three were in the head, almost as difficult to get at. 5 of the thru-hulls were PLASTIC topped with Marelon ball valves. The last 2 were bronze, with bronze Apollo/Conbraco valves. All thru-hulls have a tapered seat and are completely flush with the hull.
Here is the scary parts:
The large 1 1/2" valve that is the galley sink drain was only threaded onto the bronze thru-hull nipple TWO AND A HALF TURNS! It was barely hand tight. The 1 1/2" Marelon valve behind it that is connected to two of the cockpit drains was completely frozen open. The 1 1/2" hose that connects to the drains is dry-rotted/cracked on close inspection. The 3/4" PLASTIC thru-hull with Marelon valve that feeds the raw water pump had a 1 foot tall bronze extension sticking off the top. Perfect for putting plenty of torque on that plastic thru-hulls so it will snap off.....
Seeing that backing blocks are in excellent shape and the location of all the valves in such that it would be impossible to kick them or place much stress on them I am planning on replacing with ball valves again instead of the flanged seacocks. The Apollo/Conbraco valves are in decent shape so I may reuse them. The Marelon valves are decent too, but I don't really care for plastic below the waterline. At least the thru-hulls will be all bronze this time.
I am pretty sure the "not enough threads" issue with the sink drain valve and thru-hull is a NPS thread to NPT thread conflict. I think Groco makes a bronze thru-hull with the correct threads. I would prefer to replace the Marelon valve with Groco bronze. The plan is to replace what needs it, reuse what is good and reseat it all using the backing blocks that are there.
I have looked at the local marine stores and all the thru-hulls I find are designed to be surface mounted, that is they don't have a tapered face to allow them to sit flush like the current units do. Anyone know of a source for the tapered seat thru-hulls?
Any input at all on this stuff would be great. Its my first time around with all of it. Thanks, RT