Exhaust leaking and rotted through

[ndutton]

I made my own for both the boat engine and my spare engine. My hot sections are black iron and I drilled and threaded an angled hole at the chosen location, threaded in a 3/8" NPT pipe nipple (no sealant) and welded the joint. These have been reliable for years, no dissimilar metals issues, provides an economy of parts and compact installation. The spare engine arrangement is pictured.

A comment on replacing the thru-hull valve in the water:
This is risky business. Removing the existing valve opens the thru-hull to full flow so you'll need to block it off from outside the hull for this operation. Of greater concern though is threading on the new seacock imparts a torque on the threaded thru-hull that could loosen and spin the thru-hull compromising its seal with the hull. If that happens you'll be hauling out immediately.

[mary]

Mary,

I have never used a standard "Y" so will leave others to comment on that.

When I re-did my exhaust, I had to have the shop cut some custom lengths of black iron pipe and I asked them to remove the flange and the injection fitting from the old system. They used a welding torch to heat it all up and they had pipe wrenches/vises considerably larger than mine. Took maybe 10 minutes?

I do not think they charged me much for this.

Peter

I put it in a vise, torched it and wrenched it with a pipe wrench. It doesn't want to budge! Thank you for the input, I'll try taking it somewhere.

[mary]

I made my own for both the boat engine and my spare engine. My hot sections are black iron and I drilled and threaded an angled hole at the chosen location, threaded in a 3/8" NPT pipe nipple (no sealant) and welded the joint. These have been reliable for years, no dissimilar metals issues, provides an economy of parts and compact installation. The spare engine arrangement is pictured.

A comment on replacing the thru-hull valve in the water:
This is risky business. Removing the existing valve opens the thru-hull to full flow so you'll need to block it off from outside the hull for this operation. Of greater concern though is threading on the new seacock imparts a torque on the threaded thru-hull that could loosen and spin the thru-hull compromising its seal with the hull. If that happens you'll be hauling out immediately.

A friend will be diving and plugging the through-hull while I swap it out. I'm also concerned about torquing the thing and compromising its seal. I'll let you know how it goes.

Thanks for the photo and description.. I don't have access to a welder, but maybe I can have this made.

[Tim]

I would not remove the valves with the boat in the water. When I tried to remove the bronze valves from the through hulls the through hulls just spun and the valves would not come off. It turns out the "permanent" bond that 5200 makes is not so permanent, it did not take that much torque to break the bond. I was on the hard, so I just cut the through hulls out and replaced everything.

[ndutton]

Agree with Tim. I'd stay with the current set up until the boat is hauled, do it once and do it right.

[mary]

Just an update to this thread..
I bought seacocks to replace the leaking, scary pvc tapered thread valves that someone had installed on the through-hulls.
A diver friend went below and plugged the holes one at a time while I swapped out the pvc for the seacocks.
I was very careful to not disturb the through hull seal and did not have any issues at all.
I wouldn't recommend this to everyone. You may have different results with your current through hull condition and plumbing experience. I've done a lot of plumbing and felt that swapping them out in the water was better than leaving the sketchy PVC on. They will be installed completely when we haul out.