Exhaust Fitting

During our haulout in July, I discovered the exhaust thruhull fitting on our Krogen 42 was cracked.* We made adequate (but temperary) repairs to it.* I am now on a quest for a good quality exhaust fitting.* Recently, I saw what looked to be a stainless steel (it may have been chrome/brass) exhaust fitting with a hinged metal flap over the opening.* I was unable to ask the owners about it.* So far my quest has been a dismal failure.* Can anyone point me in the right direction?

Sounds like a custom job to me. Go to your local (if you have one) Marine Exhaust Specialist. Describe what you want, and the dimensions needed. Google "National Marine Exhaust" in Marysville, Washington. They could probably fabricate it and mail it to you. I used them years ago to fabricate a replacement exhaust elbow, and the product was great.
Carey

A flap is not anywhere near enough protection to keep the exhaust from being flooded in a following sea.

A loop , above the hight the transome normally immerses with BIG following seas is the only solution.

A check valve in the exhaust line is an equally unsatisfactory solution.

FF

Custom is what you will have to do. Another alternative is fiberglass tube. No bonding no corrosion.

Another alternative is fiberglass tube. No bonding no corrosion.

But you will need a cooling water alarm , should the water flow be cut off or obstructed , even FR Grp resin burns.

FF

"Can anyone point me in the right direction?"

http://www.cpperformance.com/products/Exhaust/flappers.htm

Is the fitting in solid*FRP or laminate? In either case the surrounding material will likley require a proper redo

Is the fitting in solid FRP or laminate?

ALL GRP or FRP is laminated , there are no fiberglass solid castings used on boats.

The resin is very week , and gets its strength from the layers of glass.

The unit on the link is SS with sometype of rubber to close it .


-- Edited by FF at 05:29, 2008-09-19

FF - Thank* you for your diligence in reminding me that I am a lesser light..
*
Let me rephrase: Is your through hull fitting in "solid" FRP or core (or as some experts refer to it as "laminate"). Some Krogens have cored hulls. This requires*that any through hull fitting must be properly rebedded to eliminate any possibolity of migration of water into the core.

"This requires that any through hull fitting must be properly rebedded to eliminate any possibility of migration of water into the core."

NOPE!

The bedding compound is NOT what saves a hull from water ingress into the laminate.

Proper construction ,for a proper instalation is required before the piece is fitted.

The hulls penetrations , solid GRP or cored MUST be sealed , best with epoxy and glass , so the bedding compound keeps the water from leaking inside the boat , but the BOAT keeps the water from inside the hull laminates.

This fact is usually overlooked ( by initial builders or later boat modifiers) and as the extra steps take days to complete , due to the hardening times.

Thru hulls and seacocks are frequently better done , than the decks and cabin sides that really eat time.

Time is MONEY in a boat assembly shop.

FF

"Properly rebedded" should be detailed, much beyond FF's short discourse.*The better explanation I have seen was in PMM about 2 years ago and covered those "holes" both above and below the waterline. A good yard (FF ran one in the last century) can do this work for you, which on an exhaust through hull I would recommend.*But back to the question, is your exhaust through hull in core*or solid FRP?