Copper exhaust repair. Epoxy?

[Sdtimbercruzer]

Hi there. Was wondering if any one had experience with repairing copper exhaust with epoxy? Have a 1970s timber cruiser and looking for a medium term solution to a corroding exhaust. If anyone has experience they would like to share, would really like to know of any recommended products. An example I found was "just for copper" but is rated to 260 degrees Celsius. Not sure of the operating temp of raw water cooled pipe so not sure this is right product. Thanks in advance Stephen

[Bill O]

Stephen,
Does your cruiser have a gas or diesel motor?

If diesel, my understanding was the burnt diesel created sulfuric acid and copper wasn't the best for a diesel exhaust system.

[1affiah]

A roll of automotive fiberglass exhaust tape should be part of every boater's toolkit. Using a stainless worm gear clamp along with a piece of steel can and the tape for a gasket could allow a temporary patch to be made on most any exhaust system, gas or diesel.

[Cheechako]

It would help to have some pics of the corrosion, how bad it is and how aggressive.
wet exhaust ? Fiberglass tape is probably the best answer for that.

[Sdtimbercruzer]

Thanks for the reply. Yes wet exhaust. Will take some photos on the weekend and share.

[Sdtimbercruzer]

Originally Posted by Bill O

Stephen,
Does your cruiser have a gas or diesel motor?

If diesel, my understanding was the burnt diesel created sulfuric acid and copper wasn't the best for a diesel exhaust system.

Thanks for reply Bill. Yes she's a perkins diesel 4.236M to be precise.

[sailormed]

I have a Yanmar 3JH4E (non turbo, 3 cyl) installed in our boat. The exhaust temp measured right downstream of the water injection elbow is maximum 48°C at max 3300 RPM. So epoxy is possible temperature wise.

[Bill O]

Originally Posted by Sdtimbercruzer

Thanks for reply Bill. Yes she's a perkins diesel 4.236M to be precise.

While fiberglass tape is probably a good temporary repair item to have on board, would change out the copper to a rubber exhaust hose for the long term/near forever fix.

What diameter is the copper? The standard mixing elbow off the 4.236 is a 3" exhaust port. Anything less dia. in the exhaust system will create back pressure and reduce the performance of the motor.

[Cheechako]

Originally Posted by Bill O

While fiberglass tape is probably a good temporary repair item to have on board, would change out the copper to a rubber exhaust hose for the long term/near forever fix.

What diameter is the copper? The standard mixing elbow off the 4.236 is a 3" exhaust port. Anything less dia. in the exhaust system will create back pressure and reduce the performance of the motor.

Good point, being a wet exhaust it makes sense to just change out to rubber exhaust hose.

[Boatyarddog]

Originally Posted by Sdtimbercruzer

Hi there. Was wondering if any one had experience with repairing copper exhaust with epoxy? Have a 1970s timber cruiser and looking for a medium term solution to a corroding exhaust. If anyone has experience they would like to share, would really like to know of any recommended products. An example I found was "just for copper" but is rated to 260 degrees Celsius. Not sure of the operating temp of raw water cooled pipe so not sure this is right product. Thanks in advance Stephen

Out drive exaust boot some hi temp silicone sealer and clamps.
Like this, of appropriate size.
Temporary fix.

https://www.amazon.com/GHmarine-Exha...a-758552437400
Boatyarddog

[Rumrace]

Silicone cut that copper out. It’s a plumbing pipe. The copper corrodes for two reasons it’s the weakest metal and the acid in exhaust. Part of our fall storage ritual is to change oil to keep the acid out of the engine during the winter and antifreeze in particular the exhaust heater exchange header as well as block.
There was a previous thread about a Hinckley Exhaust to having heat coating on one spot. This apparently allows the copper to overheat. I believe most manufactures are changing as the drive lines are availed.

[Rumrace]

Oh and there is an Epoxy bandage repair. It’s temp easy and will break again.
Any automotive store. You want an catalytic bandage.

[Flatswing]

Just replace with rubber exhaust hose- really not worth the risk of a major water/exhaust leak. FRP works well for connectors. Btw My JD 6068 TFM50 wet exhaust temps are usually 103F in 80 deg Southern waters.

[DrDelmas]

I have used JB Weld on my Steel exhaust elbow wit great results.
I found this on the web

Epoxy pipe lining is an increasingly attractive option for copper pipe pinhole repair because it both solves and prevents problems. By coating the inside of copper pipe, copper epoxy seals pinholes and blocks the corrosive action of elements in water so that no new pinholes develop.May 23, 2017
https://curaflo.com › copper-epoxy
Copper Epoxy | Lining for Copper Pipes – Coating & Repair – CuraFlo

So I am guessing it would work for you too