A new Wet Exhaust Outlet

As mentioned in the post about installing the waterlock, I need to replace the old 1 3/4" exhaust hose with a 2" hose.  This means that I need to install a new 2" thru hull in the transom.  The old exhaust outlet was also rather closer to the waterline than ideal (less than 3") so installing a new outlet gives me the opportunity to move it further above the waterline.

The old exhaust outlet is the larger thru hull on the left in the image below:

 

 

On the inside the old thru hull was held on by the standard nut and had an integral 85 degree elbow with a hose barb. 

My first task was to remove the old exhaust thru hull.  It had been bedded with some sort of highly adhesive rubberized compound and the lower part of the nut had been encased in it: the nut was impossible to remove! Brute force was the order of the day: I used an angle grinder to cut eight radial slits around the circumference of the outer part of the old thru hull right down to the wood; I was then able to use a hammer to break off the entire outer ring in segments.  With the outer ring gone I was then able to use a rod inserted into the elbow to wrench the inner part of the thru hull out from the inside:

I then epoxied a plug into the hole and held in in place with a couple of strips of plywood until the epoxy cured:

 

 

The final result once the epoxy cured and before fairing and painting:

The hole for the new thru hull has already been cut in the above image.  It is about 6" above the waterline and hopefully this will provide more protection from flooding as a result of following seas.  I installed a new Groco bronze thru hull and bedded it with SikFlex 291 LOT:

 

I attached the exhaust hose to the thru hull with the required two hose clamps and added a loop as high as possible under the deck to give further flooding protection:

 And finally here is the exhaust hose attached to the waterlock:

 Now I just need to connect it to the engine once that is installed!