With the paint work above the rub rail done, I’ve been working on the exhaust system. Late ’60s Chris Craft Roamer Riviera 46s like mine have metal tubes for exhaust that’s welded in from the engine room bulkhead out through the transom. They all rot out eventually. Mine had pretty severe pitting and I know of one boat that nearly sank when it’s steel exhaust pipes rotted through. Granted, these boats are more than 40 years old, so maybe it’s not surprising that the exhaust would need to be replaced. But since we seriously got into this refit when the paperwork SNAFU was resolved in 2012, I’ve been thinking a lot about the exhaust and how it might be done better.
Initially, when I repowered with the wrong engines back in 2008, I made caps for each end of the original exhaust pipes and had 15 feet of 3.5″ schedule 80 6061 aluminum pipe welded inside. Since I decided in 2012 to install Cummins 6CTAs instead as my propulsion choice, the brand new exhaust that I put in back in 2008 had to come out. I decided to get rid of the pipe out the transom entirely and route the exhaust out the sides of the engine room instead.
On the up-side, fiberglass exhaust should last a lot longer than aluminum pipes, especially with the corrosive nature of diesel exhaust. On the down-side, it’s fiberglass. I finally got over the itchy-scratchies from fiberglassing the cabin top and making the the aft enclosure window frames, I’m not looking forward to working with ‘glass again.
It’s challenging lining everything up for the cut. Just when I thought I had it, I’d look at the top of the 45* Centek elbow and see that it was pointed in the wrong direction. That stubby piece of the 3.5 inch exhaust pipe sticking out into the space didn’t help either.
The great thing about aluminum is that you can cut it with carbide woodworking tools. My beater Skill saw with an old carbide blade made quick work of removing most of the old exhaust pipe. I’ll leave the stub as a chase to go through the bulkhead.
I had to go outside the boat to finish the cuts at the top and the bottom.
The blue tape is like thick shrink tape and resin doesn’t stick to it.
Since this was the first time I’d done this sort of thing, I spent a lot of time thinking through each move before doing it. So what should have taken a few hours took a whole day. No worries…now that I know how to do it, the other side should be much quicker.