Exhaust(ing) Woes

[capngeo]

So, in a fit of energy, I decided to replace all the hoses on my CAL28.... who knew there were so many? Regardless, this thread is about the exhaust. The hose was stiff, there were little beads of rust coming through the outer cover.... It was time.

It is amazing how much of the boat required disassembly. Further amazing is how much junk has been pigeon-holed into every nook and cranny over the last 30 years. I always excused the near-hoarding because for years the boat was a semi-liveaboard (she was my Key West home). The boat is going on a diet when I start to put it all back together.

I digress: the through-hull for the exhaust went through the transom about 6" above the waterline. It lived in a nasty spot in the laz, under the auto-pilot ram, behind the water heater. Much blood was spilled just gaining access. As I got close enough to actually loosen the clamps, I saw a bit of questionable corrosion on the stainless through hull exterior; man, I did NOT want to replace that too! More blood was spilled, and my wife had to help, as all the bolts were jammed up in 5200.

The original equipment was rather poorly made, with the bends being simple angle cuts reversed and welded together. The welds were amaturish; I found that rather odd, as the rest of the CAL has proven to be very well made with great workmanship. The decision was made to replace it entirely. Just to appease my thrifty disdain for frivolous spending, I decided to do a little destructive testing. I clamped the pipe in my vise, put a piece of round stock in the other end and gave it a bit of a tweak. IT SNAPPED CLEAN IN TWO! Crevice corrosion was plainly present at the break. I then submerged the pieces in muriatic acid. That disclosed many more spots corroded through or nearly so.

Obviously, this part was long past its useful life, and had the boat and crew in imminent danger. The lesson learned, albeit distasteful, is regular disassembly and inspection of those out of the way components.

I fabricated the new part out of mandrel-bent 316 stainless tubing. In the process, it was re-designed to make it a lot easier to route the hose, and all the sharp corners eliminated.

[MarkJ]

You've done well.... Lots of hard work too!