Check your wet exhaust pipes thoroughly

[Cap Morgan]

I thought I’d share a recent experience which may be helpful to those purchasing an old boat with an inboard engine or who may already have one. Last Tuesday I finally got my 1980 Cal 39 back into the water after a month and a half in a boatyard doing some bottom work as well as other tasks. Once the lift lowered me into the water I started the engine and then began backing away. I had opened my engine hatches just to check for odd sounds and smoke which turned out to be a good thing. I expected there to be some smoke with solvents burning off etc. Unfortunately, what started out as light smoke which should have burned off actually got a little worse. Fortunately, I wasn’t going far but over to the end of a dock where I’d spend the next 24 hours observing the boat for any issues prior to heading off to Miami.

As soon as I tied up to the dock and looked underneath the engine hatch in the cockpit it was readily apparent that one of the elbows on the exhaust riser had completely sheered off the pipe running vertically up to connect with the riser where it crosses to the other side of the boat. I immediately shut her down as sea water was spraying all over my engine compartment! So the smoke I was seeing had really been a mix of exhaust and steam. First off although extremely disappointed that this would throw a wrench into my plans I was also very thankful that it happened right there at the dock. Imagine the alternative!

What really struck me about this experience is that this very large and imposing component was so badly rusted and yet missed by all. My Surveyor missed the flaw, a Diesel Mechanic that I hired to do an inspection missed it and I had no clue of the bad shape that my exhaust was in (see photos). So you may be asking, how could this have been missed? The answer is quite simple. The exhaust, which was made of regular iron pipe ( as I suspect many are) is wrapped with several layers of insulation it’s entire length. As a result there is no telltale evidence of what really lies below. My exhaust was essentially a standing pile of rust. Please check your exhaust by unraveling some of that insulation!

I hired a mechanic to build me a new one and because I’m stuck at a pricey Marina he’s building the new one out of the same material because he balked at using the 316L stainless that I’d like. So as not to cause further undue delay, I’ll just have him build it his way then once I’m home I’ll dismantle. And use to customize a new 316L stainless exhaust.

Hope this is of help to some.

Cheers!

[Smooth Move]

Yes I’ve had this happen. Went in to boat yard for engine mount replacements . Boat never sea trialed and sent me out with a cracked exhaust riser . I thought I was on fire and fortunately made back to dock very nervous and pissed . Like you the problem declared itself pretty fast. Bad clean up in cabin with diesel smoke damage.

[Bill O]

Yes, cast iron elbows need to be inspected and replaced periodically as they will rust out.

What motor do you have in your Cal?

Before you go through the effort to make a new one, would check with HDI to see if they have one in stock for your motor. Their SS cast elbows are very well done. The HDI elbows are typically less expensive and will outlast the elbows made of 316L tubing that most others sell.


btw, no photos were attached in your original post.

[Cap Morgan]

Originally Posted by Bill O

Yes, cast iron elbows need to be inspected and replaced periodically as they will rust out.

What motor do you have in your Cal?

Before you go through the effort to make a new one, would check with HDI to see if they have one in stock for your motor. Their SS cast elbows are very well done. The HDI elbows are typically less expensive and will outlast the elbows made of 316L tubing that most others sell.


btw, no photos were attached in your original post.

Bill, The boat has a Perkins 4-108 with 1135 hrs or so. Also, I caught the error with the original post and added the photos. Please let me know if you still can’t see them.
I’ll definitely try that cast elbow when I rebuild my exhaust.
Thanks for the response!

[Jono as 2234]

Checking the elbow is all very well, but the corrosion is on the inside

[Bill O]

Sorry, still do not see any photos. May need to attach them to a new thread response for them to show up.