Chris Craft Exhaust Alert ( cruisers of the 1960's )

[Paul P]

I'm a wood boat guy from way back, but I'm also an early fiberglass Chris Craft guy too. I presently have a 20' fiberglass Sea Skiff, and a 38' fiberglass Commander, both are 1966 models.

I've recently discovered something about the vintgage CC cruisers that is haunting me, safety related, and I am passing this information on to every boat organization I can. It is the design of the early exhaust collectors on V8 motors that use two rubber exhaust hoses leading to a single welded steel collector, galvanized, which leads to a single exhaust outlet out of the boat. Early fiberglass Commanders (beginning in 1964) and many other wood boats of the era, perhaps Constellations, Sea Skiffs and other Chris Craft boats used this welded steel exhaust collector which was galvanized to add longevity to the assembly.

It now appears that the life span of the design is 35-years in fresh water. I suspect this is not a design that was initiated with the onset of the fiberglass Commander series either, as it could well be used in older wood Chris Craft cruisers, and maybe in other fiberglass Chris Craft cruisers too (like the Catalina).

My 1966 38' Commander, and a friend's 1967 38' Commander both failed in the exact same way, by rusting out the drain down hole intended for winter storage. One is in Tennessee, the other is in Texas. Both boats stay in the water all year long. Boats all over the Great Lakes may or may not have a better rust chance, if they are drained down each year for storage. However, due to what I have seen, it's only a matter of time, and the time is near.

The danger is from carbon monoxide that can also get through the rust holes in small spurts. Monoxide is oderless and it accumulates in the blood stream slowly over time, and the result can be headaches, drowsiness, and even death. The danger aboard a cruiser is much more of an issue, because of the enclosed air space. Therefore if you have a vintage Chris Craft (wood or fiberglass) that was built in the 1960's, please check the type and condition of the collectors.

My 1968 (two years newer) 35' Sea Skiff used a large cast iron megaphone device that should have solved the problem. I think many or all of the boats built after 1968 may have transitioned over to this cast iron collector, but I am sure there are lots of boats still out there (built a few years earlier) with the steel devices .

Owning a vingtage boat as solid as a fiberglass Commander can be very rewarding, but it frightens me to know there is such a danger lurking in so many boats of this era, like a ticking time bomb. Products are available to replace these, and although it may take a little wrestling, the safety payback is well worth the effort and the price. I used a copper collector off another model Chris to fix my problems, and my buddy, Bruce, is either having a stainless steel replica made up, or will use the heat resistant resin/fiberglass product.

If you know a Chris Craft guy with a vintage cruiser, please do him (and his family and guests) a favor and tell him about this potential danger. If he has the steel collectors as shown in the following link, they should be checked (and probably replaced soon). http://www.network54.com/Forum/424840/m ... 1175813057

Sincerely,

Paul

[evansjw44]

You are good to post this issue for us. I have a '35 Skiff with the cast iron collectors and I think most of the CC Cruisers after '63 use it too. But there is a real important thing going on here.

There is a chemical reaction between iron oxide (or rusty steel, FEOx, and in the presence of steam and carborn-monoxide (CO). The CO reduces the FEOx to FE (just plain old iron) and it flakes off the casting reducing its thickness. Eventually it errodes through. The thinner the material, like a rolled steel weldment collector that you have, the sooner the maretial errodes through.

Free CO is bad, even deadly!

My cast collectors weigh a ton and I might not live long enough to have them fail but I keep a watch for leaks. I would expect to see rusty water stains under the collector as it starts to puncture. Assuming you can even see under the clooector.

This is not anything new, actually. The exhaust elbows on the old CC flathead 6's were prone to the same erosion failure. I think most people just called it "burn through" but the reaction is not burning. Cast iron will withstand very hig exhaust temps and not fail. Add the steam from cooling water and we get errosion. Towards the end of the 6 cyinder era you could buy bronze cast elbows that were unaffected by this reation. They just cost a lot. I paid $500 for on in 1972.

[Al Benton]

It's always good practice to inspect the engine and generator exhaust systems regularly as some states require auto owners to do. We're more or less on our own to do it on our boats.

I have a battery powered CO detector in the cabin of my cruiser. They're not exactly attractive and there's just not a good place to mount the thing out of harm's way or out of sight. Mine is mounted on the bulkhead, between the engine and cabin, is in the way and is plain ugly but it's there.

Al

[evansjw44]

I discovered recently the Kohler has a recall on some of their generator exhaust "injector" adaptors. That would be the part that bolts onto the exhaust manifold and dumps the cooling water in. They have this errosion problem going on. I don;t have one of theirs but they will offer a free one if you have theirs. I assume that applies to the 4 cylinder models. Check their website.