Balsa Wood on the Tomcat 2006+?

[rockfish]

Hello,

I am in the market for a Tomcat 255, and I am trying to decide what the lowest model year I should consider (assuming 2006+). I've searched the forum high and low but I can't seem to find the answer to whether or not the 2006-20xx TC 255 uses balsa wood core instead of fiberglass (or was that just on their cruisers)?

I know that the 2006-20xx models had wood cabinets instead of molded in fiberglass; but I'm not terribly concerned about that. The thing that scares me is this guys experience:

https://www.youtube.com/watch?v=OxuIwrJ-NQo

Also, when I eventually get to the inspection phase is there anything I should look out for and/or how does one go about finding a quality marine surveyor?

Finally, any other advice this amazing community can provide regarding various model years pros and cons would also be appreciated!

[Barry Rietz]

Rockfish: If you are that concerned about core material present in a second hand vessel, and I would be if it were a $100k plus investment, find a surveyor who uses sonography. X-ray would be the only other type of non-destructive method. One other alternative would be to do a "core sample" by drilling through the hull and examining the sample. The core sample could be done in an area where a depth sounder transducer would be installed. This way you accomplish two goals. Since the C-Dory factory changed ownership many times over the years, you can not determine positively by year what type of core material may have been used.

[rockfish]

[thataway]

There is no guarantee that a boat may not have core issues. I know of two almost new (one was on delivery and the other been used about 6 months) very high end sport fishers, which had foam core delimitation--and the end of the boat. Both losses in the millions, and litigation.

The risk of core problems increase when the boat has been exposed to multiple freeze thaw cycles. I encourage to have all core penetrations, sealed with epoxy, with the undercutting technique.

Generally there have not been many hull core issues. But they do exist, and I am probably aware of more of these than most. It never has dissuaded me from buying anotherwise good boat. Foam cores do not become rotten, but if there is laminate penetration, not properly sealed, there will be water intrusion, and delamination of the foam core from the glass.

Balsa is an excellent core material--not many other materials have the shear and compressive strength. I have sailed 10'x of thousands of miles in balsa cored boats--way offshore, and never worried about it.

Do check for regular water intrusion. If it appears in places it does not belong, then be suspicious. There is probably something wrong. Do moisture tests on a dry floor (easy to do on the hull inside the cabin in both the 22's and 25's. Cockpit in pre 2006/7 22'. Look for penetrations into the core--especially the earlier 22's with screws into core, rather than glassed on strips in later models.

If you can get safely under a dry boat, without bottom paint, and do moisture readings and percussion this will give you a good idea.

The Tom Cats are a different story.. It is fairly hard to access the bottom of the hulls, and much of the bottoms are under tankage fuel and water. The C Dory 25 iinner hull under the cockpit has a fuel tank over it. If the tank is intact, and properly secured there should not be any issues. But there can be damage in a boat which as been abused.

Also the boats in areas where they are left out in the "cold"--subjected to multiple freeze thaw cycles. are at greater risk.

Let me address what my friend Barry mentioned. There is no commercially available ultrasonic technique which will give all of the answers for delaminate and wet cores. The ultrasonic waves only are conducted thru solid media. When there is an air gap, then that is the end of the ultrasonic diagnostic test. You can infer a wet core--if there the bottom measures more than the outer or inner glass layer
s. The sort version; one of my close friends owned NTD of Hunting Beach CA--and designed most of the ultrasonic instrumentation still used by NASA, the Military and civil aviation. He and I had 25 boats to do proof testing on of a technique called pitch and catch. He designed a basic instrument which would retail in the $3000 range and we proofed it on many hulls. The normal model of this type of instrument is in the $16,000 range on up. We took the concept to the various Marine surveyors society and individuals, plus boat builders. Some high end boat builders were interested and would buy. Marine surveyors said "No". They would not pay $3000 to come into the 22 century or take the time to learn how to use the instrument which in the long run would save alot of time. So marine survey remains in the dark ages. Infrared photography can be of some help in looking for moist core, but the definitive test is sample boring--and the seller is not going to allow that!

Xray is not really available or practical. With digital X ray now being the norm, it could become of some value--but I don't know of anyone doing it.

[clayhubler]

rockfish,

I am not an expert in the materials used on the tomcat for varying years. But I can tell you that any cored boat has potential for problems if the core penetrations have not been properly sealed. While foam core may not rot like balsa, it will still soak up water and deteriorate with results that are largely the same. The biggest problem with wet core (whether its balsa or foam) is when it freezes, it will delaminate (meaning it will push the fiberglass skin away from the coring, making a void).

The key is educating yourself, which you are doing, and finding a boat that has been well taken care of. There are common areas that are potential water intrusion spots, and they can be checked. Again, I don't know what areas of the tomcat are cored and what isn't. Others here will probably respond with that info.

I put a lot of work into repairing the coring in my 22 cruiser, but I still think that balsa is one of the best materials used in boatbuilding. I would actually prefer it to foam, because it is stronger. I wouldn't hesitate to buy another c-dory, and hope to move up to a tomcat in the future. You can bet that I will be quite discerning in my examination of any future boat I may purchase. But that would be true no matter what make or model I was looking at.

[T.R. Bauer]

I'd go find a good TC 255, take a good hard look at it and maybe pay somebody to survey it, do a sea trial, and then buy it if it looks good and if what you want. The chances are it's perfectly fine. And if something comes up, which happens with every boat when given enough time and usage, you can fix it or go in a different direction. Yeah....the youtube video....you can find one after another of those outlining how terrible the Honda Accord is as well.....and guess what? It's a great car with a great track record.

[Foggy]

A good article on core materials (balsa, '3 flavors' of foam) and core dysfunction:

https://www.sailmagazine.com/diy/know-core-principles

On eventual cored sandwich hull damage from freeze/thaw cycling, when you find
that perfect boat you want to keep forever, consider living in the (deep) south or
going aluminum.

Aye.

[daninPA]

The OP has received some excellent advice and guidance here so far.

My .02 is simple: relax.

Every complex mechanical toy eventually has “issues.” It’s inevitable for two reasons:
1) wear and tear (entropy)
2) you know more now than the day you brought shiny X home.

Unfortunately the internet has made it possible to “know“ all possible flaws long before experiencing all the joys.

The corollary is: If anxiety of potential post-purchase costs is overwhelming, buy something less expensive to repair and enjoy that.

[thataway]

The Don Casey article Foggy links to mentions honeycomb cores, like Nidacore, I Consider it a good deck (see re-construction of Frequent Sea's cockpit in my album) material. But for hulls, epoxy and balsa.

[Barry Rietz]

Rockfish: If you are still following this thread, here is a link that may lead to finding someone who might help answer your initial question: https://www.ndtyacht.com/

[thataway]

The subject of finding damaged core material is not easy, and there are some very expensive instruments which can show this in a well trained professional's hands.

Here is a manual on fiberglass/composits: resins, cloth, core material. . This is what Naval Architects and engineers use to calculate the materials, strength, and other factors. Balsa stands alone in comparison. This was written in 1997, and I have not searched to see if there is an update. There is not much on some of the glass fiber orientation commonly used, but the information is there.

This is a good article on moisture meters and the conclusion that a $40 Ryobi meter from Home Depot will be as good as an $700 "survey meter".

Here is an article on Ultrasonic testing.. Baisically, the Ultrasonic testing is essential on metal boats. For fiberglass it can be of use, finding old repairs, and delamination due to poor layup, collision or bad repair. It may or may not show anything about any core. (If anyone is interested about why and what, please send a PM, and I will go into detail.) Not used in most fiberglass boat surveys.