Current Factory procedure: Balsa Core Penetrations?

K

Karl

New member
The balsa core of the C-Dory line has been controversial...it is pretty-much agreed-upon that balsa coring can be a positive or a negative...

Best-practice is that when penetrating the balsa core, the balsa will be cut back under the fiberglass skins, and filled with epoxy, so that no balsa will be exposed to water even if the fitting eventually leaks water.

The cheap-assed alternative is to simply leave the balsa core exposed, but seal the fitting (thru-hulls, screws for trim tabs, etc., etc.) and just run a bead of 4200/5200 sealant under the attachment.

Does anyone know which approach the current manufacturers of C-Dory are using?
 
Million dollar boat manufacturers don't do this correctly and I'm sure the current C-Dory process is no different from what you describe. Exposed core with cheap/easy slathering of something like bostic.

With time and motivation we can all fix this poor work fortunately.
 
Too, bad, really, that doing it correctly is not being done.

I personally would jump at a "correct" option as a $500 upgrade, to have it done right by the factory.

I'm begininng to see why the factory hull warranty is so limited.

People fear balsa core, for good reason.
 
Karl":6ikd9ik5 said:
Too, bad, really, that doing it correctly is not being done.

I personally would jump at a "correct" option as a $500 upgrade, to have it done right by the factory.

I'm begininng to see why the factory hull warranty is so limited.

People fear balsa core, for good reason.
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WRONG! Why don't you do a search and find out how many C-Dory owners have initiated a hull warranty claim due to balsa core failure? I bet none. The hull warranty by the factory is for five years. Our boat just turned 6. We've had no problems with the balsa core and certainly do not FEAR balsa core. I'm not sure there are many current C-Dory owners who fear balsa core either. Hey, maybe that should be our next poll. Who fears balsa core?

BTW, love our C-Dory! :thup
 
Karl wrote:
The balsa core of the C-Dory line has been controversial.
Click to expand...

Karl, I am curious as to who finds the balsa core of the C-Dory to be controversial. Do you have a reference?

If you want to know how the factory does things, there is a link to Triton Marine on the front page. You can ask them directly.

The only balsa core problems that I know of are the balsa cores of the transoms on the older C-Dory Classic boats built in the early 1980's. Some of them have had their transoms rebuilt due to water intrusion from poorly sealed motor mount bolts. C-Dory stopped using balsa in the transoms, but I don't know the actual date. The only other core problem was a 22 C-Dory that had a delamination failure of the core and that boat was replaced under warranty by the Reynolds owners of C-Dory. The Reynolds are long since out of the C-Dory business. The current owners, have a long history of building fine boats. Prior to building C-Dorys, they built the Sea Sport line of boats.
 
There are few if any other materials which have the compressive strength of Balsa for core materials. I am not sure that Triton Marine is using Balsa in the core currently--I recollect that they are using a foam.

David Pascoe has a number of articles on Balsa core including this one:
http://www.yachtsurvey.com/cored_hull_bottoms.htm

I can also directly quate Ian Farrier (Designer of the Corsair and F series of Tris) :
Balsa is perfectly fine underwater, provided it is sealed properly when being fitted, when any holes are drilled through for fittings, and it must also be resealed immediately if exterior laminate is damaged in any way.
As to balsa being used in hulls generally, it has been done quite successfully, but it does need special care in both construction and maintenance. For my own boat I would be be happy to use 100% balsa throughout for any trailerable, particularly with epoxy resin, but I would have reservations about using in any non-trailerable boat that was to speed 100% of the time in the water. In that case, foam would be my first choice, followed by stripped plank cedar, then balsa, then ply.

There have been a few core problems with C Dories in the past--but minimal. I can remind that some of the 25's had cockpit deck problems, which I both illustrated and then showed the repair of. The few cases were there was some limited water intrusion from a screw has been a small area and easily repaired. It is amazing that there are very few core problems considered that over 1000 c Dories have been built. Some other boats--like Sea Ray had far greater problems--and recently a new Bertam 55 sport fisher basically fell apart with a core problem.

Yes, thru hulls should definately be sealed. Both for water intrustion and compression of the core material, as a thru hull is screwed tightly (or too tightly) into a cored hull. It is not difficult to correct those issues on a new boat if you want to. Or you can go to glass and epoxy tabs and eliminate the screws entirely.

I have been one of the few folks to have been on a boat which hit a semi submerged shipping container and the boat sustained only minimal damage,due to construction of balsa planks (2 1/2" x 2 1/2") with good glass inside and outside of the core. I believe in balsa cores--but properly taken care of and constructed. The C dories have enough glass on the bottom to be good cored boats--but the holes do need to be cared for.
 
Karl,

Well there you have it.....no balsa = no problem. Why don't you get a new CD 22 and give us a report back on how much you love it?

BTW, I have no worries about balsa in my old 1994 CD 22. Heck, the boat still looks like new almost. But that is thanks to storing it in the shop and out of the weather probably. I hope to get 30 more years out of her.....
 
I'd wait until (if) Scott Boysen or Jeff Lindhout replies. When I was there, I seem to remember a 22 being laid up with balsa. Foam is a good bit heavier and I don't see changes in the specified weight of these boats.
 
As far as I know CDs are built as they always have been with reliable ,proven , strong and light Balsa. When Scott Reynolds acquired the Cape Cruiser molds they switched to composite core and are still built that way . If you spend too much time analyzing and fretting over things that may or may not happen , you will miss alot of the fun boating life has to offer . If you can build boats better ,then do it !
Just my 2 cents .
Marc
 
I too am surprised that there have not been more soft core problems. I temporarily looked elsewhere due to the balsa used in C-Dory and the consensus they were not sealing core penetrations properly. I obviously decided to return!

I have been very diligent to follow the Dr. Bob approved method for ALL core penetrations. I avoid drilling holes like The Plague and when I do I follow the full proper procedure.

With the above being said, there have been few core related problems. C-22's and others had problems with bilge pumps drilled right into the cored floor that caused small soft areas, there were instances of fuel tank straps as I recall that were drilled right into the cored floor that also caused small soft areas, and then there were instances of the brass bow plate that were drilled through the core causing water intrusion. These folks were able to do the correct procedure and fix their various issues. Basically places where standing water may result (i.e. bilge pumps) are a particularly bad idea for improperly sealed core penetrations. Owners of the C-22 could comment with more authority.

There have been very few problems with the core. The testimony of thousands of owners is worth more to me than any brochure discussing superior construction methods. :D Would I prefer something other than balsa? Yes. Did it prevent me from purchasing a vessel with great confidence? No.
 
Worried about balsa core? interesting that the older C-Dory's are worth more now then they were new. I'm sure if they all were filled with dripping wet soggy core they would not fetch the prices they do. I'm not sure how you get a 22' Cruiser bare hull to weight in at 2000 pounds without using balsa. Encapsulated balsa can take a pretty good hit as mentioned before and is so strong these boats are built with out a traditional stringer system. Balsa allows these fine boats to be powered by much smaller engines making them relatively cheap to run and light to trailer around the country. The lighter weight translates to a smaller more fuel efficient tow vehicle. The 23' Venture models weigh in about 1000 pounds more being a little longer and using a foam core. So I don't think you can find boats that hold their value better than a C-Dory or Cape Cruiser :) of any year. Triton Marine did not just fall off the turnip truck and end up in the boat building business. They have a long history of building boats that stand the test of time. Good luck finding what you are looking for.
D.D.
 
Good question and an age old one. I guess the simplest way to answer it is that no matter what core is used, if it is not laid up properly or cut into properly it will not last. We use balsa core that is vacuum bagged into place on all Cdories, and foam core that is vacuumed bagged into place on all the Venture models.

When doing a thru-hull for a seacock the proper procedure which we utilize here at the factory, is to back cutout 3 times the diameter of the thru-hull and then fill with thixo, grind it and then glass back over it, so that the end result is that you are drilling through a solid surface instead of your core. This procedure eliminates the concern of a possible leak into your core due to a faulty sea cock installation.

I hope that this is clear and as always please don't hesitate to contact me directly at the factory at anytime with questions or concerns.

Sincerely,

Scott Boysen
 
Well, this unless anyone wants to argue, it looks like the factory has it going on. Personally, I have not regretted buying a C-Dory- balsa core or not.

sjboysen":2jgoispb said:
Good question and an age old one. I guess the simplest way to answer it is that no matter what core is used, if it is not laid up properly or cut into properly it will not last. We use balsa core that is vacuum bagged into place on all Cdories, and foam core that is vacuumed bagged into place on all the Venture models.

When doing a thru-hull for a seacock the proper procedure which we utilize here at the factory, is to back cutout 3 times the diameter of the thru-hull and then fill with thixo, grind it and then glass back over it, so that the end result is that you are drilling through a solid surface instead of your core. This procedure eliminates the concern of a possible leak into your core due to a faulty sea cock installation.

I hope that this is clear and as always please don't hesitate to contact me directly at the factory at anytime with questions or concerns.

Sincerely,

Scott Boysen
Click to expand...
 
Nope. No regrets. Every time I start worrying about the balsa core I think back to the pictures Red Fox posted years back of the water draining out of the inside of his hull. Drip, drip, drip for days. He had worn through the outer layer of glass on the bottom from parking on the PWS rocks and ice and was preparing to reseal it. He is no dummy and he certainly doesn't baby the RedFox, and to the best of my knowledge it is still floating and has never given him grief.
 
Well, I've griped about balsa used as a core on this forum. When I saw the extent of the rot in my transom due to the engine bolts improperly installed I went ballistic about balsa. I think I likened it to a nuclear power plant - when all is fine, no problem; but a little problem turns big in a hurry...

That said, through a fair amount of research on boatbuilding over the past two years, I'm quite convinced that a balsa/fiberglass sandwich is a great combination - quite strong and light. The important thing is to keep that balsa dry. Doc Austin's recommendations on how to treat any fiberglass penetrations are corroborated in all of the books I have on the subject. Dry balsa seems to be great stuff; if you keep it that way you'll have a nice boat for many years.

Seems to me that it comes down to how much effort one is willing to expend to ensure that any cored fiberglass penetration is treated just so. Some of us are willing and interested, some have other interests and priorities and don't want to spend their time on those kind of tasks. I think it's important to assess your level of interest in boat work vs. the type of core material in the boat you're about to purchase.

I guess we all have to find the balance appropriate for our boating lifestyles.
 
One thing to also realize is that a lot of what winds up on the boat is rigging that's typically done at dealer. The dealer's processes are not necessarily good and they often have a lot of cabling etc. to run. There's a lot of minor items on Meant to Be that were done by Cutter Marine and which I will eventually get to (most involving penetrations through the foam cored transom).
 
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