Can o' Worms

[Bardo]

Okay,
I know some of what I am going to hear, if previous threads are an indicator.The topic is C-Flex. I would like to hear from those that have knowledge of its PROFESSIONAL use. I am looking at a boat that is 1959, mahogany over oak hull, which the owner had C-Flexed a few years ago. The boat is completely restored and appears in tip top shape. Is there any reason to suspect that a properly installed C-Flex sheath over good wood should pose a particular problem? I have reviewed the threads here, but would like to hear about the product in a quality controlled process over a sound hull.
Thanks,
Freeman

[Tartan34C]

It hasn’t worked out in the long term because of the different properties of both materials. Wood changes dimension with the changes in moisture content but fiberglass doesn’t. At some point you get a breakdown between of the bond between the two and rot sets in.

C-Flex is a good fast way to one-off a boat with only a simple jig instead of a mold. I don’t think it’s a very good way to preserve a boat but it might be a good way to extend the life of a tired wood boat with the understanding that it will destroy the underlying boat in the end.
All the best,
Robert Gainer

[CharlieCobra]

While JeffH does not like C-Flex or any system of glass sheathing for good reasons, I've spoken with various other boat restoration professionals about the systems. They've all come to the same conclusions. The integrity depends on the original state of the wood at the time the sheathing was applied. If the wood was thouroughly dried, in good shape and possibly refastened at that time and the sheating properly applied, the hull should last a very long time. There is however, the very real issue of water getting between the sheathing and wood from the inside and causing rot later.

[CharlieCobra]

Originally Posted by Tartan34C

C-Flex is a good fast way to one-off a boat with only a simple jig instead of a mold. I don’t think it’s a very good way to preserve a boat but it might be a good way to extend the life of a tired wood boat with the understanding that it will destroy the underlying boat in the end.
All the best,
Robert Gainer

C-Flex CAN be removed but it's difficult at best and you WILL destroy a percentage of the planking. Can ya imagine stripping of an entire hull of IBM 5200? I would go over to boatdesign.net and ask some questions as well as woodenboat. Plenty of very knowledgeable folks over there with regards to this area.

[Tartan34C]

Originally Posted by CharlieCobra

While JeffH does not like C-Flex or any system of glass sheathing for good reasons, I've spoken with various other boat restoration professionals about the systems. They've all come to the same conclusions. The integrity depends on the original state of the wood at the time the sheathing was applied. If the wood was thouroughly dried, in good shape and possibly refastened at that time and the sheating properly applied, the hull should last a very long time. There is however, the very real issue of water getting between the sheathing and wood from the inside and causing rot later.

Unfortunately we don’t see eye to eye on this question. If the boat was dry when the glass was applied it won’t stay that way in service. Boats are in water and get wet so hoping to keep the wood dry is an exercise in wishful thinking. I don’t know of any long term survivors that were glassed.
All the best,
Robert Gainer

[CharlieCobra]

Check this link out, good info there.


http://www.daviscoltd.com/nams/Documents/nvic7-95.pdf

[CharlieCobra]

Another thing to take as "What it's worth" I've searched diligently for published accounts of failure of C-Flex hulls without finding a single thing on the net anywhere. Ya figure, if these hulls were failing, someone would've written about it up here by now. I mean, they write about everything else in the world.

[camaraderie]

The all failed before the internet was invented!! (g)

[Tartan34C]

Now I am confused CharlieCobra. Aren’t you a case of someone describing on the internet a failure in the system? You posted some questions on the boatdesign.net sight describing local failure due to rot in the substrate. Or did I misread the conversation? And if I remember the answers you got the majority were not very encouraging and some of the most experienced professionals had the most negative voice. edit 10-23-07 at 6:19 PM EST ***I did misread his post at boatdesign.net. See his post above.***

Interesting reference you posted. Did you read it? It describes C-Flex used as a different system then you have, a system I have never seen and not the way it was used in your boat and doesn’t paint a very encouraging picture either. As I said it’s a way to squeeze out more life in a tired hull and as long as it holds up the CG will certify it as OK for a passenger vessel. But that paper doesn’t say you gain anything long-term. It simply says they will let you use it if you want. I stand by my statement and maintain that it’s not a good thing to do if you want long term preservation as opposed to short-term flotation.

And by the way, I think you don’t read much about C-Flex on the net pro or con because it was at its most popular in the late 60’s and early 70's when the internet didn’t exist and even then only a handful of people tried it. And the conscience was that it was not worth doing so you don’t see very many people trying it now that the net has become popular. So not much is on the net about it one way or the other. I built a boat with it in 1975 and it was a fast and easy way to get a hull. But there are now even better ways to build a one-off so I don’t even consider it for that anymore. As far as I am concerned it’s just a footnote in history now.
All the best,
Robert Gainer

[Tartan34C]

Originally Posted by CharlieCobra

C-Flex CAN be removed but it's difficult at best and you WILL destroy a percentage of the planking. Can ya imagine stripping of an entire hull of IBM 5200? I would go over to boatdesign.net and ask some questions as well as woodenboat. Plenty of very knowledgeable folks over there with regards to this area.

Anything can be done with enough effort and time or money thrown at the project. But I don’t understand where you are going with this thought. I don’t think its practical to backup a step and remove it in most cases. If the boat is worth something in a historical sense then a restoration may be worthwhile but most boats that got the treatment weren’t worth the cost of traditional repairs so the quick fix was used. Remove the C-Flex and now you need to rebuild the boat unless the C-Flex was applied unnecessarily in the first place. If that's the case now you need to repair the surface damage from the C-Flex after removing it.
All the best,
Robert Gainer