Coosa is an excellent product for a core. Expensive it worth every penny Sent from my iPhone
> On Sep 17, 2021, at 11:55 AM, Neil Andersen via CnC-List > <cnc-list@cnc-list.com> wrote: > > > Some of the new coring material (divinicell??) is supposed to address the > balsa/foam issues. > > Anyone with specific knowledge?? > > Neil Andersen > Rock Hall, MD 21661 > 484-354-8800 > From: CHARLES SCHEAFFER via CnC-List <cnc-list@cnc-list.com> > Sent: Friday, September 17, 2021 10:39:29 AM > To: Stus-List <cnc-list@cnc-list.com> > Cc: CHARLES SCHEAFFER <cscheaf...@comcast.net> > Subject: Stus-List Re: Balsa core history > > That's a great story about Pearson starting the end grain orientation. I > wonder if that's 100% true. I'll bet several others would have thought of > that as well. Anyone who works with wood knows the compression strength is > best when wood grain is oriented that way. Honeycomb cores are end grain > oriented for the same reason. > > I read an article I can't seem to find again, that compared balsa to foam as > coring and they determined the balsa was better; stronger bond because the > end grain wicks up resin, lower cost, better for the environment too, as it's > a renewable source. Coosa board has better water resistance but it's so much > more expensive; it comes in sheets that add to shipping costs. ContourKore > Balsa is a series of cut squares, attached to a scrim that can be rolled so > it packs into a smaller package and ships for less. I used balsa to replace > wet core on my boat. Some of the wet balsa still had a very strong hold on > the fiberglass, and I had to use a chisel to pry it loose and an angle > grinder to smooth the remnants off. Pretty amazing stuff. > > Chuck S > > >> On 09/16/2021 6:21 PM Lisle Kingery, PhD via CnC-List >> <cnc-list@cnc-list.com> wrote: >> >> >> FWIW, this prompted me to take a look at the book "Heart of Glass: >> Fiberglass boats and the men who made them": and some info on Balsa is on >> p122, >> >> "Balsa Core. The Baltek Corporation was the exclusive supplier to powerboat >> builders of balsa planks for stiffening hull sides and bottoms. When balsa >> was originally supplied in lengths with the grain running longitudinally, >> Pearson had problems with water migrating away from the point of entry at >> the deck hardware fasteners, causing delamination. Everett Perason recalls >> that "We were using pieces 3 feet long by 1/2 inch thick by 2 inches wide. >> We had some leaks at the fittings, which didn't make any sense. So I started >> stacking this stuff up and cutting it on the bandsaw and making end-grain >> balsa. I was doing that on Constitution Street when Alex Lippay and Bob >> Levine came in from Baltek. They said "What are you doing". I sadi "I got to >> turn this stuff the other way to stop the water from spreading. They said >> "Jeez, this is what we should be doing." I said "You're right". That's how >> Contourkore started. They took the end-grain idea and made samples that we >> evaluated. They came up with a method of putting scrim on it and so forth. >> In hindsight, I should have applied for a patent. I think we were probably >> one of the first to use Contourkore, as early as 1963 in a race boat hull. >> THe new product was brought to market in 1963 and 1964, with Pearson as one >> of the its first few users and most vocal supporters. Indeed, in 1981, >> Pearson sank a 2-square-foot basl cored panel in Narragansett Bay, attached >> by change to his dock. After three years he removed the panel from the water >> and had it analyzed. The results? No water penetrated the balso more than 4 >> mils." >> >> Best, >> >> Lisle >> >> On Thu, Sep 16, 2021 at 4:23 PM CHARLES SCHEAFFER via CnC-List >> <cnc-list@cnc-list.com> wrote: >> "Balsa core" gets some bad press and I was interested in how it came into >> boating, especially C&Cs. >> >> After some research, I learned: >> Making things with a core was first used by Egyptians three thousand years >> ago. Veneers of precious wood over a core of cheaper wood extended the use >> of precious materials. The practice was lost in the middle ages and >> re-imagined in the 1700's when furniture makers wanted to make things from >> scarce woods. >> >> Later in the 1920's and 30's, balsa core was being harvested in Equador by a >> French company trying to market it in France in the 20's and 30's. The >> Jewish French owners fled the Nazi takeover and emigrated to the US. Their >> balsa was later used by DeHaviland in England to build the famous Mosquito >> two engine bombers in 1941. Dehavilland built over 7700 of these 400+ mph >> planes using two Spitfire engines each. They used a plywood vaneer over an >> endgrain balsa core. https://www.youtube.com/watch?v=JTsnMKzmdWs&t=613s >> >> The balsa industry lost a market after WWII but in the 70's, they convinced >> fiberglass boat builders to use balsa core and Hatteras sportfishing yachts >> were their first big client. Almost all boat builders eventually started >> using balsa soon after, including C&C, Pearson, Santana, Cape Dory, >> Columbia, Catalina, Hunter, Olsen, Saber, Schock, J-Boats, Beneteau, >> Jeanneau, as well as all the power boat builders, too. >> https://www.company-histories.com/Baltek-Corporation-Company-History.html >> >> Core comparisons: >> https://www.cruisingworld.com/how/inner-layer-core-materials-sailboat-construction/ >> >> >> I personally think C&C did an industry leading job to perfect the process >> using fiberglass and balsa core to build a lightweight and strong structure, >> but that is better covered by John Kelly Cuthbertson or others with more >> personal knowledge. >> >> >> Chuck Scheaffer, Resolute, 1989 C&C 34R, Annapolis >> >> >> Thanks to all of the subscribers that contributed to the list to help with >> the costs involved. If you want to show your support to the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - >> Stu >> Thanks to all of the subscribers that contributed to the list to help with >> the costs involved. If you want to show your support to the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
