yes, clearly balsa would rot when wet where as the core cell would not. Presumably the latter would just delaminate much like a blister? Is the advantage of the foam core that any moisture intrusion would be more localized? Is there a weight and/or cost benefit? I would guess the balsa would have greater insulating properties however the foam would add some strength?
So much knowledge on this list.... John Sent from my iPad > On Mar 1, 2014, at 4:29 PM, "dwight" <dwight...@gmail.com> wrote: > > Balsa core rots when it gets wet but it is quite strong on end if > ebcapsutaed but a solid surface like a several layers of glass matt in cured > polyester or other resin...aligned E glass fibers used with knowledge of > where the stresses are highest offer more tensile strength than chopped > strand and consequently less are required so lighter weight construction can > result and have the same or better strength. Kevlar fibers have very high > tensile strength and used as Kevlar matt in a resin laminate has good > resistance to impact damage and is also very lightweight, carbon fibers are > very lightweight and have high tensile strength as well, but the best > results are achieved with proper alignment of the fibers corresponding to > the direction of highest stress > Just a guess > -----Original Message----- > From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of > j...@svpaws.net > Sent: March 1, 2014 3:27 PM > To: cnc-list@cnc-list.com > Subject: Stus-List Help understanding composites > > I'm but an accountant not an engineer. Help me understand this stuff.. > > So if I use a 1990 34+ as the baseline, the hull was a composite of vinyl > resin, presumably glass matt and chopped strand, balsa core and Kevlar. > > Now fast forward to 2000 and my early 121. The glass Matt has been replaced > by E glass, balsa has been replaced by core cell, glass strand remains to > add bulk and the Kevlar remains. Presumably this provides a lighter hull as > the e glass is stronger than matt, core cell is lighter than balsa and > requires less resin and the Kevlar remains the same. > > Fast forward another 10 years and we have epoxy, reinforced with carbon > which does the job of Kevlar, matt, e glass and strand. The core cell > remains. > > Am I even close? > > John > > > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > CnC-List@cnc-list.com > > > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > CnC-List@cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
