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Snowbird's orphaned Charger 16DL
http://www.hpbc.ca/viewtopic.php?f=20&t=1367		 Page 7 of 7
Author:  BoomerMuskoka [ August 19th, 2013, 11:23 am ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
floridacharger wrote:
Oh yeah, forgot to ask. I'm thinking that if this goes well, i should be in the water in a few months. You'll b freezing up there by then but I would like to bring the boat up to gravenhurst next summer. I can get a free ride on Amtrak Auto Train to Lorton, Virginia which is 10 hours south of gravenhurst. The wife has been bugging me to see niagra falls which is right on the way. When is the best time to come up, see some racing, and show the DL her roots:))) I work best when I have a timeline.


july is the boat show month, antique is first week, then the in water boat show is third week,, im not sure what the exact dates will be next year but plan for early to mid july , and keep an eye on it http://muskokashows.com/ there is so much to see im muskoka, iv lived here 25 years and still find new parts of it every year.. ;) once discovered never forgotten :lol:
Author:  floridacharger [ August 22nd, 2013, 2:35 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
Read the book- not much help. Second half was mainly about airplane construction. First half was good. Made me revise the core stack. Strakes will be: soric-4X 28oz uni-12mm IG balsalite-4X 28oz uni. No need for 45* or 90* bias on 2" wide core. All uni should make strake core sandwich pretty friggin stiff. Center/ bottom will be:3mm soric-facing-12mm IG balsalite-facing-12mm balsalite-facing. i changed the facing layups from all triax to a layer of 40oz uni, a layer of 36oz triax turned 90* (for +/- 45 and 90* bias), another layer of 40oz uni, second layer of 36oz turned 90*, and a third layer of 40oz uni. This works out to 120oz of cloth at 0*, 17.7oz of cloth on both 45* axis, and 33.4oz of cloth on 90* bias. I have nothing to back up this design as far as facing strength vs. core strength but it has to be better than the wet balsa that was in there. I'm also going to make a sample core infusion on a sheet of glass so I can be sure of complete resin distribution though both core thicknesses.

Something else-in the book, he states in bold capital letters that "DO NOT FAIL TO BOND THE PIECES OF CORE TOGETHER! FAILURE TO DO SO WILL iNVITE STRUCTURAL FAILURE." Says that "If two adjacent pieces of core are not structurally attached, the juncture is not capable of transmitting shear loads through the core, and they must be carried by the skin in secondary bending. This means of carrying the load is very dangerous, as it generates peeling forces which tend to separate the skin from the core, thereby causing a general failure of the structure in the area." (Andrew C. Marshall, Composite Basics, 7th edition). It makes sense to me after reading it but would never have occurred to me on my own. Safety issue in my eyes. Felt the need to pass it on.
Author:  Blizz [ August 25th, 2013, 1:18 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
Boomer do not use NidaCore below the waterline. While it is a great lightweight core it is NOWHERE near as impact resistant as they would like you to believe. I have installed and replaced way to many sqft of honeycomb from 1/4" to 8" thick made from nomex and aluminum. It can be vacuum bagged but you need to use film adhesive. And florida why are you wanting to use 2 layers of core that's just one more place for the layup to fail? There is no real ratio between skin and core thicknesses, I've seen anything from 1 layer to 10+layers. The change you made in layup going to 3 layers 0-90-45 is the same as triaxial, althought I prefer that or 2 layers of biax. people were seeing more failures out of triax than singles and biax. And while most of my experience is on aviation it's not as different as a lot would like you to think either.
Author:  floridacharger [ August 27th, 2013, 1:54 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
Hey Blizz, thanks for the feedback. I was under the impression that the only way to get a 90 degree bias was to turn the fabric 90 degrees once the fabric was cut from the roll-thereby changing any 0* fibers to a 90* bias. I thought triax was comprised of fibers going straight(0*), fibers slanted left(+45*), and fibers slanted right(-45*). I'm using stitched cloth if that matters. According to the book, tensile strength is only achieved along the axis of the fibers. That is why I'm putting so much emphasis on the 0*(bow to stern) because that seems to me to be the primary bending force when you're haulin' ass. Am I wrong?
Author:  BoomerMuskoka [ August 27th, 2013, 3:38 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
Blizz wrote:
Boomer do not use NidaCore below the waterline. While it is a great lightweight core it is NOWHERE near as impact resistant as they would like you to believe. I have installed and replaced way to many sqft of honeycomb from 1/4" to 8" thick made from nomex and aluminum. It can be vacuum bagged but you need to use film adhesive. And florida why are you wanting to use 2 layers of core that's just one more place for the layup to fail? There is no real ratio between skin and core thicknesses, I've seen anything from 1 layer to 10+layers. The change you made in layup going to 3 layers 0-90-45 is the same as triaxial, althought I prefer that or 2 layers of biax. people were seeing more failures out of triax than singles and biax. And while most of my experience is on aviation it's not as different as a lot would like you to think either.


thanks for pointing that out again, i already posted it can not be used bellow the water line, its good to be clear... balsa is the best choice. :lol:
Author:  Blizz [ August 27th, 2013, 4:23 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
BoomerMuskoka wrote:
Blizz wrote:
Boomer do not use NidaCore below the waterline. While it is a great lightweight core it is NOWHERE near as impact resistant as they would like you to believe. I have installed and replaced way to many sqft of honeycomb from 1/4" to 8" thick made from nomex and aluminum. It can be vacuum bagged but you need to use film adhesive. And florida why are you wanting to use 2 layers of core that's just one more place for the layup to fail? There is no real ratio between skin and core thicknesses, I've seen anything from 1 layer to 10+layers. The change you made in layup going to 3 layers 0-90-45 is the same as triaxial, althought I prefer that or 2 layers of biax. people were seeing more failures out of triax than singles and biax. And while most of my experience is on aviation it's not as different as a lot would like you to think either.


thanks for pointing that out again, i already posted it can not be used bellow the water line, its good to be clear... balsa is the best choice. :lol:


Missed that one. Only seen where you asked. Sorry
Author:  BoomerMuskoka [ August 27th, 2013, 5:22 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
Blizz wrote:
BoomerMuskoka wrote:
Blizz wrote:
Boomer do not use NidaCore below the waterline. While it is a great lightweight core it is NOWHERE near as impact resistant as they would like you to believe. I have installed and replaced way to many sqft of honeycomb from 1/4" to 8" thick made from nomex and aluminum. It can be vacuum bagged but you need to use film adhesive. And florida why are you wanting to use 2 layers of core that's just one more place for the layup to fail? There is no real ratio between skin and core thicknesses, I've seen anything from 1 layer to 10+layers. The change you made in layup going to 3 layers 0-90-45 is the same as triaxial, althought I prefer that or 2 layers of biax. people were seeing more failures out of triax than singles and biax. And while most of my experience is on aviation it's not as different as a lot would like you to think either.


thanks for pointing that out again, i already posted it can not be used bellow the water line, its good to be clear... balsa is the best choice. :lol:


Missed that one. Only seen where you asked. Sorry


no problem,,im a newb :lol:
Author:  Blizz [ August 27th, 2013, 5:44 pm ]
Post subject:  Re: Snowbird's orphaned Charger 16DL
floridacharger wrote:
Hey Blizz, thanks for the feedback. I was under the impression that the only way to get a 90 degree bias was to turn the fabric 90 degrees once the fabric was cut from the roll-thereby changing any 0* fibers to a 90* bias. I thought triax was comprised of fibers going straight(0*), fibers slanted left(+45*), and fibers slanted right(-45*). I'm using stitched cloth if that matters. According to the book, tensile strength is only achieved along the axis of the fibers. That is why I'm putting so much emphasis on the 0*(bow to stern) because that seems to me to be the primary bending force when you're haulin' ass. Am I wrong?


Correct bias is 45* -45*, biaxial is 0* 90*
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