Bert uses diagonal timbers to help the board store energy when it flexes and then quickly return to shape (see daddio’s picture). I have been spending a lot of energy trying to get my rails looking perfect. I’ve been CA gluing the ends together so they have tight joints with the longest pieces of wood possible (in effect making them 1 long piece of balsa). My goal what to make the strongest possible rail. Bert’s looks to be the complete opposite. He used short pieces (1 - 2.5 feet) with little gaps between the joins. I think that his would make the rails more flexible.
I’ve been thinking about something else. Someone mentioned that they had picked up some balsa and some pieces were stiffer and some where softer. Could it be that Bert uses shorter piece to place pieces of wood with different flex properties where he needs it? Same with the diagonal layout, in addition to reduce twist, doesn’t allow for placing the wood of your choice at the right position? regards, Håvard
These two pics from the event intrigued me as I posted them over at Skurfer and didn’t seem to make sense unless…
in photo 1 showing the bottom rear of the kelly board you’ll notice that the short diagonal balsa pieces are joined symmetrically down the center of the board aligning to the stringer line. Also look how he joins the fins in these panels
Unless:
Bert is scarfing the diagonals with an overlap right down the center creating a stiffer “stringer-like” action down the middle for strength and making the sides more flexible than the middle. Imagine both diagonal board lengths being of the same size but dado’d at the joint forming a diamond overlap right down the middle…
or
Bert alters the overlap pattern where one side is longer than the other side differently between the deck and the bottom skin… Which would create a different flex pattern of the skins in reaction to the core.
Since I didn’t see them in person I can only guess what’s going on but either of these two choices in laying out the wood creates an interesting influence on how the board would flex…
Also long parallel patterns would tend to tie the nose to the tail versus diagonals would tie the center to the rail and create different flex pattern between the short(in back) pieces and long pieces (up front). Meaning the flex should be greater in front of the fins and less as you get closer to the tail just like those other aussie carbonfiber flex tail boards shown on “The Shapemakers”.
Some really interesting stuff he’s showing here
way different than the pics he released on sways in any of his threads…
Which I presume were board using an older technique…
Can’t wait to try this no overlap diagonal layup approach on my next project along with the Urethane glueing of prefabbed skins. I’ll do the diamond overlap in the deck and symmetrical layup in the tail starting at the classic 18" point up from the tail where the rail profile goes hard.
Gonna need to use alot more tape this way… Need to scarf the joints using a jig on a joiner to shave the 1/8" or 1/16" in half.
On second thought lookin at Bert’s use of the diagonal layups makes me wonder if CMP and us weren’t too far off in our use of this Lauhala pattern woven bamboo material. Just that our weave pattern is alot finer than what’s going on with the panels of balsa…
Maybe prefabbing some bamboo skins and then urethaning them on to a redesigned wide core shape with perimeter rails might us the flex we’re missing with all this epoxy construction we’re doing…
“For your inner glass pre wet it on a sheet of window glass,get every last extra drop of it with a squeege,Then when you peal it of the glass sheet to put it on the balsa inner side even more resin will be left on the glass.”
Sabbs, so after you squeegee the excess and lay it on the board, how do you fill the weave for a smooth surface, and doesn’t that just add back a lot of the resin weight?
Also, I’ve pre-wet some carbon tape for past boards and folded it into a neat roll, wet it and then wrung the darn thing out to minimize the resin. Do you lay yours out flat (full template) or do you roll or fold it up and then wet and unfold onto the board?
“For your inner glass pre wet it on a sheet of window glass,get every last extra drop of it with a squeege,Then when you peal it of the glass sheet to put it on the balsa inner side even more resin will be left on the glass.”
Sabbs, so after you squeegee the excess and lay it on the board, how do you fill the weave for a smooth surface, and doesn’t that just add back a lot of the resin weight?
Also, I’ve pre-wet some carbon tape for past boards and folded it into a neat roll, wet it and then wrung the darn thing out to minimize the resin. Do you lay yours out flat (full template) or do you roll or fold it up and then wet and unfold onto the board?
sorry to interrupt greg but he’s talkin about the inside glass between the balsa skin and the eps core…no need for smooth cosmetic finish…
couldnt sleep last night…tossing and turning with all these recent posts just got me brainstorming…need to chill the noggin and get some sleep tonight
nice boards cmp…i think both you and bert are doing innovative things…you guys didnt even know the other existed before a year ago or so…parallel universe?
this fat fish here is a double laminated. only because I wasn’t having any success putting on the hardwood veneers directly to the foam.
So it’s 4oz+1/16" balsa+epoxy(no glass)+hardwood veneer(Birch/Mahogany)+4oz S
And even though there’s no balsa rails it does have the full sheet of 1mm bamboo as a horizontal stringer and is anywhere from 2.8" tp 3" thick.
Funny part is everyone keeps saying how light it is… Whereas I’ve been thinking it was over kill with 5 separate layers of wood on it… So maybe your right… Maybe we’re seeing an inside out version on the K-board… That’s how he reinforces and distributes the load in the tail section under the lam’s he’s been showing us… Only Bert knows…
Oh yeah he does use a form of RDM I did a search and found a whole thread about it where he said he was doing it or something similar to control his resin saturation on this skins… I think everyone was confused at the time thinking he was doing RDM to join his skins to his core… I think he’s gorilla gluing them on or some thing similiar…
regarding the butt joints. That makes sense. cuz if you wanted consistant flex with overlapping balsa, you would alternate every other one making a consistant center point with the reflex being focused back to the rails.
What was up with the fcs Plugs? That’s heresy according to BB’s theology as found in the book of flex, chapter 9 verse 11. " man shall not live by fcs alone. but from more flexible fin box choices".
I think that I did my best snooping on Saturday! Bert wasn’t there so I spent about 2 hours studying the boards. It sounded like you would be able to buy boards soon over here. It was funny, my son what jumping up and down on one of the boards. A group of people stopped and looked shocked and told him that that he shouldn’t be doing that. You should have seen there faces when Bert came over said okay then proceeded to jump up and down on the board. I would never have thought that a board could stand up to so much abuse (think of the old Samsonite suitcase commercials with the gorilla jumping on it).
yea butt joints would definitely make it more flexible that the overlap style we’ve been doing…
Interesting on the sale of the models.
I’m sure once Nev and Bert are done with their capital hunting dog and pony show they’ll want to unload the prototype cargo before heading home…
Did I hear “sample sale”?
I guess there’s always hope.
Maybe the investment guys/houses get to keep the samples… Maybe Greg got one, or Swaylocks… At least someone here who could actually ride one and report back to the rest of the crew…
Some editor from Skurfer, Skurfing Mag, or Longboarder should go down to Baja with Bert and crew and do a story about it all…
I spent most of the day onsite Friday. According to “Bernie” ( Sunova’s production manager and longhair in Daddio’s photo) the diagonal orientation was cosmetic. I was concerned about this as my board (which didn’t make the flight) was the nose to tail design.
Several of the boards were without fins or vents and in fact finished at ken’s (airframe) the night before. We were wetsanding them in the surf during trial heats. Several of these boards were to showcase the ability of custom graphics/advertising etc. I understand Josh (speedneedle) is going to be doing some art for them. Several other boards were crews including “Rocky” and another P.B. San Diegan’s.
I was hoping to surprise the Cerritos crew with a Sunova, but BB’s work and play won’t allow it. From what I have read I’ll still be seeing cutting edge…it just wont be under my feet in the water.
While I have fun surfing any type of watercraft, I can definitely see why custom sandwiches get many so fired up… Gil
noticed in the K board photo on the rail,the grain at the tail looks different to the grain in the middle …could be a slab sawn /quarter sawn variation…
one of my first posts suggests this to be relevant …
