next »

[SURFFOILS]

Just an excellent set of posts guys, everyone here is looking to the future and willing to work together.
Ideas from 'outside the box' followed with  helpful and hopeful suggestions/links.
Congratulations, it doesnt always look like this on the 'net ! 

I'm very glad I joined up.
SF.

[Bernhardt]

Thanks Paul.   I hadn't thought about the idea that not adhering the layers
of the core (except around the edges) might allow one to skip the vent... enticing  

I've now started over from square one because I accidentally adhered my blank to my
rocker table (aka longboard) while vacuuming on the rails (whoops!!!) and I had to
destroy about 3 feet of the blank to detach it.  Not what I hoped for, but in the process
of breaking it, I learned some things about the strengths and weaknesses of the way I
did my rails, so I should be better equipped for next time. 

In case my failure can help someone else, here's what I learned: 
I used 3/16" and 3/8" balsa for the rails, depending on the amount of curvature.  As I was only making the rails 9/16" thick, using 3/8" balsa was a mistake because there wasn't enough reinforcement where the 3/8" balsa joints were.  Next time I'm gonna use 4 layers of 1/8" instead so that the joints don't create such weak spots.  Also, I used 3M super 77 to glue the rails, which made the process easier, but might have not been the best choice strength wise.  When I first took it out of the bag the joints were reasonably strong, but after sitting out in the sun a couple days some of the joints began to separate, so the longevity of the rails would've likely been less than if using a titebond III or epoxy.  ( I had to leave a titebond III wood joint under water for a month before it started to weaken. Also, I read a woodworker magazine article testing glues in which titebond III and epoxy outperformed other options, especially foaming PU)

I think I'll try leaving the center of the core detached on my next board
unless someone talks me out of it.  I wasn't planning on it because I figured
that since I'm using 30mm 1.3lb EPP for the bottom layer, which is
considerably less rigid than the EPS, the shear forces wouldn't be as
much of an issue as using all EPS.  But I suppose it might help a little,
and not needing a vent would be nice.  Plus, if we really wanna split hairs,
less adhesive = less weight.  I wonder if that was any part of Sabs'
motivation, apparently being the king of lightweight.

Has anyone tried the EPP bottom?  Just curious. 
When I ordered the EPP, I planned on doing the whole board with it, but decided it might not be rigid enough for the deck, at least unless I were to use thicker balsa.   I made a test piece about 1.5" wide, 18" long, and 2.25" thick EPP with 1/16" balsa skins and 2oz glass inside and 4oz glass outside, using RR 2020.  If I stood on it with my heel (170lb) it compressed about an inch, which seemed like too much to me.  The cool thing about EPP though, is that it springs back to its original form, with no dents.  The 2lb EPP might work well, but I didn't want anything that heavy.  It's also cool stuff cause it's less affected by water and it is quite recyclable.  However, it's less rigid and a bit more spongy than EPS, so that has to be considered.  At some point I'd like to try an all EPP board with a thicker deck skin, but I may wait till I can find a good nearby source for the 1.0lb EPP.  Because of the decreased shear, this might have results similar to the desired results of the original post on this thread.

If anyone wants to play around with EPP, I got mine from http://rcskyflyer.com/ (near LA)
and they had excellent customer service.  It comes in 3' x 4' sheets, which I had no problem gluing into
a blank home-depot style using RR epoxy and microbubbles with a vac.  Formed a bond stronger than
the foam too, in spite of the fact that many things don't stick to EPP.  If you're somewhere far from LA,
I might know of a supplier closer to you because I came across several while looking for one that was
close enough for cheap shipping.

I think the guys you want to talk to or email about regarding shaping or using EPP would be Jim Richardson or Jeff Johnson at Surflight.

I can see using it as a secondary layer over a stiffer HD core like they do or as a core surrounded by a stiffer layer before skinning it. It's interesting stuff for sure with it's high elasticity memory and water proofness. Pretty much a misunderstood and under utilized material in this sport. Probably only Jim and Tom Morey truly understand it's capabilities regarding surfcraft.

How does it take to glassing?

[SURFFOILS]

I think it would work as far as assembly, but I wouldn't see any benefit to not tying the skins to the core.    It would allow way more flex, but it would severely weaken the whole thing.   

I've thought about this myself, and I blew it off after some thought experiments.

Mentally take three layers of balsa wood and just stack them together, no glue.  Flex them, puncture them, and karate-chop them until they break.   Now do the same thing with a stack of balsa that is glued together.  Much tougher.   A more accurate experiment would be to use some eps as the meat in the sandwich.   

It seems like without the skins tied to the core you could literally put a foot right through the board.   Without the I-beam effect of everything being tied together, it is just a stack of individually fairly weak materials.

  Guys, I too have thought about this and maybe, (and this is just a suggestion), if the central area core, possibly defined by a large springer outline, was attached to the skins but the perimeter of the core was not.

 The reverse of what was the initial idea of this thread.

 That would give a bullet proof central area for the surfer, with a firm rocker under the surfer but allow the sides, tail and to a lesser extent the nose area to flex and adapt to the forces of the  wave. These areas , to my mind, are the most important areas where flex is required rather than having a variable centreline rocker along the entire length of a board when only the tail and inside rail is in the water.
 Much the same way that all boards currently have a central area that is thicker(foil) and wider( outline)  and the perimeter is thinner and more curved in outline to allow the board to turn, my idea would be to enhance this common design characteristic by introducing flex in the areas where its most effective.
 I realise that, to a degree, this is already the case in CS and other  boards but Im advocating a more finite degree of control through specialised design construction.
 Possibly through the use of totally 'area specific' molded components and materials then each area of a board would be truly purpose built. A true composte of individual parts.
 Compsand construction is already leaping ahead  and Id like to hear other peoples ideas and thoughts of the future too.

Regards, Brett.

 Edited: for mistakes and clarity.

[Bernhardt]

I think it would work as far as assembly, but I wouldn't see any benefit to not tying the skins to the core.    It would allow way more flex, but it would severely weaken the whole thing.   

I've thought about this myself, and I blew it off after some thought experiments.

Mentally take three layers of balsa wood and just stack them together, no glue.  Flex them, puncture them, and karate-chop them until they break.   Now do the same thing with a stack of balsa that is glued together.  Much tougher.   A more accurate experiment would be to use some eps as the meat in the sandwich.   

It seems like without the skins tied to the core you could literally put a foot right through the board.   Without the I-beam effect of everything being tied together, it is just a stack of individually fairly weak materials.

  Guys, I too have thought about this and maybe, (and this is just a suggestion), if the central area core, possibly defined by a large springer outline, was attached to the skins but the perimeter of the core was not.

 The reverse of what was the initial idea of this thread.

 That would give a bullet proof central area for the surfer, with a firm rocker under the surfer but allow the sides, tail and to a lesser extent the nose area to flex and adapt to the forces of the  wave. These areas , to my mind, are the most important areas where flex is required rather than having a variable centreline rocker along the entire length of a board when only the tail and inside rail is in the water.
 Much the same way that all boards currently have a central area that is thicker(foil) and wider( outline)  and the perimeter is thinner and more curved in outline to allow the board to turn, my idea would be to enhance this common design characteristic by introducing flex in the areas where its most effective.
 I realise that, to a degree, this is already the case in CS and other  boards but Im advocating a more finite degree of control through specialised design construction.
 Possibly through the use of totally 'area specific' molded components and materials then each area of a board would be truly purpose built. A true composte of individual parts.
 Compsand construction is already leaping ahead  and Id like to hear other peoples ideas and thoughts of the future too.

Regards, Brett.

 Edited: for mistakes and clarity.

You describing what Jim Richardson has already doing for years at Surflight.

http://www.surflight.com

A custom shaped blue dow core shaped in the shape of a coil spring arm similar to a suspension arm in an auto. Then vacuum bagged glassed in epoxy and carbon fiber using different orientations of glass and beefed up to stiffen up in areas that need it with more CF. I think he uses Proset epoxy.


Around this is laid a thick shell of polypropylene foam to foam an rough blank which is hand shaped to final form.  This is then coated with many layer of urethane to seal and protect the polypropylene. 

FCS plugs are inserted with epoxy resin for fins.

Flex stiffness is governed by the shape and thickness of the blue dow XPS core which is basically shaped like the camel back profile(thinned out and curved nose and tail) as  shown by Meecraftee over at swaylocks.

really next gen in my opinion and if you factor in some of the Nida core stuff Morey's using and the Basalt glass Bert and Holly were investigating a couple years ago, you have a very modern design concept. Up to the same level as other high performance sports equipment out there.

unfortunately, no one really gives a hoot except a dedicated core group of high income repeat clients which keeps Jim perfectly happy.

definitely not main stream I guess..

[SURFFOILS]

You describing what Jim Richardson has already doing for years at Surflight.
[/quote]



 Thanks, After a quick look at the Surflight site I can see that my idea is not new, thanks for the link !
Brett.

[StrangeBrew]

the only boards I've ever had delam were boards where I put a number of sheets together to get the overall thickness I desired, and used Super77 or another tack based adhesive to lock the pieces together.

Guess what; all of these boards; every single one of them (4 I think?), delammed in the middle of the board and vented or not, I was always dealing with a bubble. Believe me when I tell you that while you might want a core that is weak in shear, you definitely don't want any part of your core to have 0 strength in shear; you WILL have failure... 0.75# EPS is pretty damn weak in shear....and half the density of the lowest available EPP according to the RCskyflyer site....

The real way, I think, to do it, if you want to have a puncture resistant structure would be to have a fully EPP jacketed EPS core in the middle for shear properties, and then your sandwich skins. I bet you could easily build up a structure using this method that wouldn't require glass and would still have adequate stiffness. Bernie, I'd be very surprised if those surflights aren't very prone to skin punctures....am I wrong?

That said, it'd be a major pain to assemble that core, and it'd take a couple of iterations to get it "right". When one thinks about how simple it is to make a pu/pe board, how well a properly shaped and glassed pu/pe works, and how long a properly glassed pu/pe can last, I strongly begin to question the merits of the potential construction for any reason other than "to have something different"....not to be a downer or anything....

[paul cannon]

i think its trial and error on different combos can be worthwhile
and then once you have something that rides nice
then you can always refine the system

i dont think pupe rides that good anymore
feedback on my last board was that it was a lot better then the board he was riding
which was a machine shaped pupe pro model from biggest name  shaper in NZ
and its only number 27 or something
materials are undoubtedly superior
cuz its certainly not my design or shaping skilz

im am going to play with some layered cores my self
using xps as the perimeter foam and eps in the middle

personally im with bernie
i do think gary young an Jim R are a long way ahead
xps has a lot of possibilities

[Bernhardt]

The real way, I think, to do it, if you want to have a puncture resistant structure would be to have a fully EPP jacketed EPS core in the middle for shear properties, and then your sandwich skins. I bet you could easily build up a structure using this method that wouldn't require glass and would still have adequate stiffness. Bernie, I'd be very surprised if those surflights aren't very prone to skin punctures....am I wrong?

That said, it'd be a major pain to assemble that core, and it'd take a couple of iterations to get it "right". When one thinks about how simple it is to make a pu/pe board, how well a properly shaped and glassed pu/pe works, and how long a properly glassed pu/pe can last, I strongly begin to question the merits of the potential construction for any reason other than "to have something different"....not to be a downer or anything....

No delams like that so far
but we're epoxying or PU gluing the sheets togethor and it's always 2" on top and 1" on the bottom so the joint and  horizontal springer/stringer is no more than 1" if not less from the bottom skin.

so why HD and Lowes..
In my eyes surfing's great emancipation is when it can finally free itself from being dependant on anything 'surf industry" related. Only then will it get back to its source. I can see that in the growing family of hollow wood builders. The innocense and freshness is still very much in how they view what they are doing as they focus on the build and not the marketability of the end product.
 
And yes you're right about puncturing the Surflight's urethane skin with sharp projects but brush on a little urethane or squeeze on some silicon sealant and it's patched.. No water intrusion because of the EPP layer. They still are a weird animal to ride, kind of like driving around in a Caddy or Lincoln Continental versus a Bimmer or Miata.  The ride is very muffled with very little vibration transferred to your legs which is not always a great thing if you need to feel what your board is doing..  Super smooth though as you don't feel the speed.

There's a post from Holly in Swaylocks back in 2003-2004 where he says what he thinks about his Surflight and I think it said a lot to me back then.. Holly, Bert and Jim were all involved in material discussions with some Boeing aerospace folks back then so they were aware of what each of them were doing in their specific ventures. The backend behind the scenes sourcing aspect of all this is alot more connected than we would be allowed to believe.

That's the beauty of being in this to play around with the tech. I still buy and will continue to buy all my "regular" boards from local gurus who'll make them for me. I hope to ask Gary Young make me a board as well one day real soon and one day I'll hope to have a Sunova to add to my collection to compare as well. I'm lucky I have the ability to see for myself how alot of the hype pans out and it's opened my eyes to alot of what could be versus really happens.. The more you experience I think the more you find that other than durability and friendliness, none of it really matters. It's still a board on a wave and what you get out of that experience is really up to you nothing else.. That the secret of surfing one eventually get's enlightened to after years of hopeless ego searching. Some find it sooner than others, but eventually we all get there one day.

Since I still  buy from the best and don't expect to sell any of my own creations, it really opens the door with what we can  fool around with and learn from. That's the beauty of it all cause we learn a little bit more with every one we build and pushing the envelope with materials and construction techniques just helps us appreciate the work of those we still ask to make our "normal" boards for us.. There's a tremendous freedom achieved when there's no expectations of money to be made from what you do for fun.

I wouldn't do it any other way.