I don’t post too much these days but I’m always lurking and usually wait 'till i feel like i’ve done something fun to post it up on here, so here’s the latest offering!
I’ve been on a small quest for GOOD flex in a board, not just flex, but the right direction, angle and return…I’ve over engineered a few boards on the way and was afraid to do the same one more time, but I’m pretty sure I didn’t even if it looks like I did
The core is 1.5 lb EPS, the bottom 5.7 oz Kevlar (twill weave) was vac bagged onto the bottom with no laps, then the Paulownia deck patch was routed into the deck. I glassed the top with the same Kevlar and a 2oz (regular glass) cap, both lapped to the bottom; the kevlar short, and the 2oz longer to cover it. All layers were laminated with Resin-X which is a really cool Polyurethane resin, it was difficult to work with in my situation, but TOTALLY worth it (check out the video at the bottom).
I don’t think it was any one of the materials or things I put into it that made it do what I wanted, but all of them together worked out really nicely I think…it looks like crap before it’s ever been rideen, but somehow I’m happy about that…all function, no form.
I did a semi thorough build documentation on my blog if you want more info on the steps and process!
That's some nice brainstorming there Ryan. It made a lot of sense once I saw what you did. The proof is in the pudding and the video shows clearly that you got what you were after.
the fin mold is a 4a template, the fin on that board is one with the base cut away and the tip thinned; the mold isn’t nearly as upright as a nail or whale fin:
I took the biggest fin i commonly used and molded that one in order to trace the rest of my templates inside of it…bingo!
yah, HUGE bumer on that one 'cause it looks soooo nice
I wanna make sure it doesn’t buckle or crack or do anything weird before I paint it, so far the bondo has had a little troubles but its not the end of the worl…now have to decide which color she’ll be.
In the real world Kevlar is used to stop bullets in bullet proof vests so it helps with penetration or impact damage other then that it makes boards heavier.
It's also very expensive compared to regular glass and seems more like a gimmick to real in suckers or in this case used for special applications.
Not sure what properties it really adds on normal boards most of my boards delaminate over time and no special fiber will stop that.
in my process i was looking for a material that would be there for dings and water resistance, but let the board flex where it wanted to…i engineered a lot of weakness into this board and then reinforced and tuned the flex from there; essentially building the flex pattern into the board, as opposed to taking it out like some of my other experiments.
I was looking for weakness and it sure does bend, the resinx does a really good job with it and giving it some snap; the board’s got a lot of tension in it and really gives way on a cutback but snaps back just as quickly as you’d ever need it to.
Reading through some old notes I've found this....Kevlar has very high tensile strength, poor compressive strength and is just over half the weight of glass. So put it in the right place and it is great and adds less weight than the same area of glass (you can use a lighter cloth to get the same tensile strength). It is also able to stretch much further than glass before failing. But you cannot sand it effectively.
great stuff ryan. sabs told me he did a kevlar eps board when he was sailing his 50 yacht he built around the world . he built it on the yacht i think and told me tha the used to literally throw it into the tender from the boat, and treated it like rubbish but it held up the whole trip without a ding. kevlar and paulownia is combo ive been itching to try. cant find the video of you surfing it tho the link goes back to your thread. loving the tail flex you got there
no doubt, your a real talent. would love to watch you work one of these days. you dont snowboard by any chance? surfings my missus and snowboardings my fluff on the side that im thinking about moving in with.
