Hello, I've got a heavy crappy made-in-China longboard blank (it was too cheap to refuse at $15). I want to use it but somehow lighten it up a good deal. The stringer is about 5/16 down the center in some unknown wood. I'm contemplating shaping it, then cutting (possibly hotwiring) down each side of the stringer and removing that bit. This will leave me with a less stiff shape, but I am (at this time anyway) lazy to get someone to resaw some wood for a proper stringer.
The blank also has very little rocker anywhere.
So... I'm hoping that I can use a lighter glass schedule, and during lamination, bend some rocker into this board. I think a kevlar or carbon tape or two down the deck and bottom will stiffen the board, provide some back foot dent resistance (I'm really dismissive of expendable boards) and maybe, just maybe, chicks will dig it. Always a plus, right? My wife doesn't follow Sway's to my present knowledge.
Okay, but where can I obtain carbon or kevlar tape at the most reasonable price? I want to use 2-inch or 3-inch wide tape. Kevlar seems to be available in two weights: 1.7 and 5 oz/square yard. Carbon tape available in 5.7 oz/SY
West Marine wants $68 for 12 feet of 3 inch unidirectional carbon tape. OUCH! Where can I do better, or is anyone using these materials?
By the way, was that one of the 1st generation King foam blanks? I got 3 of those for $25 when he was dumping them. I had 2 with paper issues, but I can’t complain. He told me all the problems up front, and let me choose any blanks I wanted. I’d get more if he still had some, but he said they were all sold when I last asked.
I’ve scored really cheap PU off craigslist a couple of times too.
Also, you said the blank was heavy and were considering hotwiring the stringer out.You didn't say, but I'm guessing it's EPS. Not to insult your intelligence, but If it isn't DO NOT HOTWIRE IT!!!! Toxic fumes and fire are the result when cutting PU with hotwires.
Charlie, I have a couple of things to pass on… first try looking on eBay for CARBON FIBER CLOTH TAPE. I’ve looked there and I think you can get if for about $12/yd. I bought some carbon from Soller Composites last year. I think I got 4 yards of the 50" wide cloth, enough to cover a 10’ long board, for about $100 with shipping. I was going to strip my 10’ EPS board that is buckled and after reshaping the rails a little, glass it with Carbon. Just never got around to it.
Second, I’ve been toying with the idea of making a carbon fiber stringer. The plan is to lay out a couple of layers of the tape with the approximate rocker I want, and after it’s lamineted, clean that rocker/profile up. Then insert that into a blank.
I bet that would be a very strong and light stringer, a lot stronger than laying the carbon over the foam as a skin. Once the blank is cut down to meet the stringer, I can do what ever I want with the rest of the board (concave nose, belly, vee tail, etc.).
Second, I've been toying with the idea of making a carbon fiber stringer. The plan is to lay out a couple of layers of the tape with the approximate rocker I want, and after it's lamineted, clean that rocker/profile up. Then insert that into a blank.
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It does make a strong stringer, but it's a freakin' toxic mess to shape. I made a board a few years ago with "parabolic" CF rail stringers inset an inch or so from the outline. After shaping, everything in the shaping room was covered with a gray, itchy dust. Probably wouldn't be as bad if it's a center stringer, but if you do it, wear a tyvek full suit and use a really good respirator.
I did the carbon stringer thing too; and like surfthis says, it's a mess. Hell on planer blades also. I know some guys who build aircraft using almost all-carbon/vinylester, their shop is one big pile of gray dust and itchy people. A stronger is stringer isn't going to a whole lot for your structure anyway (unless you're building something that sends the loads there). Failures almost never initiate within the stringer itself, in anything resembling a conventional surfboard.
But back OT, it looks like the google ads at bottom of page are turning up some sources. Honolulu, you just have to shop it to find ''inexpensive'' carbon... But I can tell you that West Marine will be the last place to get a ''good price''.
I was hoping that by creating a pre-made stinger(s) with the correct profile, I could keep the cutting and sanding of the Carbon to a minimum. Then just bring the foam down to meet the stringer, and stop. I already do something similar with 6" wide sections of foam to make whatever width I want. I figured having 2 carbon stringers with a 6" section of foam on either side would be almost snap proof for the kind of waves I ride.
Howzit Honolulu, I got some from F.H. acouple of years ago for a decent price but they also told me it was hard to get because the military was buying it all, but you might try calling them to see if things have changed and they have some in stock. Aloha,Kokua
Hey Charlie, I forgot about FH. They have Carbon Fiber tape, but I don’t remember if it was cheaper to order off the internet. I’m pretty sure that the price I bought my 50" wide cloth was way better than trying to get it locally.
You may want to PM carvenalu. I saw Blaine during the summer and he was glassing paddle boards with carbon. He may have some good tips on laminating EPS with CF.
Okay, thanks to all for the tips. I'll rattle the cages and see what falls out.
I'm certainly onboard with the cautions not to sand this stuff, though I have the Tyvek suit and dual cartridge HEPA filtered respirator, AND would certainly do this outside and downwind from the family hacienda.
The blank is PU and removing the stringer via hotwire is only one way to go about it. I like the hotwire idea against the stringer for (possibly) making a clean, straight and perpendicular cut. Again, dilution is the solution to pollution: do it outside and downwind of where you live.
No expectation of replacing a stringer with a carbon version. A flat section of carbon would be inefficient - an "I-beam" or similar with flanges at top and bottom surface, and sufficient web to transfer shear, is what's needed there. Being and engineer, I have ideas in this regard, but the balance of labor in skin strength versus making such stringer beams, (taking into account the likelihood of completion) presently very much favors the staus quo.
A "rod saw" or rough bit of wire will accomplish the same thing, more slowly, as it abrades through the foam.
For the moment, anyway, this is all wizard wheeze. I gotta muster the motivation to take that blank in hand with disfiguring intentions. But no better chunk of foam to mess with in this manner than one which only cost 15 clams, eh?