the last board you made blew me away and i have a feeling this will too
Ok. I corrected all my mistakes and I produced a quality section. I am very impressed with the results. Check it out!!
very cool, maybe you could cut some fins out of that? Slightly curved ones…
looking forward to the next step!
I’m loving it!
I’ve never bult a hollow board before, but have envisioned the process many times and it seems simple enough. That is simple enough to make a mold… I’ve heard the hardest part was making the bottom/top seam stronge enough to not seperate while surfing.
The thing that has always dettered me is, I can’t imagine it being THAT easy. Not when companies like Aviso have limited models (becasue they are expensive to make)
You might want to send Airframe ( Ken from segway composite) a pm he makes the hollow cf/hc board. Just wanted you to beware of what could be a potentially devastating problem.
Wish you all the luck bro, jsut wanted to give you a little heads up.
A little PS.
I would hope after Berts post alot of shapers wouldn’t be so threatened with surftech. This is not NASA engineering, these are mostly methods anybody with a little time and a little moeny can do in their garage.
I dare you to blow a blank in that mould…add a little concrete to both halfs and your in the blank buisness…Sorry i wish somone would try that I did …whole new respect for any blank manufacturer!
As you are probably aware, the PVA will not give you quite as good a finish as just using a good mould release wax, (Meguiar’s #8 or #16) but PVA is still a great release material. One area you may run into problems is with the divinycell. Even after you let the epoxy cure (and I suggest you post cure the epoxy up to at least 130 degrees) the divinycell will still dent. I use aluminum honeycomb in order to minimize the denting. The tooling looks good, but you may want to go with a vinylester tooling gel, so it can be buffed and polished which will also help in the release of the finished part. Epoxy face coats are strong and good for many releases, but the finish tends not to quite as good. Are you pulling a full 30 inches of Hg? You can put a gel coat in the tool first, let it cure, than cone back with your epoxy laminate, so when you pull your part, the finish is complete.
Sounds like you are doing a great job!!! Keep up the work!!! Have fun!
Ken
Why worrying about the exterior texture of the shell??
I always thought that all of those AVISO and other hollow carbon sandwich boards were standard glassed (4oz) once the 2 halfs were joined, just to ensure that bottom and deck won’t dettach.
At least, I think a 4oz. glass rail band would be necessary for ensuring both waterproof and joint.
Something like this:
The way I did the KOLSTOF board rail bonding way by way of a lap joint, which is having the top and bottom of the two halfs overlap. There is internal support via extra cloth tapes on the rail to give support, but no external cloth as in a normal lay-up. The Hydro Epic boards are done the same way. I think the Aviso boards are done with an internal blatter and their rail construction may be done in a different manner. I have not seen a cross section of one of their boards.
Ken
The Alvisos are done with an internal bladder, and they don’t have a seam. This makes the process much more simple, eliminates seam issues, and gives you a finished product right out of the mold, but it makes it impossible to add internal bits to control strength and flex. Seams will always be an issue. As long as the parts fit, and they’re glued correctly, everything will work peachy. Any voids or improperly glued areas along the seams have the potential to become fatal problems. Of the thirty or so Hydro Epics I’ve broken, 90% started with seam failure.
Glassing the outside of the seam will tie the parts together but it kind of goes against the idea of using female molds. The beauty of molded parts is they come out finished - no grinding, sanding, or polishing - and the same each time (and true to the original).
Anyone with time and money can make hollow molded surfboards - but it’s not “a little time” and “a little money”. At Hydro Epic we spent over a year and a million bucks making crappy (but great looking) boards before we had a product that I was comfortable selling for astronomical prices. It is WAY easier to make boards from foam and glass.
This may also be a good time to point out that Ken’s partner Michael Halun made the first Hydro Epic boards before moving on to Kolstof, and made Confederate carbon fiber motorcycles before that. Michael is a true craftsman.
What a great thread! Thank you lpcdefg for gettng your project going and on Swaylock. Kendall and Airframe chiming in ice the cake.
Quote:
I always thought that all of those AVISO and other hollow carbon sandwich boards were standard glassed (4oz) once the 2 halfs were joined, just to ensure that bottom and deck won’t dettach.
Here’s an old sketch I made showing how Hydro Epics went together. The jog that the kevlar takes at the rail was achieved with an additional element on the mold. It would leave a recessed lip that the bottom edge could wrap around and glue to. The top has the extra flap - instead of the bottom - for a couple reasons. The extra kevlar added some crutial strength, and because kevlar is a bitch to sand - this method kept the kevlar edge from being exposed. There are a couple ways to achieve the same results, but this is how we did it. Fit and finish is CRITICAL. You must use a gluing jig - could be the mold - to get it right.
This was in the dinosaur days when we still used a stringer that attached the top and bottom halves. Newer boards don’t use a stringer like this… the decks and bottoms are reinforced with a super-secret rib/torsion box system that gives better strength and more controled flex.
[code]
Kendall,
What I meant by little time and little money is mainly jsut composite boards in general, didn’t mean to undermine any of your hardwork or the amounts of money you had spent building you’re boards. I just wanted other builders to realize that theses “new” technologies aren’t out of grasp for anyone. Even when I was typing that response I didn’t really want to say that… Mainly I jsut wanted to encourage people. The point is you don’t have to spend millions to make yourself and some freinds some really great boards using different techniques then the standard foam/fiberglass.
Wow…
I don’t know how I managed to overlook this thread so far, but I’m really glad I opened it just now. That is some really impressive, really ambitious work for a home-builder. I am seriously interested to hear how it works, the test panels look great! Can’t wait to hear how you handle the rail-seam problem.
Seriously great stuff!
I don’t feel undermined at all. My skin isn’t that thin… I was just trying to point out that the road to perfecting new technologies can get long. We may have spent way too much time and money getting the formula right… and “right” is a subjective term. I just know from making hollow boards how many things go against making them work. But… I don’t want to discourage anyone from trying new stuff.
I think the closing of Clark has been about the best thing that could have happened to surfboard design. At least people’s mind’s have opened to other possibilities. I love that boards are coming in different flavors… finally.
I think lpcdefg is doing a hell of a job. Still though… making PU/PE boards is really easy.
Foam and glass is easy but there is adventure in experimenting.
Hi lpcdefg -
Thanks for showing us how you do it. I feel very fortunate to be getting an inside glimpse of the mold making process and your composite techniques.
Having input from Kendall and Airframe is icing.
I’m looking forward to updates and the finished product!
I made the bottom half of the test section. Then I glued the top and bottom halves together to make a full cross section. I am going to experiment with different internal stiffeners until I can make the test section strong enough for my satisfaction. I plan on anylizing the performance of the cross section at the mechanical lab at my college.
Here is the completed cross section
I am starting the next test section with additional improvements.