"Could you please explain how this would be possible since Lokbox appears that it was be at least as heavy as Futures if not slightly heavier because of the thicker flange and larger metal pieces. "
I’ll chime in. The future boxes are nearly 6 inches long. The Lokbox box is 5 and 5/8ths long. But more important would be the cavity length(deeper cut). The weight comes mostly from the resin, as a mass of resin compared to the same mass of plastic has the resin being MUCH heavier. Since Lokbox has a much shorter cavity less resin is used. But as mentioned the Lokbox flange is thicker and there’s the metal plate and screw to consider. All in all probably a wash or very close to it meaning the two systems(installed) are really close in weight. The fins are irrelevant as most fin companies have lightweight honeycomb core fins (maybe not Pro-box not sure). Of course you can’t compare a board with solid glass fins to a board with honeycomb fins. Obviously. As far as weight of fins goes, I cannot give you specs on everyones fins just the ones I’ve weighed. FCS’s G-AM stock plastic fin weighs 78 grams. Our stock plastic Al Merrick template weighs almost exactly the same. Our handmade solid glass Al Merrick template weighs…are you ready?..74 grams. How is this possible you say? Simple - A molded plastic fin has to have an increased foil thickness to remain ridgid. Not a problem with fiberglass. Ever seen G-10 fins? Used mostly for tow boards. Why? Streamlined, low drag, anti-cavitational foils…without suffering loss of rigidity. So, a solid glass fin is actually lighter? Absolutley. Why are RTM honeycomb fins even lighter? Mold is injected with resin then pressurized. This extracts ALL excess resin much like vaccuum bagging a surfboard. It’s all about the resin boys. Do it clean…comes out light. Do it sloppy and you got excess tail weight. There’s a reason a laminator uses a squeegee instead of a brush…
Systems using an oversized rout such as FCS, speedfins or pro-box have a large concentration of resin around the plugs/boxes. This creates a few problems. It makes it very difficult to control overheating as well as shrinkage of the resin. Polyester resin does around 50 % of it’s shrinking in the first 24 hours after catalyzation. As it shrinks it only has one way to go, and thats away from the plastic. No mechanical bond there like resin interlocking into the pores of the foam. Ever seen a salt ring around an FCS plug? That’s water between the plug, and the white resin ring that’s evaporating back out. You can sometimes run your fingernail across where the white resin meets the plug and you feel an edge. That’s the resin pulled away from the plastic. Now, as water works it’s way in around the plug (it does) everytime you bottom turn or whatever that plug is moving back and forth within it’s casing (the white resin). Since water doesn’t compress(you know the rule of physics for every action is an equal and opposite reaction) the white resin ring begins to weaken. Since the weak link is the white resin not the actual plug or box, what happens is hairline cracks form in the white resin allowing even more water in compounding the problem. At some point you do a bottom turn and whole thing just rips out. Most popular explanation for this failure? Bad install. Well, this may only be partly true. Fin installers at shops have to get x amount of boards done each day. They don’t have time to set resin off super slow and wait around all day to rack the boards and bring more down onto the floor racks. So they speed stuff up. They have no choice. This isn’t speculation it’s fact. Knowing that, the tighter the rout the less likely a fin guy will fry your install. Ever seen yellow rings around FCS plugs on the deck side?
Large accumulations of poly resin harden more brittle than small accumulations, due to compounding acceleration rates of the resin transforming from a liquid into a solid. Mix a half full bucket of resin and catalize it like a hotcoat. Pour a small amount into a dixie cup and set them both on the ground side by side. Tell me which one goes off first, and which one turns yellow, starts cracking and smoking. The larger amount guranteed. Not trying to dis on Pro-box because I really think it is a well thought out system, and it caters to experimentation which I think is key to progressing this sport forward. So I say good Job Pro-box!! But you do not want water getting in ANYWHERE, or eventually you will most likely have problems. Shops that do way less volume have stronger installs. Imagine that.
When Lokbox first came out it was like a giant FCS plug and it was installed the same way with the same chopped glass/white pigment/lam resin mix. We had some boards coming back with broken boxes. Upon inspection we quickly realized that the box wasn’t breaking…it was the white resin around the box that was letting go. Bill Bahne and I did a test. We mixed up a batch of lam resin with the FCS power that they provide for their install. Mixed it with no white pigment, thoroughly, and let it sit for 24 hours. Next day we opened the jar and mixed it again to make sure we had complete saturation. All the stuff had settled to the bottom so we know we waited long enough. We then put a couple of drops onto a slide and stuck it under a microscope. what we found was microscopic bubbles clinging to the 1/64th " length fibers, all the way around the fibers themselves. Bill Told me “those are spheres…where cracks can originate. Best install you could ever have is a tight rout…with straight lam resin, and no white pigment (titanium oxide also weakens resin)and capped with fiberglass”. I listened, and redesigned the box to be capped over with glass with a very tight rout. Our problem went away overnite.
Laminators use a squeegee instead of a brush to remove excess resin for a stronger board. A floated lam will result in a board that will ding and break easier. Not sure why people don’t apply this same logic to fin systems. There’s no difference.
