I just had this idea this morning, but it was one of those light bulb moments that will get shot down in bright red and yellow flames, but here goes.
In the boat building world sika flex gets used for everything, on most boats sikaflex or some non foaming Polyurethane adhesive of a different name gets used for, sealing ad bedding in almost any sort of hard wear that gets installed. I used to work in a factory where we glued and bolted 3 ton keels on to 40’ yachts and the glue was sika flex.
When it cures it is still slightly rubbery and this is regarded as good because it absorbs shock and won’t shatter.
The other day I had a real #*ck up when I was installing FCS into some deep holes, as it started to exotherm it just cooked all the surrounding EPS. This got me thinking, I think some people use 5min epoxy to overcome this exotherm problem but the only 5 min epoxy I can get is thick and I know I will get lots of trapped air bubbles.
So my question is has anyone used sikaflex to install fin plugs or boxes?
I think it would be a good idea because:-
1- Its doesn’t exotherme
2-Wont reat with eps
3- Is tough as old boots
4- Is slightly flexable so will absord impacts and wont shatter
5- You can get it in black and white
6- Don’t think you would get many air bubbles when installing.
7- Sticks great to most surfaces- GRP and EPS, or PU foam there shouldn’t be any problems
The best way of installing it would be to manually work the stuff into all the gaps in the fin plug before filling the hole with the stuff as it doesnt flow like resin. Any deep fin cavitys would have to be pre filled so your not filling really large voids with the stuff.Those are about the only potental problems/instalation differences I can imagin.
Your biggest problem will be it’s flexiblilty. It likely won’t sand well. If you think it will sand, go for it.
Conversely, you can install those plugs in a two stage process: pour resin to fill to the bottom of the plug, let it set, then fill the plug all the way.
My thought would have less to do with the install than with the performance.
It could have an interesting feel… might be interesting to test…but here’s my thought
The boxes need to be stiff for a couple of reasons.
The main reason is that the base of your fins provide almost all the “drive”. If the base flexes, basically you would be creating a “stalling” effect as the flex would interupt the water flow and create turbulence. I can imagine it creating a “jittering” effect as it relates to the drive of the board.
Think of it like this…if you hold a sliver of paper and blow across it, it flaps loosly or has slow large vibrations. If you create tension on that same piece of paper, the vibrations shorten and the pitch gets higher. The more tension, the shorter the vibration and the higher the pitch and vice versa.
Now I know my example is in relation to “aerodynamics”, but in this case, this fluid dynamics principle applies to both “aero” and “hydro”
Applications will differ, but the principle still applies.
It might be a cool experiment though.
I wonder what would hppen if you coated the inside of the hole with the sika flex first and then installed the box as usual? Hmmmmmm…
I’ve done FCS with 5200…same shit as Sikaflex more or less. Works pretty good (thanks to Herb) but in bigger box systems , don’t do it. If there is any flex in the box or plug system there will be failure. What you are trying to accomplish in a fin system is a fin system that feels as close to glass-ons as possible, strong stable platform…So do you think putting fins boxes in with a flexible adhesive is the best thing?
Side bar, on the Probox’s I put in with 5200 i got a cool load up the fins and flex back feel to the surfboard. the problem was that the fin boxes were ripping out and failing because of the material used to set them…but they were fun for 20 surfs before the demise.
IF YOU DON’T CARE ABOUT ABOUT GLASSING OVER, LOOK AT PRO BOX…THEY TAKE FCS 2 TABS TOO!
SCREW THE PLUGS…SEE THE LIGHT! OTHERWISE GO BUY A CEMENT VIBRATOR FOR THE BUBBLES AND KEEP TORTURING YOURSELF. WHEN YOU STOP HITTING YOURSELF WITH THE HAMMER IT FEELS REAL GOOD!
Hey Thanks for the feed back guys.
So the gist of what your saying is, you need the bases to be as solid as possible. Yes this is probably the biggest problem with doing it this way, its the old performace vs longevity trade off, I guess you would never have a plug pull out with sika, but the flex you would inevitabley get is a big minus. The sanding issue is true too, it doesn’t sand that well, if you could slice it with a blade thats a dfferen’t story and a much better way of doing it but you have still got to make the plug flush.
I think that one way to get the best of both worlds might be to pour resin to the base of the plug so the plug sits on something firm then install the plug with sika, I don’t think you would get much fex that way. This stuff isn’t like silicon which is really flexy, when its fully cured is reasonably hard, also if there wasn’t much of a halo around the plug that would also help too.
But is it all worth it? I don’t know, its just an idea to bounce around.
Fusion is never going to be as strong as regular FCS because its not ancored to the deck.
I was installing the FCS Fusion boxes exclusively because I am a big fan of FCS as well
I recently switched to ProBox though so I can offer my clients the adjustability…and since ProBox also accepts FCS fins, it also increases the choice of fins I can offer.
Of course I will always give them FCS boxes if they want them…but if they can have all the fins, adjustability, a solid system and even MORE fin choices if they want them…it’s not a hard sell.
