There plenty out there for info on PU but not for very specific for EPS.
Laminate.
Cut out box hole 1/16 bigger than box with a router and jig.
Then what?
Lay in some cloth and resin?
Just resin?
Resin and cut up fiber?
This is for #2 EPS. Does it need cloth for strentgh?
After just melting out a couple fcs plugs the other day, I really need this to go smoothly or I’m gonna loose it.
Thanks
just drill the hole tight…to minimize the amount of excess resin that can pool up under and around the box and exotherm.
cloth is optional, but it certainly can’t hurt.
and if strength is a concern, cap the box with a little more glass when you’re done.
The fcs rep recently set me up with a high density foam for installing the plugs. Its a bit more work, but he said it eliminates any heat issues and adds 25%-30% more strength. Try giving him a call.
If you give Fiberglass Hawaii a call they have a super fast setting epoxy that you use with their fast set hardener. It mixes 2-1 and goes from a liquid state to hard in 1-2 minutes depending on the temperature. It kicks so fast that you can only do one Futures box at time. The reaction happens so quickly that it never has time to get hot enough to melt the EPS.
It’s what they recommend to install boxes in EPS. I’ve never used the FCS plugs but I’m sure that they can give you tips. The beauty of using it for the Futures is that you can glass the board immediately after installing the boxes.
Thanks for the up. Although I’ve done a good balance of futures, fcs and rtm glass ons, I’ve been dropping futures due to tail weight and rigidity, you really notice it when the fins are in the board, it shifts the center of gravity back a few inches. Seems the firewire tail flex hype is trickling down and a few of my accounts have started ordering much more fcs. I know the tails have been heavier using futures, especially with quads, but I didn’t put much thought on the topic of flex. I’ve been using mostly resin reseach… it’s been a while since I glassed with their aluzene epoxy, I remember it was pretty good though. I’ll drop in there for a refresher, thanks.
Install future boxes before you lam. Make sure you have cooling temps or you’ll outgass around the box where the foam is unsealed inside the hole.
No need for cloth in the hole, but a small 4 oz patch over the box will add strength with minimal added weight. Just cut the hole to fit the box, scratch it up with some 50 grit and clean it with denatured alcohol. Then seal up the slit with tape nice and tight, mix up some resin with the slow hardener if you have it, put some resin in the hole, and insert the box, making sure the resin squeezes up evenly around the box. Wipe off any excess.
When you go to lam, seal the slit up again with tape really well and cut it with a razor blade as soon as you can handle the board.
Thanks everyone.
But when I said FU I meant Fins Unlimited Fin box. Guess I thought it but didn’t type that…
Anyway, Installing a find box into EPS. Before or after lam?
What’s the best tool for sanding down boxes?
Thanks.
Rick.
I like to install Fins Unlimited boxes after I lam, then I grind down the box to the lam with an orbital sander, being really careful not to burn through the lam. Then I put a patch over the box, fair it out when it’s cured, and hot coat the whole deal.
Cut the whole just to fit. Make sure (1) there are no air bubbles under or around the box. It’s gotta bond evenly and fully with the foam on all surfaces. And (2) be sure to put a fin in the box when you do your install so you can measure the cant accurately. You’d be suprised how many people forget to put the fin in until the box is already set in the hole… what a mess. Tape it up so resin dosen’t get in the slit.
In my previous post, I was referring to a Fins Unlimited box. It should be installed after lam.
Thanks everyone.
NJ_surfer,
When do you pour in resin? Before putting in the box or after putting in the box?
After lam. 2 layers of cloth underneath, 2 oz of resin & hardener (total). Pour in the mixed resin, hold the glass around the box, stuff it into the hole, put a fin in (or a pair of 3/8" thick pieces of wood - with 2 you can sight along them and make certain everything’s perfectly straight) and tape it down.
I like to take the lip off the box with a grinder & a grit wheel. The 14000 rpm grinders for metal work go SO fast that you don’t have any melting/smearing epoxy issues. If you take it down with a sander/polisher, keeping the disc in the same place too long can remelt the epoxy a little & you can get some clarity problems. Totally minor, but also avoidable by using the grinder. The grinder’s grit wheel also doesn’t flex at all, so your touch will be very accurate. Just be careful - at 14000 rpm, a tiny dig can make a big hole.
Tape the box & do your hotcoat & you’re all set.
be sure to put a fin in the box when you do your install so you can measure the cant accurately. You’d be suprised how many people forget to put the fin in until the box is already set in the hole… what a mess.
Why not just line up the FU box perfectly with the stringer? Why do you need to have the fin in to tell if the box is straight? Is a little cab-o-sil or milled fiber a good idea? Thanks!
We’re talking about the cant angle…
Resin in the hole first… I like to place the box in the hole with the trailing edge (back of the fin box) first, so the natural properties of any bubbles under the box is to rise toward the rocker apex. This way, you’re pushing any bubbles “up” the rocker. Rather than fighting their inclination to rise, you’re pushing them uphill, which is the way they want to go.
If you have any room for resin around the box after it’s set, top it off right up to the lip of the box, so a miniscus forms. You might want to get a piece of thin wire and poke around the box to puncture any bubbles and let the resin flow into any voids.
We're talking about the cant angle...
oh yeah…that WAS a stupid question.
Thanks.
sure… you could put some filler in there… and some pigment, too if you tinted or painted.
I prefer not to use cabosil in epoxy… just me. I find it’s harder to emulsify completely. Others will disagree. I think the best thing to do around fin boxes is a combination of microspheres and milled fiber.