under-the-glass single fin boxes?

Not the O’fish’l ones

I saw them on Bill Stewarts boards. They look kind of like future boxs only they are 3/8th single fins boxes.

any one have any info, or know where to get em?

Hello, I work at Stewart. Bill designed that box for Future Fins. It’s called a “Strong Box”.  You can get the boxes from Future Fins. You’ll also need the router and jig setup to install 'em.



do you have a pic of them? Where can I see this boxes?




wow, they  look great! 


who is selling them in california or east coast?

Our shop gets them directly from Future Fins in Huntington Beach. You can try calling Foam EZ  or Fiberglass Hawaii to see if they carry 'em. You’re going to have to invest in the Routing/Jig setup in order to create the slot for them in the blank. 

The Future single box has extremely high ratings from the peanut gallery here at Coil Industries.


For the East Coast call Dave at Sea Level Surf (757-491-2711).  Its a pretty neat box but the router bit and jig is kinda pricey. 

Dave D

thanks for the info,

really sweet boxes.


fyi, as some one who typicaly does less than 5 boards a year, i cant justify spending lots of $$ on routers, bits, and templates for ever fin system. However,

I have become very inovative with a dremal tool, so no sweet on the install. :wink:

Ever tried putting regular single fin center boxes under the glass?

I have done several and they seem to do just as well as boxes made specifically for this purpose. I don't remember where I first heard or saw them done; may have been here on Sway's.

Just route the channel for the box before glassing, put a layer or two of some glass in the bottom ( I use some scrap 4 oz)  I then pour in enough resin to just cover the bottom approx 1/8" deep. I place the box in and weight or tape it down to keep it from floating. Let it set up, then finish pouring until the cavity is just barely to the level of the finished foam. After everything is set hard, tape on the foam around the box ( I use two layers 2" masking tape). Grind the box flush with the tape. Pull the tape, clean up your foam around the box with a sanding pad to get rid of any tape residue. Then tape just the slot with a good chemical resistent tape, give yourself approx 1/16 to 1/8 inch  of overlap around the open slot. Glass the board as normal. You can add a step and place an additional football patch first (I do this on the 10" boxes, I use fusions for the sidebites so what the hell, already have the extra step anyway). When you're done with hot coat, gloss coat, or spray (whatever your final finish is) Use your dremel to route out the depth and outline of the tape. I have one of those router attachments for mine which allows me to set the depth just right. You can use a straight edge taped to the bottom of the board to get it perfect.  Then just gently clean up the edge of the slot with a smalI piece of sandpaper wrapped around a stir stick. 

Last note: very important that everything be level and that the bottom of the channel for the box be even and cleaned out perfectly. When in doubt of this put a fin in the box and double check that everything is straight and tape it to hold until the box is fully set. Also when using with heavy pigments where you cannot see the tape edge; you have to just poke a hole where you are sure the slot is and then work your way around the slot with caution. If you have a dremel with the low speed option it helps.

I have used this combo (regular center box with fusion side bites) and it has been a very inexpensive way to set boxes under the glass in a 2+1 configuration. Especially since the fusion install kit is reasonably priced and couldn't be simpler to use. Like you I do about 5-7 boards per year and low costs and multi use is very important to me.

Hope you give it a try!

Poly resin doesn't penetrate 4 oz cloth over an open channel.

Keep it simple.

Thanks for the great advise! I started doing this with epoxy and it runs through like water. So a 4oz patch or bottom lam will eliminate the tape! Excellent!

We developed this in the sailboard era. Yes epoxy is too viscuous (thin). However, be sure to rough up the face of the box with 60 or 80 grit for a mechanical bond, and when opening the channel be sure to round the glass edge so there is no lip for a tight fitting fin to make contact with the layer or it can lift the layer off the box. The adhesion of poly resin/glass is only a mechanical bond.......

How do they go with tails that have a lot of curve?

I think most tail rockers would accept this process, the boxes have a lot of adaptability due to the built in "resin dam", if you used an extreme rocker on a very short board just use a shorter length box.  The shorter length will accommodate a more extreme curve.

thanks woody.

I usually glass in my box after the first lam, then sand it, tape it off, and put my patch over top. I’ve found that to be really strong.

I think a box like this should come out alot cleaner and faster cause you can just sand the top off just like some of the other systems out there.

The Stewart designed box has a flange which is susceptible to being compromised should you have a lot of rocker (like a noserider w/lots of flip) or contours like concave or vee…  Sanded flanges look like shit.

Dropping a Fins Unltd (aka Bahne) box in before glassing either results in a low (below surface) or is a nightmare to sand next to the soft foam. By dropping the Bahne box into the hotcoated board, you can quickly and easily sand to the bottom contour.

You can then take one or two layers of 4 oz and squeegee over the open channel w/o drips into the box. This is even quicker & easier these days thanks to UV resin. A lam and hotcoat over the box will take a total of 10 minutes or less if you know what you’re doing. You can even install extra support next to the box like the “woodies” we did on sailboards. We did some neat wood flanges too but they could be sanded to the contours before capping with glass…

Then just finish the board as usual leaving the routing open of the channel for last in case you are glossing and polishing a board.

When I first stated doing this in 1980-81, no one knew how we were doing it… guesses were that we made channel inserts, filled the boxes with water, etc… we kept them guessing.  

Recently I did a simmilar thing.

I rescued a badly damaged longboard from the beach trash can, complete with snapped nose and stripped bottem glass.

The boxes were still in place minus the glass, and they sat about 1/16th" out of the foam.

So instead of ripping the boxes out, I took my dremal with my carbide wheel and basically routed out a flange around the edge of the center box and FCS plugs. This made the edge of the boxes flush with the foam. Then I taped and re-glassed the bottom, glassing over the boxes. Then sanded off the top the box. (all after fixing the nose of coarse


Worked pretty good, and the boxes have held so far.

The Futures box comes in two versions, one dead straight and the other curved to “fit” rockered tails.