You know, I like the way a wrap or two of glass around the center box keeps the box dead center in the rout and the boxes don’t try to float out the way they do if you set them with just milled fiber…
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Thanks. Sorry for my ignorance, I just need to get one thing clear: the way you’re describing it, it sounds like I only put hotcoat over the fiberglass patch, not laminating resin THEN a small hotcoat. Which is correct?
No worries dreaming, just assumed you knew all laminating of glass is always done with lam resin first…then hotcoat.
Merry Christmas!
I figured, but I just wanted to be safe. Like I said, first time.
Anyway, awesome advice. Thanks for the help.
Mark
Fins unlimited boxes are great. Much less fuss than other centre boxes.
You need to watch out for heating of the epoxy when filling around a center box. Prep the box like Kokua and Stingray advised, and put a fin in it. Level the tail area of the board on your stands. Mask to the edges of the routed slot. I use 5 min. epoxy to initially anchor the box for correct alignment; just about 1/8" in the cavity. Pick up the box by the fin, set, align. I fill around the box using 3 batches, and make sure that each prior filling is cold. After everything is filled and cured, sand the box down flush, mask the slot and laminate two overlapping pieces of 4 oz. over it (most the outer cloth is sanded away) about 2-3" all around the box. Fair the cloth in around the box and very carefully by hand around the slot. Hotcoat or glosscoat with the rest of the board. For side fins, it’s important to use a template to insure a tight fit for the boxes, which minimizes the amount of epoxy to set them and also the heating. I’ve replaced a few center boxes in EPS, and almost all had some degree of melted foam around them. The melted foam will create flexing areas which will leak around the box in time. The most reliable way to install center boxes is to graft a block of D-Cell or urethane foam into the blank first. This technique will allow the use of polyester resins to set the box using the methods that everyone described previously.
Thanks Pete. The board is PU, not Epoxy, anyway. Guess I never mentioned that.
Hey lokbox, I was reading over these instructions again, and there’s something that I can’t really place: You say that the patch goes after sanding/before gloss coat, but then you said after I hotcoat the patch, feather it in with 120 then gloss the patch — wouldn’t I be glossing the entire board at this point? The way I have it figured is, after setting the finbox in the slot and letting it cure:
• grind the lip and tabs off the fin box
• sand entire hotcoat
• tape off fin box cavity
• apply 6oz patch over fin box and laminate it
• hotcoat right away (5 or 10 minutes after lam)
• cut tape out of slot
• feather patch into rest of board (with 120 grit)
• i guess re-tape fin slot, then
• gloss coat entire board
let me know if this is wrong. thanks for all your help. sorry I won’t let this die 
Exactly. I thought you said you didn’t want to gloss the whole board, so I outlined how to do it with only glossing the cap over the box…
I had a thread last year with this writeup I was going to link to for you, but all the photos have turned to red-x so I figured I’d just put the whole thing new here for you.
backyard cheap and easy lokbox jig
~not endorsed by or affiliated with lokbox~
Took the photos after the process, but hopefully they still show well enough what to do.
Supplies needed:
Router (trim or regular)
Router inlay set
Loxbox box
Superglue
1/8" (or 1/4") masonite
spray adhesive
The most difficult part for me was figuring out how to mount the router inlay bushing on my trim router, as it wasn’t designed to accept one. This involved installing a chunk of masonite within the router base itself. Then, since the bushing stuck out farther than the depth of my jig, more masonite and some card stock was necessary on the outside of the base to get the guide depth just right.
Here is what a router inlay set looks like:
Here is one installed on my router:
The first thing I did was glue a lokbox box to a chunk of masonite using superglue. This one has already been sanded to shape, but the idea is that you’ll glue a bigger chunk of masonite to the box, then sand it back to perfectly match the outline. You can see the outline where it was superglued to the raised lip on the box.
Here is the first template, sanded to fit:
By the way, don’t do all this on a surfboard (duh). This one was used for demonstration purposes only.
Next thing, you’re going to remove the finished guide from the lokbox box. If you try to pry it off, it will probably splinter. I bounced mine of the floor a couple of times (box first), that seemed to pop it off cleanly. Left some residue on the resin dam of the box, but that will come off when it gets installed and sanded flush.
Then you take your guide, and glue it to another piece of masonite with more superglue:
Hard to see, but it’s there.
Then you take your router, and using the guide you just made as a template, very carefully trace around it. For this cut, you want the spacer ring (see it on corner of masonite) OFF of the inlay bushing. I started my router with the inlay bushing resting on top of the template, then slid it to the edge and dropped it down while keeping it against the template. I wound up notching the template a little, but better than than going outside of it and screwing up my jig cutout.
Again, don’t do this on a surfboard, use some scrap wood underneath.
Now you have your jig!
I kept mine in place using an idea I totally borrowed from probox. Simple spray adhesive (again, don’t spray it sitting on your board!):
Just let it get good and tacky before putting it down, and you might have to re-apply between boxes, but this is the cheap solution, right?
Now you put your spacer ring on your router bushing, get your jig set in place, and go to town!
If you did everything right, you should now have a perfectly-sized clean hole for your lokbox box. Practice on some scrap first.
On marking the locations, I did very careful measurements and marked everything out before laying down the jig for each cut. An explanation of just how to do that is far beyond the scope of this writeup.
If you think you might not be able to figure out how to mark your box positions and your jig to get consistent results, or if you think you might not be able to figure out how to get a good cutout for the deeper portion of the box, then this backyard method may not be for you. If like me however, you just want your box install to look clean, and don’t want to spend a big chunk of $$$ on the “official” jig (sorry JJR!), then this may be the way to go for you.
I assume no liability for any injuries or f-ed up boards that result from using this method. Oh, and you can make a jig for your center boxes using this exact same process. I did. One more thing, in response to my original thread (which I can not edit now, sadly), SuperFatPat added this info:
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Thanks Shwuz!
Since I don’t have an inlay kit, but do have a set of brass bushings and straight bits, had to modify it a little. Basically the same, but instead of taking the spacer on and off, I had to do math
Here’s what works out with bushings:
Tracing the guide which is the same size as your box: use a 1/4" bit in a 3/8" outer diameter bushing to make your template.
Using the template: use a 3/8" bit in a 1" outer diameter bushing to make the proper sized hole.
EDIT: easier set of #'s, using a 1/4" bit for everything:
Use 1/4" bit with 1/2" OD bushing
Use 1/4" bit with 1" OD bushing.
To anyone who wants to use these numbers: Please check this math yourself first!
Pat
…the very poor fin box installation kit is a driller with a hole saw…
-do a wooden jig the large of the box (only for the perimeter not the depth)
-put it on the bottom (in the place) and hold with tape
-cut the necessary holes with a steady hand
-finish the stringer with a sharp edge, etc
–do the glass like the others say
Great read and many helpfull suggestions to this newb. Hope Im not hijacking the thread but I am getting ready to cap a FU box that I just replaced in an old beatup boardworks epoxy board. I found a post/link on sways that discussed capping and they said to fill the box with flour and glass right over it. When done trim the hole right to the edge of the slot.
Here is the link ----> http://www.geocities.com/~kleb/windsurfn/buildboard/inserts.html
Anyone try the flour method or have better suggestions? Seems easier than taping and then you end up with a full cap all the way to the slot. However - I know tape will work - decisions, decisions.
Thanks for your help,
yoyo
Problem with that method is the glass ends up right at the edge of the slot. It’s possible to actually pull up the cap at the edge when removing the fin if not careful, or if any ragged edges exist on the fin. The industry standard is to tape off the slot with masking tape, then cut the tape back out after the hotcoat resin gells. Make sure to hotcoat directly after the lamination gells or within a few minutes…
BTW thanks Shwuz!!
Lokbox
Glad I asked – I didnt think of that problem but I can see where it may occur. Appreciate the help. Now to find the tape…
yoyo
Thanks for the help guys. One question—kind of a different subject, but still part of the process:
I’ve sanded my lap a bit, and there are some kind of white, milky looking areas from the sanding. Will these disappear with the hotcoat? Or will they show up? I’m not sure how to get rid of them.
Thanks
They should wet out with the resin…if not a quick wipe with a brush and some styrene does it.
i use a dremel and a straight edge.
I just mark where the box will go and work my way around. i found the router to block too much visually and just feel like i have more control with the dremel.
the box will float in the resin so i use a tile as a weight and a level. has worked well for me thus far. (about 5 boxes)
Thanks for all the earlier help — everything has worked out really well. I set the box, grinded down the lip, and have sanded the board now to 220.
So now I’m ready to do the patch over the fin box to reinforce it. As I was reading over the instructions on this thread, I had one question:
Earlier you said that after I laminate the 6oz patch over the fin box, to “make sure to hotcoat it right away within 5 or 10 minutes, then a few minutes after the hotcoat gells, you use a razor blade and cut the tape back out cleanly right on the edge of the tape”. So, to get this straight, do I pour my laminating resin on the patch, then let it cure for just 5 or 10 minutes, then hotcoat? Is that too quick to do the hotcaot? Should I just laminate it, let it cure enough to cut the tape, re-tape the slot after it cures, then hotcoat?
I’m afraid of laying over the hotcoat too soon and screwing it up.
Thanks
Quote:
Thanks for all the earlier help — everything has worked out really well. I set the box, grinded down the lip, and have sanded the board now to 220.
So now I’m ready to do the patch over the fin box to reinforce it. As I was reading over the instructions on this thread, I had one question:
Earlier you said that after I laminate the 6oz patch over the fin box, to “make sure to hotcoat it right away within 5 or 10 minutes, then a few minutes after the hotcoat gells, you use a razor blade and cut the tape back out cleanly right on the edge of the tape”. So, to get this straight, do I pour my laminating resin on the patch, then let it cure for just 5 or 10 minutes, then hotcoat? Is that too quick to do the hotcaot? Should I just laminate it, let it cure enough to cut the tape, re-tape the slot after it cures, then hotcoat?
I’m afraid of laying over the hotcoat too soon and screwing it up.
Thanks
I just hotcoat it around 10 or 15 minutes after gell. I said a few as an attempt to help avoid it getting too hard to cut.
But what you said here "Should I just laminate it, let it cure enough to cut the tape, re-tape the slot after it cures, then hotcoat? "
is the proper way to do it, this way the lam kicks off nice and hard before you apply the hotcoat "
Sounds good. Thanks Lokbox.