Really sad that I had to end a great session today, after a nasty wipeout in some fairly heavy surf. My assumption was the leash was wrapped around the fin and when the leash got yanked tight, thats what did the damage. Fin is gone, and the box is broken in several spots, and the resin around it buckled up and sucked some water in 
its a 10 in. single fin box, and I was wondering if this was something I could repair myself or if I would be better off taking it in to the repair shop. I have looked into the ways to do it and the 2 that came up were routing out the old box (which seems like the better option) or cutting the sides out of the old box and trying to pull it out. Which with a 10in. single box I feel would remove a lot of foam to be desired. Any advice would be great, for now its sitting by the heater getting blasted.
Clear, detailed photos of the damage would help in assessing the situation.
Sorry I probably should have done that to start off with. Here is a few. The one from the side is showing the buckled part
Hi -
Yes, that box is toast. Fortunately not much glass lifted around it. Assuming you do not have a router or jig for that box, Iâd say your best (and easiest) method of repair would be to take a Dremel tool with reinforced composite cutting blade and carefully go all the way around the flange so you can separate the glass from the top of the box. If no Dremel, a sharp utility knife will do the job but take multiple cuts and perhaps tape down a metal ruler or something to protect the board around the flange. Please do not let the utility knife slip and cut in to surrounding area.
Once the top glass has been cut away it shouldnât be too difficult to pry the box straight up and out. It definitely looks to have separated so use another fin as a pry bar or a screwdriver or what have you⌠a little back and forth might help if it seems really stuck. Maybe cut deeply around the flange with your utility knife. Donât worry too much about little chunks of foam coming out with the box. Clean any obvious loose debris in the hole and mask off the board around your opening. Hopefully you will be left with a hole with fairly clean edges.
Buy yourself a new fin and a new box with the flange. Scuff the outer box and prepare to install that baby. Level the board so the box area is on the horizontal. Mix up some resin, thickener and catalyst⌠maybe a bit of white pigment. Pour in the resin paste youâve mixed up and insert fin box with fin inserted and masking tape placed around the fin and box slot. Smooth off any excess with your gloved finger. Make sure your fin is vertically oriented and tape the fin tip down to each rail to keep it straight. Let set.
Peel up all your masking tape and scuff all around the box. Make sure the slot is masked and laminate a few layers of glass over the top and extended past the edge on to the bottom of the board. I use sanding resin for this step. When cured, grind off any excess
resin/glass.
A top coat should be applied next⌠I usually mask off the bottom about 4"-6" around the box and make sure the slot is masked off as well. Brush on a layer of sanding or finish resin and let set. Pull tape before it gels too hard. A bit of elbow grease and some fine sanding should have it ready to go but you can take it several steps farther for a nice shine. Just use finer grits of sandpaper followed by some rubbing compound. If you donât have a buffer, just skip this step.
I am assuming that you donât have a router, bit and jig for this method which is admittedly a âdown and dirtyâ method. Best of luck on this if you decide to proceed in this direction.
John, Thank you for the very in depth reply. I think I want to go that route and fix it myself, partially because I am broke, and partially because I like to fix things myself. The more I can learn to do, the better in the long run. I Actually do have a router and bit that I picked up for installing FCS2 plugs on previous boards I made ( I have shaped 2 surfboards so far thanks to advice and tips picked up of sway before I decided to join.) I donât however own a jig for the single box, but it might be worth making a home made one if the router job would be easier. As far as dremeling it and prying it out, after I get the box out, would I need to sand down the gloss/hot coat on the surrounding area of the box before I lay up a couple layers of glass on the new box so it lays flush? or would I be cutting the glass to fit just a couple mm outside new box? The current set up has a hole drilled all the way through for the leash, any additional steps needed for that? I am thinking drilling a hole in the new box where it lines up with the hole, taping the deck of the board where the leash hole is and another piece on the box where the hole is drilled so when I fill it with resin it doesnt leak into the box.
I currently only have epoxy resin will this work ok? No additive F for the sanding resin but if need be I can pick some up. From my experience with this epoxy on the last surfboard I made, I used no additives for the sanding coat and it seemed to sand just fine after curing for 2 days with the heater cranked up.
Thanks John.
Remember that when you route out the box, do it in two different deapths, cause I think that is a future single fin box. The first route should only be a few millimeters down, this will be where the whole outline of the box. Then the middle section should be around an inch down, and you will want to route this part a little bit at a time with the deapths of those boxes if you try to do too much you could burn things.
Oh and yes you can use epoxy, and you have to make sure to prep sand all spots that you want resin to stick to
Nice avatar repairman! Thatâd be an opah and a bluefin right? Down in SoCal if I were to guess. I know I am supposed to sand the surface before coating, I was more referring to if I should get the surrounding glass sanded down so when I lay up a few layers over the box it will be flush. Or if I was only supposed to do a patch of glass about the same size as the box and only lightly sand the surrounding area for a mechanical adhesion. I think I am going to go with the dremel and pry method, as I dont trust my router enough to grind out the existing plastic.
http://www.swaylocks.com/forums/router-bit-and-stringer-elimination
-homemade router jig and HD foam insert for a Bahne channel
http://www.swaylocks.com/forums/q-bout-replacing-fin-box
-more John Mellor, a Harbour video with a full-on vacuum router jig, and Bruce Jones (RIP) mini-stringers
Thanks J, it seems like iâm getting some of the best advice from some of the best on here! Ivâe been following lots of stringâs threads as well as Kokua who has yet to show up, due to the at home garage methods. Which your fin box design seems to hit the nail right on the head. I have not heard much on the foam inserts, would that be used if I accidentally rip up some foam and egg out the existing hole too much? I would still like some clarifications on what to do about the leash hole and how to tackle that issue. I think for now, im going to get started on this project and attempt to rip the box today so I can properly dry it for a new instillation early next week. Hoping to have this done in time for a 3 day trip starting next saturday. If itâs not bothersome, I think im going to post step pictures in my process for both my own sake of keeping tabs for the future, as well as trying to contribute to someone who may have a similar problem and can have a thread to reference.
If you have shaped a couple of boards then this is your chance to step it up and use the router. Get a new sharp top bearing bit and go in increments, not whole hog. If your router allows, use the 1/2" shank bits. You have been given very good detailed info on the process. This is now a used board and the perfect opportunity to advance some skills. Mike âWildogâ Williams (Kokua) sadly has passed on from cancer. Still have trouble saying that.
Oh man⌠I am very sorry to hear that. I do not know him personally but from what Iâve read he was highly regarded around here. Shared a lot of helpful information, that will live on to the test of time. I guess that is a harsh way of realizing we should really take every precaution possible when working with the materials we do.
I ended up using the dremel to take it out and enjoyed the work, and am fairly pleased with the outcome. Yes, I followed johnâs post almost to the T to get the box out, along with a few other things I had read.
From the pictures below, I started out by cleaning the surrounding area with a small amount of acetone on a shop towel. I like to start things out clean to ease the process. I taped around the box first to help prevent any scuffing from the dremel, as well as the metal ruler john suggested.
Taped the ruler down and proceeded to dremel away the straights and free handed the end curves using one hand as a guide and holder to reduces shaking from the dremel hand.
After I had a clean cut all the way around I used a box knife to slice the last little bit before lightly prying to free the chunks off. I switched dremel bits and smoothed the jagged edge.
I drilled several pilot holes on the lip of the box around its parameter and screwed some 3 1/2 inch screws that were slightly larger than the holes making sure they were 3-4 threads deep. This allowed me to use some plyers and slowly pull, wiggle, and pry the screws on different areas of the box before finally pulling it loose.
Sadly as you can see there was a fair bit of foam that came out with it so I will need to fill that with something before placing the new box.
Not in the pictures because I canât capture a good one, the flange of glass/resin around the box has been separated from the foam from when the box broke and buckled like in the first post of pictures I had. I am thinking of trying to fill that with a small amount of resin and clamping it down to make a flush flange around the outside of the box before installing the new one. Any thoughts on this, or maybe a better idea? Thanks again for all the help.
Well that is a real bummer, I did not here about mikes passing.
And for the leash hole just tape it off before you install the next box. Then when the resin is cured you just re drill through the box and the old leash hole
Nice job using the screws for some pulling leverage.
I think I would Use some ~3/8 inch strips of cedar, or perhaps something more dense, along the sides of the New box, rather than worrying about the missing foam.
Looks like a traditional longboard shape so any weight gain should be of little concern.
I dislike the holes through the back of the box for the leash loop string, as one loses 1/4 inch of fin adjustment range for the knot, but it seems a cleaner and stronger solution than a leash cup.
Hi - Congrats on getting that thing out. Donât worry about the ragged flange area inside the hole. Just mask off the board close to the edge of the hole and use pigmented thickened resin to install the new box. Put a piece of tape over the leash hole before pouring the resin in or it will run out the hole. Scuff the bottom several inches around the box before laminating a few layers over it. I wouldnât bother with any mini-stringers or foam inserts with the flanged box. I think youâre gonna be stoked once the new box is in place. As long as the edges of the flange are a fairly good fit to the foam, the rough stuff underneath wonât be noticeable.
Is that jagged, lumpy foam going to inhibit the piece of cloth UNDER the box when I am setting the box? I am picking up my new box today and the fin is coming in the mail. Thanks a ton for the help through the process. I am already stoked on getting this thing fixed, learning a new tool to add to the belt and saving a couple bones by not taking it into the repair shop!
I wouldnât worry too much about glass under the box. Those boxes with the flange and some glass over the top seem pretty secure. Placing some glass under the box probably wouldnât hurt anything but with all the jagged edges and broken foam, you will be getting a pretty good mechanical âgripâ with the resin. Iâve always added glass under the box but in retrospect? Not really sure now that it did all that much good. The box and any surrounding resin/glass just form a big solid block. If you hit something hard enough, the whole block gets jammed in to the surrounding foam. In my opinion the same thing holds true for the Chinook boxes unless theyâre the type that has the riser that goes through to the deck. The ones with only the ridges along the sides just form the same sort of block as the regular box and will jam in to the surrounding foam the same way. What seems to be key is to have some kind of structural support other than light foam surrounding the box. Glass over the top, stringers on each side, high density inserts, or little âstar burstâ mini stringers inserted perpendicularly to the box edges seem to work best in my experience.
bump
Sammy, thanks for keeping the right threads continuing. Those damn Asian postâs are somewhat irritating. Turns out, futures are great with fast shipping. Ended up getting the box into town today, and picking it up tomorrow. will lay the box in tomorrow, glass and hot coat on friday and if im lucky I can surf it on sunday or monday but I am not crossing any fingers.
Too bust working to be posting. Finally caught a break. I finished setting the box. Had to route out an extra 2 inches because Futures no longer makes the 10inch 2 piece box so I had to get the 12 solid one piece, which isnât a bad thing. I donât have the jig so I got some free hand router practice which ended up turning it very good for no jig! I traced the box with a dry erase marker for the flange to be routed, and measured the lip for it to rest on so I could estimate how much to take out for the deep part of the box. Let the box set than pulled tape, glassed over it and waiting to hot coat around midnight (photos are of setting the box, no glass photos. Will upload a final set of photos for the finished product. ) And I know the pictures are crooked, but that fin is lined up as perfect as the naked eye can get it.
