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 Building Dagger Board Cases, Clam Shell Style...
After a lot of head scratching and asking around, I believe I have come up with a combination of techniques that combined make this otherwise painful job a smooth construction. One piece, finished and painted when you are ready to install. This is assuming you have your boards first of course. Mine were to final shape though I hadn't bothered to fair the ends and paint. Good enough for this.
   I first wrapped my board with black builders plastic and fastened with packing tape. This is just to protect the board. I cut a 9mm strip of ply and taped it along the trailing edge to keep the case length I wanted. Then I got a piece of used carpet of desired thickness and wrapped it around as snug as I could, cut to length at the strip of ply on the trailing edge, and taped in place. On my first case I then covered the lot in black plastic but found it wrinkled a bit from the warmth of the epoxy so on this one I wrapped the whole thing in packing tape, two directions. Took some time and a couple rolls of tape but I found it worthwhile.
   A different view of the taping process.
   With the tape in place that epoxy doesn't stick to, and a light cote of PSA (release fluid) if you like, I lay on my glass (450 or 600 db is fine). The side nearest this view is the trailing edge. The glass is purposely left hanging over this edge. Explain later....
   This is the view of the leading edge and you want just enough glass to get around the corner but not more than that. I have just started to wet the glass in this photo, you can see the far end starting to wet to the surface. If you are careful at this point, the join to the glass on theother side is seemless. Use the just enough resin to wet the glass to the edge and no more.

 Here I have wet the glass all around . The trailing edge needs resin for the first inch or two and excess wetting there is inconsequential. Just drips on the ground.

Not visible in this photo but I did put a little strip of peel ply on the leading edge.

I have also begun wetting the glass with a glue mix (cab-0-sil) in preparation for applying the foam sides. I have also wetted the back side of the foam with the same mix and then....


 Lay my pre cut foam in place. You want enough glue mix to be sure of getting the air out. I used the cut foam but in retrospect, I think plain foam would have been just as good, maybe better. I used 15mm 80 KG stuff and I think plain 15 or 12 mm foam of 60 KG would have sufficed and maybe been easier to handle.


The foam comes within a couple inches (50-60mm) of the trailing edge and about 4 or 6 inches (100-150mm) from the leading edge.

   I used some light ply and timber with weights and clamps to hold the foam down and squeeze out air. It would be hard to use too much glue mix but easy to use too little. You can always wipe off excess.

 Did I mention this is one of those projects you do along with other stuff? It's an hour here and an hour there and time to let set in between.

Anyway, after letting the lamination and foam gluing set overnight, I fill the crevices with resin, first a little thinned pure resin (5% acetone) to get it into the wee bits then a slurry of resin mixed with cab-o-sil and Q-cell. I use a rubber to work it in as best I can. And working wet on wet....


 I immediately go from filling to laminating over the foam and covering with peel ply.

let set.....


 This is what I have the next morning. I flipped the board over and carefully remove the peel ply from the leading edge. Important... you don't want the fresh laminate to break away from the edge. If you do you will have a little more fairing work to do later, don't panic but try to avoid disturbing it.

Now use your packing tape and maybe a strip of black plastic too, to provide a mask against the trailing edge laminate from the previous step. You don't want resin to go down the slot between that previous work and the form. Seal the groove all along the length. But be tidy. You are going to be laminating over the top of that work. The idea here is that when it comes time to pull the board out, these parts WON'T be attached and the case can spread apart due to flexibility remaining in the leading edge.

   So now you begin the process like the other side. This time you will be laminating over the leading edge of the other half so they will be joined at this stage.
   Laminate wetted and notice the peel ply over the leading edge.
   Foam applied as before....
   And here it is done again, wet on wet with peel ply over the edge and foam panel (cheek) ... let set.
   Next day you should find it easy to left a side up a little. PSA mould release liquid helps but the packing tape surface itself should be enough to guarantee release.
   So, slip your board out after carefully prying off each side and put a stick in there to see what you have. This surface would have been good enough as is but since I could .... I did..

 I gave the surface a quick sand and spread some filler mix with phenolic microballons.

In this state the sides, or cheeks where the foam is, is quite stiff with the flex all in the area around the leading edge.

The most forward part of the leading edge flexes less as it is a double thickness of the laminate which is where you want it.

Something to remember working the case is that the resin doesn't really harden for several days so don't leave the unsupported case in awkward positions for too long. I flip it over now and then or hang it from a bar or stick it back in the board.


 Sand the skim coat of filler off (if you used any) and paint. Here is two coats of epoxy primer and a coat of polyurethane ending about the waterline.


While this work was being done I cut some scrap foam to fill the small gap between the end of the foam sheet and the trailing edge. I got both sides glued in amongst it all.


 As soon as the paint is set, back on the board and clamp snug. If the laminate got a little out of shape from being green and awkward, this will probably fix her up.


Here I have stripped off the peel ply on the edge and cut back the peel ply on the cheek panel of foam. In this photo I was just about to lay on a heavy tape (750 tri ax) over the leading edge. That will give the leading edge a double layer of the case laminate and the 750 so at least 1650 gram all up. The leading and trailing edges are where the mass needs to be.


 Here I have gone through my scrap pile of foam and cut odds and sodds and wacked them on with glue mix.

You can see the 750 tri ax protruding out the end under the foam.


 Sand to fair soon as you can...

notice I've stripped away some of the peel ply near the top of the foam and I also stripped some of it away when I glued on the foam strips by the trailing edge.

   And tape over. I used about 4 layers staggered.

 And apply Q-cell mix as soon as it gets firm. Let set. When it goes this time the shape is done. There will still be enough flex to get it off your board but only just.



 Here is a fine tuning opportunity. You can flex the trailing edge enough to adjust to taste.

Overall, I wanted plenty of room. I've seen sailors going through hell with over tight cases. Stuff that! If it sloppier than I want later. A glued in piece of carpet will fix it up but if you get it too tight..... yer screwed dude!

   Here I have the shape I want and have used some scrap ply strips and screwed them though both sides of the trailing edge parts.
   Here I have the thing tipped up so the side of the trailing edge that isn't attached is on the downhill side. Notice the funky collection of scrap foam pieces by the trailing edge.. we'll get that soon.
   I couldn't do this and photograph it too... but what i did was mix up a loose batch of glue mix and gently poured it (thin stream) down the part of the trailing edge that wasn't (yet) attached until it started showing at the bottom. Then I laid it down on the trailing edge, slightly canted toward the glued side.
   That is what it looked like after. Works for me!
   Now I can trim off that excess dangling bit and shape the trailing edge and the scrap bits of foam.
   I used A LOT of glass on the edge (about 3000gram) and a good deal of filler over the bottom layer to get good shape and provide a composite of sorts. This was all done wet on wet of course. I let it go just firm and applied Q-cell bog. Sanded at first opportunity, stripped off the rest of the peel ply and gave the rest of it a coat of filler and sanded back. Result is below.

 A lot of little steps but all manageable. I got exactly the shape I wanted with a very good finish. And I didn't need to hire a circus act to juggle two halves and taping them together.


PS... you could park a truck on those things.. tough as...

And acknowledgments... leaving the trailing edge dangling to extract the board and glue later was an idea from Mal Salisbury. Applying the foam cheek panels to stiffen that area and leaving the leading edge flexible was from Bob Burgess. These two renown builders have been invaluable sources of advise and information and I am just digesting, combining the best of the ideas in my opinion, putting my two cents in and delivering it to you.


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