I am talking about what to use to adhere the box to the eps core. I have seen it done both ways. I like the idea of gorilla glue (or pour foam) because it fills voids and is lighter (especially if the gaps are big). However, Alex Aguera, Seatex (I think?), and others are using epoxy with a thickener.
I think that as long as the box is firmly secured, foam might be less prone to error and voids.
thoughts?

I would definitely install into a hard foam , not straight into the eps. Unless the box is already surrounded by at least a cm of hard foam. I'd use thickened resin . About as thick as mayonnaise. Butter the sides of the box and board hole , then pour too much thickened resin into the hole . Push the box in and let the resin overflow up the sides . There shouldn't be any voids left . Some people like to make a tight fit between hole and box , I like to leave a slight gap ,( half to 1 mm each side , no more ), so the resin flows up the sides of the box and to give a bit of sideways adjustment . Put an old fin in the box , tape over where the fin goes into the box so no resin glues the fin in. Check with a square edge that the fin is in straight. The board will have V , so check there is the same gap on each side of the fin and the top of the square .
If your installing twin tracks you don't need to be too accurate , but you do need to get the distance between boxes right .

Thanks, Imax. I should have clarified that what I will install is the twin tracks surrounded by divynicell.

Too easy , jobs almost done . I'd use thickened resin . Anything that expands may lift the box .

Agreed not glue. I think that came from surfing it's nowhere near sufficient for WS

Layer of glass around the whole cassette with epoxy/qcel and some milled fibre doesn't hurt.

As much glass over top as you can

And slowwww resin cool day falling temp so no expansion.

Why use just one when you can use both? My router skills are quite poor, so I ended up using both epoxy and pour foam a couple of times when installing tracks. First, glue the box in with thickened epoxy. But if the fit is not great, you might end up using an aweful lot of epoxy this way, so I have used pour foam for fill any remaining gaps. I don't think using pour foam right away would be a good idea, though, since it could be hard to keep it from lifting the box when it expands.

^^^ That reminds me too its not easy to router accurately
draw a line with fat texta (sharpie for the Yanks ) so its like 2mm wide line (1/16") and cut up to it and leave the line on - well thats what you'd do if you were doing woodwork. Then its too tight - so for our install we want to take half that 2mm wide line away with the router. Then its easy to have a little gap all the way around that is just enough.

Remember the corners of the hole will be rounded due to a round bit in the router, so round off the corners of whatever you're installing first...... otherwise you cut a hole way too big all the way around and regret it when you realise why (been there)

Need to make a jig like this


Just nail it to the deck and perfect sized holes

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Mark _australia said..
And slowwww resin cool day falling temp so no expansion.

Yes, yes and yes.

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elmo said..
Need to make a jig like this

Just nail it to the deck and perfect sized holes

Hah! I can tell you quite a few ways to still mess up with a jig like this . But then, I used a router for the first time in my life when installing foil tracks. It's gotten a bit better after the first couple.

I like to use an oscillating tool to cut boxes. Far less kerf and mess.
I use the semi-circle blade and a builders square to get it perpendicular.

Gorilla glue works best when under pressure while it cures, the more pressure, the better the bond. It does soften over time some so not great for stressed areas or long term.

If you are installing the tracks into the divinycel dont do a straight edge at the front, sets up a sheer point, do a V shape.

I'll buy that same "cassette" but I have some divinycell so I could make a sheer point, I guess.
How many layers of glass on the bottom? 3 6oz? More?

Our latest project we reinforced a wooden cassette foil box with two 30" stringers. There is a weight savings from a full deck to bottom hard foam block but it is a little more work. We are hoping to spread the load over a larger area. If it fails we will update.

Update:

cutting the whole with the router was pretty easy. I used west system 209 "extra slow hardener". I am glad I went with that one and not the 206 "slow hardener" because it got a little bit warm (the 206 might have been fine but I didn't want to test my luck).

This is making me think that when I eventually repair my foilx I should do this and swap out the tuttle with mast tracks

Did you put glass under the box?

Nope

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WillyWind said..
Update:

cutting the whole with the router was pretty easy. I used west system 209 "extra slow hardener". I am glad I went with that one and not the 206 "slow hardener" because it got a little bit warm (the 206 might have been fine but I didn't want to test my luck).

I used 206 and melted loads of EPS

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WillyWind said..
Update:

cutting the whole with the router was pretty easy. I used west system 209 "extra slow hardener". I am glad I went with that one and not the 206 "slow hardener" because it got a little bit warm (the 206 might have been fine but I didn't want to test my luck).

I used 206 and melted loads of EPS. What volume did you use. I think I used 150-200cc reckoning that averaged to a 1mm layer.

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Manuel7 said..
Did you put glass under the box?

I did one and put some down the sides, but inserting box dragged some down and wonder if it creates a wedge and void. didn't put any at bottom as had to router three slots all the way to deck to add extra HD foam slabs for rigidity.

I put waaaaay to much resin in the bottom . Wiggle the box down and there will be no voids . Use super slow resin with milled fibres to mayonnaise thickness.
Ps , mask off a big area , cos the overflow.
pps , I use Surfset Flex for this kind of stuff , hardly any heat and sets like plastic not glass brittle.

Just repairing yet another foil board with loose tracks install due to gorilla glue / expanding PU stuff.
Its crap.
As I said its important to router the hole accurately - which means taking the corners off the block so you don't make the hole too big to fit square block in a hole with rounded corners (router bit is a cylinder yeah )
Then that hole that's too big means too much resin.

Right consistency epoxy/Q mix will flow up the sides as you push it in and placing it correctly means it will not drag off the block during insertion.

Stringers won't save you if its an insufficient lam over soft 11-15kg EPS either. Anyone who has peeled a couple of layers of glass off a biard by hand will know how easy it is to delaminate it

No more tips as I put quite some time into figuring out unbreakable

I installed the box. I used thickened epoxy an As Imax said, the excess of the bottom squirted out of the sides. I mixed probably 350 cc but a lot was left in the mixing bowl.
it was not a hard job but I was a little bit nervous. the board is made out of some type of plastic like the starboard tufskin so I used west system G Flex instead of regular epoxy to lay the layers of glass and carbon. Sanded the area with 80 grit, wiped with isopropyl alcohol, and flame treated.

Oh, as mark said, next time I would routed with even less clearance on the sides.

I find an oscillating tool even better than a router. Tighter lines and you can get the corners square. Less mess as well.

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WillyWind said..
Nope

Somehow reminds me of my cousin 20 years ago who bought internet received the modem plugged it into the computer and then called me complaining she is still offline.. so I asked if she tried to plug the modem into the phone jack on the wall. which she didn't ... lol

Please don't use gorilla glue.

Before you laminate the layers of carbon / glass over the top , sand the paint and bog off the surrounding area . First layer a bit bigger than the box , next layer a inch wider all round , same again and so on . 4 to 6 layers . I'd do 6 cos I'm a box head . I'd hand lam in two goes with a sand in between. You could do 4 layers in one go.