Step 1 is to buy a 50mm sheet of eps and cut my shape. 5'8 by 22 - shape my rails and slightly take a little thickness out of the nose and a fraction out of the tail on the bottom.
2 inchs is pretty thin but i will be taking no foam out of it excluding a slight taper at nose and front - trying to cut doen on mess and just make a cruisy quad - i have a thing for wide boards - makes jumping frfom noserider to shorty's do-able.
Step 2 I will then laminate the bottom with two 6oz layers with out laps and then place wax paper over the laminate.
Step 3 place board wax papar down onto a table with the desired rocker profile and weight board accordingly.
Step 4 once laminate is dry take board out of the 'press' and continue to glass as per normal. "rocker should be set (I hope)"....
Last board i did in EPS did 3 layers of 6 on top and 3 on bottom and it was light and strong and went great time for the second experiment. This board will be stringerless so I will be heavy on the glass again.
I love the bouyancy and flex of the eps - this method of creating rocker should work similar to vacc bagging methods? or will the memory in the EPS be to great and it flex back - my original thought was to pre bend it in the 'press' before lamintating but i imagine it wont hold?
It problably would… but It would hold much better if you bought 1 x 25mm sheet (4’ x 8’ is what they come in over here) cut it in half and glued them together with the rocker you want with GG. Shape it then just glass as you want. When you glass I’d put a little support under nose and tail to maintain the rocker.
Have fun, take pictures and let us know how it turns out!
Just getting ready to start this little side project.
In between my two sheets of 25mm if I laminate a layer of 6 oz cloth with epoxy will this help with overall strength in the board and still keep flex that comes with eps? It will definetly be a good way to hold my rocker.
And secondly will this be a better option to strenthen the tail area for setting FCS plugs. I have had a few problems with plugs pulling out in another eps quad construction I have built.
I just use PU Gorilla Glue to put my 25mm pieces together and hold the rocker, it works just fine. the Glass/epoxy will make it heavier and more expensive.
Find some PU foam, maybe an old beat up surfboard totear apart. Use the foam as inserts where you'll be placing the fins. Glue the heavier foam in with the GG.
Hi Bee, I dont think its the number of layers that create the rigidity but its a by product of many layers that creates strength and thats the curve of the deck laminate.
Ive been working on making the thinnest XPS board, its a 6 layer compsand vacced with 4oz /6oz/ innegra / veneer / 10mm XPS / 4oz.
Its 13mm thick and Im cutting the ends off the FCS plugs so they dont stick out of the deck.
Layers are stronger than a single core but only by virtue of the glass in between the layers.
Thicker is stronger than thinner but not exponentially so.
From the test boards Ive done, the greater the curve of the external glass, and the greatest curve is seen on the deck, the stronger the board, way beyond a flat deck..
So if youre worried that a 2 layer board isnt going to hold the rocker, Id suggest doming the deck as much as possible or give the board a Vee bottom so both sides of the board are like convex shells facing each other.
In total the board will be three layers, Im adding an adittional 25mm sheet ontop as I want to add a concave deck. Im riding a concave decked fish at the moment and love the feel. Basically the top sheet will be in two pieces almost like wide rail bands slightly bevelled back to meet the two layers of 50mm in the middle, say 8 inches from the midline on either side (toatal width will be 21"). Just trying to hide a little bit more volume. Bottom will be a slight concave through to a vee in the tail.
Thinking i will glue up with a epoxy ( Purely as i have spare) - but seal layers to keep good bond between layers and not loose resin into the eps, or or would a PVA glue be adequote?
Last EPS i used a glassing shedule of 3x6oz on top and 2x6oz on bottom so whatever rocker I loose from the glue up i will rest in the final laminate.
Top layer at its thickest part will be around the 1/2 inch mark. so around 2 1/2 at the boards mid. The rail bands or concave will be kept to the middle third of the board just to get that little extra volume. Tail thickness will be some where around the 1 1/2 and nose tip at around 1 inch. want to keep as much meat in the sandwich so to speak.
Will steer cleer of the resin glue up idea and glass heavy and spackle pre-laminate, this will help hide the join of the two rail bands onto the deck.
Do everything the same for the blank, but just use a glass tape, maybe a 3" wide tape, along the rails.
Then you can weight the blank down before you glass it to get the rocker you want. Just rig up something that will allow you to glass the rails while the blank is pressed into the desired rocker. You could even put a small edge by taping off a cut lap line then do a tiny bit of sanding to bring the exposed foam down. Then re-tape it for a clean edge and the lap should be at or slightly below the foam. You can then do a regular lamination over the rail and the blank should hold it’s shape. This will give you a strong board, maybe too stiff for you, but I like stiffer boards.
You won’t have to worry about touching the wet glass.
I have a 2" thick EPS with balsa over it. Rides geat.
definetly lots of options - shark country looked at your idea when i was toying with the idea of using carbon fibre rails to mimic the fibre flex boards, but after researching on here the vibe was that it looks pretty but doesnt really offer that much difference to fibreglass shedule????
My biggest concern is that if I leave the board with out the rail bands and concaved deck (3rd layer ) that the 2 inch thickness may be a fraction to thin for me at a weight of fluctuating 90kg. (180lb or so). Board will be 5'10 .21. 2.
Anyway thursday is the day to get inot the knitty gritty so i will see how it all pains aout.
I keep the thickness all the way out to the rail on my 2" boards. But, they are 7’2" and 8’, so your’s would be thin.
I didn’t mean Carbon Fiber, but regular fiberglass tape. Carbon Fiber might be hard to wrap around the rail without bagging.
I would be concerned about the board holding the rocker without having the glass wrap around the rail. I’ve had boards go flat on me more than once. I always get the rails as solid as I can as soon as the rocker is set to hold the rocker shape. Usually this is done by adding wood rails.
I have done concave decks from flat foam with the vacuum bag. The foam will follow any shape you use as the rocker bed. Then once the rocker is set and is soild, you can reshape the bottom to be flat or whatever you want. We’ll do that with 1" and 2" sheets of flat EPS using epoxy resin and thin wood between the 2 sheets. You need a rocker table or something to create the rocker. We often use other boards. Just leave the foam the same thickness all the way from nose to tail and stick it to the bottom of a board you like. Once the glue up is solid you can profile it and finish it. Don’t let it sit because the rocker will flatten out.
The other option is to glue in a wood stringer and set the rocker that way. We like to put the wood in the rails with light foam, but I’ve been cutting out rocker slices from 6" thick slabs of 2lb EPS and gluing them up to get the width I want. Then I shape them with a planer and other shaping tools.
A little from column A and a little from column B seems to be the approach.....
The thinking behind putting a layer of 6oz in between my sheets was more to do with strength than rocker. It is a sacrifice in weight but im hoping it is an improvement in strength that offsets the weight addition. Think about this - How many Firewire or for that matter Bonga Perkins Perkins Mals do you see snapped? Around my part of the world you see heaps! No core support, just a whole lot EPS.
Would a layer of 6oz improve my core strength dramatically or do i need to look towards d'cell, but being not proficient with vaccumming.
All boards potentially can snap but a strong board that lasts a while is never a bad thing.
Think about this - How many Firewire or for that matter Bonga Perkins Perkins Mals do you see snapped? Around my part of the world you see heaps! No core support, just a whole lot EPS.
...All boards potentially can snap but a strong board that lasts a while is never a bad thing.
Have shaped a EPS 5'8 (ish) * 22 * 2 double flyer. Was going to keep the bottom flat but i have gone with a single shallow concave into a slight vee in the tail. I have kept a fair amout of meat in the tail ( 1 1/2 inch) and nose but a little concerned that the concave has taken away from my already minimal thickness (after thought). At 90kgs will this float me still? Or should i look at ways to add some volume - had a play with adding some voplume to the deck with EPS cut offs but gennerally was unimpressed.
Will do a super heavy glassing shedule probably 18 oz decka and 12 bottom.
HELP.
Just concerned i have blown the thickness and float of the board.
