Following on from the board strength thread, I'm looking for opinions on what would be current best practice layup for an open ocean freeride board. It has to be strong and durable and flexible enough to soak up the bumps. Ultra light weight is not a driving factor so for a 100 litre board we might aim for the mid 7kg mark?

you really need to be around the 8kg mark for a strong board.

most light boards lack resin as a point of discussion.

layup i'd make sure it had a layer of hard core foam around the core with fibreglass inbetween, then more fibregalss then timber veneer top and bottom.

caron kevlar to all footpads, rails and mast track.

i'd also build bump pads into it.

I reckon firstly make sure blank is mega smooth so it takes less resin to fill pores (better adhesion with less resin etc)

From inside to out:

Bottom: 1 layer carbon tissue and resin with q-cell, 3mm divinycell, then 1 x 4oz

Top: rebate the blank from front of the mast track back, so you have double sandwich for about 2/3 of the board. Give that area 1 x carbon tissue and 3mm divinycell.
Then 2oz all over
Another layer of divinycell.
carbon patches for feet
2 x 4ox

That could be under 8kg and would be almost solid waveboard construction.

8kg would be acceptable weight in my book. Could that be done all up with straps and pads or without?
I've built a sailing boat before...

One of my slalom boards, James used Innegra (Polyproperlyene fibre cloth) to increase the boards strength and ability to absorb chop. Does wave boards with the same stuff

^^^ Innegra is the shazizzle but you can't sand it (like Kevlar)
so for "internal" use only unless u r really good
If you can get carbon/innegra weave in about 4oz it would be worth the trouble.

When I say 8kg I mean like manufacturers do - dry with pads but no straps or fin

If you haven't built a board before, you're probably not going to get the glass/resin ratios right the first time. My guess is it will turn out way heavier than you planned.
This is just my opinion, but if you have a go at making a board just use glass and don't get too techo with all the carbon, innegra and whatever else. That stuff isn't the easiest to work with and it's expensive so you probably won't end up with a great finished product.
Glass is the easiest thing to work with and it's cheap so probably your best bet for your first board. Maybe use some carbon patches for your foot reinforcements.
You'll make so many little mistakes as well as learn so much when you build your first board. The cool thing about it is you keep learning with each board you do.
Get into it and have fun!

If laying carbon on the bottom then laying it on the bias may make it a little more forgiving.

Instead of double sandwich on the rear deck would it not make more sense to use single sandwich with either a 7 mm divinycell or 2 x 3 mm layers and put all the glass on the inside and outside of that. If you use the same amount of glass and carbon you get the same overall stiffness but putting it outside the d'cell instead of in the (nominally) neutral axis will make a locally stiffer deck. Maybe the skin can be too stiff? Maybe the inner glass constrains surface dents?

In any case don't skimp on the fibre layers between the fin box and mast track.

If you make recesses for heel bumpers don't make them too big because it's only the flat part of the deck between the recesses that can carry deck tension.

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hoop said..
If you haven't built a board before, you're probably not going to get the glass/resin ratios right the first time. My guess is it will turn out way heavier than you planned.

This is just my opinion, but if you have a go at making a board just use glass and don't get too techo with all the carbon, innegra and whatever else.

Yes very true....


NotWal - try bend 7mm around compound curves..... :(

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Mark _australia said..

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NotWal - try bend 7mm around compound curves..... :(

Yes you can tell I have zero experience. I wasn't trying to pretend otherwise, hence the question marks.

So 2 layers of 3 mm? If there is no other functional reason to sandwich the glass between the d'cell then on the face of it it makes good sense to put it outside where it can carry local loads.

all of my proto boards were made from glass only. it is the way to go. it dents just by looking at it but it sails and it's water tight.

I'm not a fan of carbon as a means to reduce impacts. it just doesn't go the distance from my experience. it needs something else to take the hit. either wood or bamboo or Kevlar.

to be honest I don't like full carbon boards that much but that is merely a personal thing. I prefer the ride of timber veneer boards and they also have exceptional impact resistance.

the resin thing needs to be measured. you can work out weights of resin versus area, add material weight, paint weight, fixture weight etc. making sure everything is properly wetted out means using more resin.

some factories spray the resin on as that gives them better coverage and ideally keeps the weight down but clearly it doesn't work as intended with some boards as there are many examples of boards breaking due to lack of resin wet out.

you'll probably add weight when fixing your stuff ups up by bogging up areas. especially around folds and rails where it's hard to get the foam or timber to bend so you need to heat it, cut it, fold it prior to bagging, then come back with bog to get the finish smooth again before moving on.

things like finishing coats and painting can add 500g without any issue. that's one reason you see boards around with the patchy sanded finish. it's an easy way of keeping the weight down.

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NotWal said..

Mark _australia said..



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NotWal - try bend 7mm around compound curves..... :(

Yes you can tell I have zero experience. I wasn't trying to pretend otherwise, hence the question marks.

So 2 layers of 3 mm? If there is no other functional reason to sandwich the glass between the d'cell then on the face of it it makes good sense to put it outside where it can carry local loads.

and I am no engineer :)

have no idea why there is often a thin glass layer under d'cell. Obviously some thickener to fill all the pores for a better bond, but glass I dunno.
Maybe load spreading rather than adding to the effect of a sandwich being stronger?

there are multiple reasons.

putting layers of glass either side of the dcell gives the stiffness. the further apart the layers are the stiffer. adding multiple layer of glass and dcell provides more stiffness.

the density of the dcell and the weight of glass takes the impact. increasing density increases the impact strength.

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Mark _australia said..

NotWal said..

Mark _australia said..



...



NotWal - try bend 7mm around compound curves..... :(

Yes you can tell I have zero experience. I wasn't trying to pretend otherwise, hence the question marks.

So 2 layers of 3 mm? If there is no other functional reason to sandwich the glass between the d'cell then on the face of it it makes good sense to put it outside where it can carry local loads.

and I am no engineer :)

have no idea why there is often a thin glass layer under d'cell. Obviously some thickener to fill all the pores for a better bond, but glass I dunno.
Maybe load spreading rather than adding to the effect of a sandwich being stronger?

forgot to add. the layer of glass under the dcell is also to seal the core. you route out plug holes, box slots etc and glass the board prior to the layup and that seals the core.

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Gestalt said..

there are multiple reasons.

putting layers of glass either side of the dcell gives the stiffness. the further apart the layers are the stiffer. adding multiple layer of glass and dcell provides more stiffness.

the density of the dcell and the weight of glass takes the impact. increasing density increases the impact strength.

Yes but why put a layer of glass between 2 layers of d'cell when the skin would be stiffer with the same amount of material if you put all the glass either side of the d'cell?

the way I understand it to work is the combined stiffness would be higher than if you put the layers either side of the thicker dcell only because the intermediate layer increases stiffness by ensuring the layered components are stronger.

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kato said.. in another thread

I do lots of kms on my boards and a lot of the runs are in chop. Haven't even put in heal dints in the old boards. Not too many board makers are using 7mm divinycell all the way round. Just repaired a board that only had 3mm divinycell on the top and glass on the bottom, major damage on the bottom from a hit on the top.

Carbon Art gets my vote and you can always get James to add a little something to improve for your local conditions

I knew I'd seen 7 mm d'cell somewhere :)

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hoop said..

If you haven't built a board before, you're probably not going to get the glass/resin ratios right the first time. My guess is it will turn out way heavier than you planned.
This is just my opinion, but if you have a go at making a board just use glass and don't get too techo with all the carbon, innegra and whatever else. That stuff isn't the easiest to work with and it's expensive so you probably won't end up with a great finished product.
Glass is the easiest thing to work with and it's cheap so probably your best bet for your first board. Maybe use some carbon patches for your foot reinforcements.
You'll make so many little mistakes as well as learn so much when you build your first board. The cool thing about it is you keep learning with each board you do.
Get into it and have fun!

Great advice.
In my favour I used to lay up trailer yachts in moulds in the 80s, and have built a wooden stitch and tape boat from plans. I think i could give it a good shake. I'd do some experimental panels first too.

ian

I can put you in touch with people that will make your life easier both in sourcing materials and also getting blanks cut.

if you don't mind modelling your boards in a computer, there is a guy on the sunny coast who has a 3d shaping machine. this is by far the best way to go and allows small changes to be made. he also has the ability to scan boards. say for example you had a shape that you thought worked very well.

there is also another guy that might even let you build your board in his factory.

if you're starting from scratch it's best to spit out the foam blanks, glass them up and sail them to see what they are like. then tweak the design and go again. it usually take 2-3 version to get a really solid shape happening. rocker and volume distribution for example will make or break a board.

As a guide for you for an average size wave board, for each 4oz layer of glass (2.3m long) I mix about 180ml of resin not all of this is used I pull some out with the sqeegee and some is left on the plastic it is wet out on. I know of other people who use a lot less to get 5.5kg boards but they dont seem to last.
Bottom over eps
1 layer 4oz
6mm pvc
2 layers 4oz
Deck over pvc
1 layer 4oz
Carbon heel patches 6oz
4 or 5mm pvc
2 layers 4oz
1 layer 4oz from mast track back
4 layers carbon 6oz over heel gybe area
1 layer carbon patch around mast track.
= 6.3 kg wave board before straps pads and fins.

whatever they use

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choco said..

whatever they use

?rel=0

Bouke went berserk on his boards :D

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choco said..

whatever they use

?rel=0

How will they stay in business with no repeat customers???

Recently snapped a witchcraft at Corros from a hard landing.When I removed the paint in prep for repairs it became clear why it snapped.Whoever glassed the board stopped the carbon in a straight line right on the rail extending towards the middle of the board just in front of the foots traps.Doesn't matter how exotic the materials are if bad practice is employed in the construction you will end up breaking what is otherwise a great board.Its good to get and use the advice before adding the hardener and for those who should know better like the board builder who made this particular Witchcraft don't get slack.Spoke to a guy who said he was a team rider for Witchcraft and he indicated mine is a production model and the best boards are the customs, maybe that's the way to go.

it's true anything will break.

as a general comment I wouldn't get caught up with the dyneema thing. starboard and other manufacturers have used it in the past.

all of my boards I get made with Kevlar around the feet area, rails, fin boxes and mast track and that stuff is almost the same as dyneema. just heavier. I specifically ask for it but still I'm not about to take a hammer to them.

I was pretty surprised to read your post rider. do you use a stringer or something to provide some strength? any boards I've had in the past like the layup you describe have done either of 2 things which are developed delam or been creased when landing flat.

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R1DER said..

As a guide for you for an average size wave board, for each 4oz layer of glass (2.3m long) I mix about 180ml of resin not all of this is used I pull some out with the sqeegee and some is left on the plastic it is wet out on. I know of other people who use a lot less to get 5.5kg boards but they dont seem to last.
Bottom over eps
1 layer 4oz
6mm pvc
2 layers 4oz
Deck over pvc
1 layer 4oz
Carbon heel patches 6oz
4 or 5mm pvc
2 layers 4oz
1 layer 4oz from mast track back
4 layers carbon 6oz over heel gybe area
1 layer carbon patch around mast track.
= 6.3 kg wave board before straps pads and fins.

Not quite sure how you figure the lay up has anything to do with de lam. Sounds more like they haven't been built properly if that's the case.
Riders lay up sounds pretty solid to me.
I don't think you need to over complicate it too much.
A well built board to Rider's specs would be pretty solid I reckon. He's built a fair few. Pretty sure he knows what he's talking about.
Consistency and neatness in your building process counts for a whole lot.

Oh, and by the way. When was the last time someone attacked your board with a hammer, or pulled the fibres out of it and tied them in knots?
Do some proper testing I say!

the layup definitely has a role in delam. other than water damage or resin issue or eps issues, delam can happen because the layup can't take the impact of heels and feet. surely you know that. what happens when someone starts tacking boards with only pvc and glass in the layup. or grabs a catapult and lets the nose cop the full force of the mast. how about landing a flat jump. like you've pointed out you guys have built a few boards in your time. we all have and we've all walked different paths it seems.

i'm not denying that riders layup works for him but I'm a little more cautious because there is effectively 3 layers of glass stopping the board from breaking in 2 so I'm real surprised he's found that to work. I would have figured if it did all of the board manufacturers would be making boards like that.

the other thing that jumped out at me is i've also seen many boards experience issues when the carbon is stopped mid span. in the early 90's when carbon first started getting used boards were breaking regularly and the theories floating around were because glass and carbon had different inherent flex characteristics but I'm now certain it's just about transferring loads to an area that can't take the force

again no disrespect to you or riders skills here, I've seen what your design is capable of and it's impressive but should we not actually talk about these issues because the thread title is about best practice layup.

No, sorry you're wrong.
If the lay up isn't strong enough you will get soft spots or breakages with use. De lams are caused by bad glassing.

so a soft spot is not a delam. ok then.

No, a soft spot is not necessarily a de lam. It can be where the glass has failed or the foam has failed. A de lam is where the glass separates from the foam ( usually caused by bad glassing techniques)
I guess my point is that if you build a board well using a good glass lay up like Riders, it will end up being lighter and stronger than a board built badly with all the techo stuff.