Select to expand quoteGestalt said...
yeah i know the weights he uses.
I use dumbbells
Select to expand quoteikw777 said..
This manufacturer doesn't put glass between eps and PVC. At least I couldn't find any. 
If they have to write "from tail" on the track measurements, well.......
Personally I use Riders layup but I hold my tongue to the side and bite it a little, and always wear two pairs of gloves. I discard one pair of gloves when they are laden with resin and some of those pesky fibres so I reckon I save a good 500g there.
Select to expand quoteb]Gestalt said..[/b]
yeah i know the weights he uses.
Oopsey im calling you out on this one! Push the chips over to me for this hand
Your very quick to share your board making knowledge/ideas and quick to critique other experienced board makers. Yet you are unable to answer on the spot how your own boards are constructed which to me indicates your real expertise. 
The banter has been fun but i think id better just stay in the WA section
Select to expand quotehoop said..
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!
I sail with a "Hamma" all the time so I know what I'm talking about
, current board construction is crap regardless of who builds them "old technology"
what's your thoughts on new technology choco?
I've got a slalom board in the works and I'd considered pricing it up with dyneema but would entertain other more innovative solutions.
last year some newish products came out combining innegra/carbon/glass into the cloth.
basalt fibre is also pretty new.
one thing that interested me is improving the bond between the laminates by using certain fabrics.
I've got an idea of the layup for my next board but I'm yet to get it priced.
Adding some fuel to the fire... the next 'making of a board' vid from CA has just gone up www.carbonartwindsurf.com/factory-talk-windsurf-board-sandwich-construction/
Comments on a postcard please
burn baby burn
so what's your preferred layup for "Best Practice Board Layup for Strength" mcsmurfin, I'm not sure anyone has defined use but seems waves have been mentioned so I guess we need a board strong enough for big air and reefs.
A 100 litre board strong enough to handle 2000km per year at Redcliffe for five years or indefinitely.
i don't understand how ribs are more of an advantage over foam. they both do the same thing which is to support the layup and stop twist.
AirInside have been making honeycomb core boards for yonks. I seem to recall the honeycomb is Nomex.
Select to expand quoteGestalt said...
i don't understand how ribs are more of an advantage over foam. they both do the same thing which is to support the layup and stop twist.
So the kit can be posted.
Except we don't see Salomon surfboards around any more ;) On the face of it hollow seems like a good idea but if you spring a leak you can literally sink. Nomex is good stuff but expensive and not the most user friendly.
Wouldn't dare to proclaim a 'one layup to rule them all' but at the end of it when you're out there sailing the materials you put in need to be decent and how you put them together can make almost a bigger difference as other have said. If you're laminating is too dry it ain't gonna work, if it's far too wet the extra resin adds weight and can also be weaker (floating fibers aren't strong). Are your fibers running in one direction or multiple? Are your load areas reinforced? Are they being reinforced without adding 'hard points' that just introduce a perfect breaking point? Strength with flex or strength with stiffness? Finishing without sandthroughs is another area to get skilled up on too. The kind of sailing and sailor also makes a difference of course - some windsurfers are just absolute gorillas technique wise and no matter what you do they'll keep flat landing smashing away as hard as they can till something goes
Select to expand quote
The densities quoted for airloy 0.01 to 0.9 g/cc work out to 10 to 900 kg/cm.
Rider said he uses 14 kg/cm EPS so there doesn't appear to be much weight advantage to airloy.
EPS has a nice amount of elasticity and it's easy to work. It's faults seem to be it's porosity and poor structural integrity.
Maybe airloy can do better. It appears to be worth a closer look.
There is a lot of talk about sandwitch layups on the leading manufacturer's web sites. However, the fragility of most boards under 'normal usage' conditions tell a different story. If these boards are built as per their specification, I doubt we will be having this discussion.
Another point that I would like to contend is the 'myth' about boards being '"cheap" and built to a price. A board may appear cheap but compared to an air conditioner (much cheaper than a board) or other similarly priced items manufactured in Asia, they most certainly are expensive.
A final point which should be remembered is that most boards manufactured in Asia cost a mere fraction of the RRP to manufacture.
14kg foam is the norm. board makers tend to use sealers on their blanks. probably also a major reason for boards delaminating. there seems to be some views that if you can finish the shaping smoothly enough you might be better to go without the qcell and use a cerex layer or just not get upset about weight and laminate a layer of glass direct to the foam.
if you use sealer I think thought needs to go into how it's handled, how much to sand off and what temps to apply it. if the layer between the foam the the laminate breaks down your board is stuffed.
funny thing is you will never really hear shapers talk about the specifics of what they use unless you are standing in the factory with them or helping them. it's their ip after all so they aren't generally too keen to give away resin mixes, shaping tricks or specific layup details.
I wonder what bouke uses? he seems to like h glass so I wonder if he uses a sealer based on hollow glass
Gestalt can you name 5 known windsurf manufacturers and their boards specifically which you believe has an eps cord that has been sealed and sanded before laminating? I reckon I have worked on pretty much every brand of windsurf board coming into Australia and I can say that the common feature in pretty much all of them is to penetrate the core with resin .
Watch the CA vid - no bulshizer there - about as clean and simple as it gets.
What you have described is some surfboard and sup construction methods completely foreign to windsurf construction and therefore somewhat misleading to those less informed, and not a fair representation of the board producers as a whole..
So which brands and their products can you put forward?
yes I agree it was somewhat of a blanket statement. and yes the q-cell and sand method is more of a custom approach.
but I think (and tell me I'm wrong here) that board manufacturers are putting fillers/foaming agents etc into the first resin coat specifically prior to bagging so it seals and bonds in one go.
fair enough if I have that wrong.
My take on it is this.
On the use of fillers, this is primarily to act as a thixatropic agent - a thickener if you like - which prevents the resin from wicking away into the core foam and so a degree into the cells of the divcell, which results in a dry lamination. The light glass(with the exception of heavy reinforcing in wave boards)layer between core and pvc has a primary and secondary role but I do't want to split hairs as opinions do differ. My opinions are formed by consultation with great board builders, my own controlled testing and also analysis of many board constructions through my day to day handling of damaged boards. Firstly the glass is there to control the amount of resin/glue between the core and the pvc. I have used from 25gsm continuous fibre cloth to 150gsm. My findings apart from the difference in weight, was that impact resistance was not significantly increased by increasing the weight of the glass ply. The most significant finding was that using a tight and flat weave(trying to really optimise the resin/glass ratio) the glass behaved almost like a peel-ply. In a nutshell what is needed is a relatively open weave. I use 68gsm(2oz roughly) plain weave there. I also use nano-fibres in the resin. Bagging pressure is pretty critical and environmental conditions are also a factor I consider particularly with resin viscosity, absorption rate and gel times. For example if I add 2% nano-fibres I need to know those fibres are going to remain suspended in any resin migrating into the blank and therefore optimising the cross-linking across all structural components. If you really want to go hardcore I suggest filling the pvc cells with a lightweight filler and nano-fibre filleting compound but the lamination needs to be wet on wet, so you are going to be going like the clappers to assemble it within your gel times. Same on the outer skin but you can let that cure and then clean up the board before glassing.
There is lots of 'talk' of board builders sealing the foam and cleaning up before laminating - this is usually done by surfboard builders and those sup builders who have emerged or taken advice out of the surf industry. Some of the fillers being used are gyprock skimming products believe it or not and there are a host of other products being used - however I don't have time to research methods that are that low-tech. Not a good practice in my opinion is all. In a nutshell these guys are trying to seal the blank to reduce resin absorption to save weight, control the resin/fibre ratio, and to make the blank a little stiffer to work on - a surfboard blank out of 14kg foam is impossibly flexible.
So if we can leave that behind as an inappropriate tech for windsurf, and move onto foaming epoxies and adding foaming agents to resins - primarily in the layer between core and PVC as this really is the only layer where we can use it unless using a -/+ pressurised mould.
At this point you need to think about what I have said above about the resin migration and the formation of a structural system which extends surprisingly deeply into the foam core. Using a foaming agent promotes this, though it introduces a whole new set of issues and the degree and rate of foaming needs to be optimised to the core foam. Again vac pressures and environmental controls are significant.
Is this innovation? I don't think so - Its just building on the legacy of great board builders of our time.
Core foam is the achilles heel.
In the mean time I'll continue to try and find an engineered solution to a hollow board with a cross-linked internal structural matrix. 3D printing with recycled drink containers springs to mind..
Select to expand quoteMan0verBoard said..
...................Core foam is the achilles heel. ............................
I know that whilst extruded Polystyrene is heavier than EPS at around 25kg/m3 being the lightest XPS produced, it is completely waterproof so even if you put a hole in your board you won't get water in the core (unlike EPS). So an 80 litre blank would only add around 1kg to weight(0.08m3 x XPS 25kg/m3 = 2kg versus 0.08m3 X EPS14kg/m3 = 1.12kg)
Being much stronger too (in compression and tension) the lay-up and heel reinforcements could be reduced thereby minimising the overall board weight. The only negative is I undertsand XPS can off gas so enclosing it in a sandwich would have to be dealt with.
Has anyone (Rider, Hoop, MOB, Kimba, Decrepit etc) used or know of anyone who has used XPS for the core construction?
Yep Sausage, I have looked closely at XPS and I can't see it being a straightforward solution.
Firstly epoxy does not like to stick to it. I have seen it used as stringers and reinforcing in hollow boards out of Maui and the epoxy just pops cleanly off.
I have also seen it used in place of divcel/corecel/glegicel in high end SUPs and again the issue is poor adhesion. The result is that on relatively light compressions on the rail for instance, is that the outer shell pops back to its original shape leaving the indented foam behind. On a deck with decal transfer or under rail tape the ding can go undetected etc.
There are ways to help epoxy adhere to the XPS namely carbonising the surface of the XPS. Sadly I doubt its a process that could be adopted to any great benefit to board construction as we know it.
Also think about the thermal expansion properties of closed cell foams approaching 60-80deg Celsius. Expansion can change rocker quite significantly, which is where breathability really helps.
I'd love to hear a more positive experience with the blue stuff - please don't tell me it only stayed stiff for an hour
Select to expand quotesausage said...Man0verBoard said..
...................Core foam is the achilles heel. ............................
I know that whilst extruded Polystyrene is heavier than EPS at around 25kg/m3 being the lightest XPS produced, it is completely waterproof so even if you put a hole in your board you won't get water in the core (unlike EPS). So an 80 litre blank would only add around 1kg to weight(0.08m3 x XPS 25kg/m3 = 2kg versus 0.08m3 X EPS14kg/m3 = 1.12kg)
Being much stronger too (in compression and tension) the lay-up and heel reinforcements could be reduced thereby minimising the overall board weight. The only negative is I undertsand XPS can off gas so enclosing it in a sandwich would have to be dealt with.
Has anyone (Rider, Hoop, MOB, Kimba, Decrepit etc) used or know of anyone who has used XPS for the core construction?
Yes I have built a few boards out if blue eps I did reduce the weight of the glass I used and the thickness of the PVC I had no issues with delam or breakage eg some of these boards have lasted customers 8 years and they changed due to newer shapes and fashion. Hell jumper Glen Alexander used one for a few years and couldn't break it. Yes you Are correct a small wave board blank was 1kg heavier my boards came out 700 gm more than eps boards (80litre) but still people complained about the weight
. A 100 l board would be very heavy say 1.3kg more than EPS
I stopped using it as they changed how they made it due to new enviromental laws and it got heavier added another couple hundred grams
also it only came in a certain thickness and glueing it together added weight and compromised board strength, my supply source company was also unreliable with the stock they carried.
thanks MOB and rider. I have a couple samples of this insulation www.foamular.com.au/ at work and I can stand on a small block about 50mm thick and it'll support my weight (not insignificant). If I did this with eps the same size I would compress it almost flat. It seems like such a logical material to use as a core and the additional weight would not concern me personally to have the strength and waterproof advantages over eps.
The lightest density 25kg/m3 has a compressive strength of 150kpa and is available in 100mm thick x 2450x1250 sheets although it is pink not blue . Come on who wants to build a board from xps?
