. Come on who wants to build a board from xps?
I think everyone is getting a bit too exxcited about what MAY be
As Rider has shown, normal construction is just fine.
It is damn hard to break a 'normal' construction board. Really hard.
The problem is bugger all quality control by a certain factory ........ and/or the fact they give the guys 155.26g of resin and expect them to squeegee that out to every single cm of glass in 2mins ..............
Thanks kimba. So with your expertise would the following lay-up be strong enough:
(Bottom to top)
Epoxy coat/paint
0.3mm veneer
4oz glass
Xps core
2 layers glass 4oz?
Timber veneer
Clear epoxy coat /non skid /paint rails to hide edge feathering of veneer , fillers etc
Pardon my naivety
Putting glass on both side of the veneer would make it stronger, you'd need a total of minimum 20 oz on/around the rails.
I met a Euro who made heaps of 6kg xps boards with no pvc layer, he used to spend 4 months in gnarloo every year. Didn't jump his boards only wave riding, sent me an email with notes and diagrams of all his boards that I printed but it was over 10 years ago. I'll see if I can find the info.
I do remember his most durable board had 3mm pvc on the deck like where your deck grip goes
no comment on xps cores and strength sausage but I agree you need something over the veneer.
you could also swap out one of your 2 layers of glass on the top for innegra.
Enjoying this thread
Trying to reconcile my knowledge of composite construction from a model airplane background to what is done here.
A couple of naive questions/comments. ... Be gentle ;-)
Use of innegra.. Generally this has been selected for impact damage we have used it where typically Kevlar has been used in building wings there are better ways to save weight and build strength and stiffness.
I just did a quick google. From the innegra FAQ
Can I use Innegra? to replace carbon or glass?
No, Innegra should be used with carbon or glass to add impact resistance, durablity, or vibration dampening. It is not a one for one replacement. Careful attention must be paid to your laminate and required mechanical strength. Because Innegra will add ductility it is important to choose the right location for Innegra in your design. If you remove too much carbon or glass you will lose stiffness.
My experience with innegra is that it is a resin hog +++ and difficult to cut and handle. It has worked well between layers of glass due to its thickness.
Has the use of spread tow carbon been considered? It uses much less resin and if sourced from OS comes in at similar pricing to local standard carbon supplies
We have often made test coupons of different materials to get a feel for different lay ups. Happy to spare a little 80gsm IM stiffness spread tow if somebody wants to make up some test coupons
www.rcgroups.com/forums/showpost.php?p=16410909&postcount=531
Cost me around $100 /m
Cheers Jeff
Edit
Carbon po***^^*^rn/ eye candyhttp://shop1.r-g.de/cat/Faserverstaerkungen/Kohlefaser/Spread-Tow-Gewebe
While innegra is not meant to be used to replace glass i think that needs to be kept in context. For eg replacing the top layer of glass with inegra will make a big difference to the board strength.
sups and surfboards sometimes use the 1 layer of innegra + 1 layer of glass on the core in stead of 2 layers of glass.
on the fanatic website they say they have found the innegra/carbon cloth to outperform carbon/kevlar.
Oops I meant 0.6mm veneer not 0.3mm - it was late and I was typing on my phone in bed! Must have had 3mm PVC in my head.
So from bottom to deck
paint
4oz glass / filler
0.6mm timber veneer
4oz glass
Xps core
2 layers glass 4oz and additional carbon/or glass layers to rails and impact/stress areas (mast track, footpads)
0.6mm timber veneer
4oz glass
Clear epoxy coat /non skid /paint rails to hide edge feathering of veneer , fillers etc
Being XPS would you need to insert higher density mast track / fin box blocks or could you do away with these reinforcements?Select to expand quoteKimba said..
Yeah, I made one in 98 when there was a white(no flame retardant?) board blank size available. It was 2500x600x200 / 32Kg/m3 from memory and I just had to glue a small piece for the tip of the nose of a "Flow" type board. I was a real softco and chucked on a layer of Dcell which added to the weight as I still used a normal sandwich layup on top - should have just glassed the blank but I was scared it would ding really badly. I never had any delam issues until I left a board in the wagon overnight and in the morning sun there was a tennis ball sized delam(core/sandwich) which stayed. I never used any special finishing such as scoring/coarse sanding the xps before lamination. The patented hot needle roller is used to combat outgassing in xps surfboards.
Apparently there is a supplier who has just started making the Green version(Dow is blue) in up to 80mm. The green is way cheaper(under 1/2 of the blue price). If there was enough demand they might be able to pump out 200mm thick sheets...
I have done the sums and made some protos in 95 and a hollow xps board looks quite attractive. CNC makes the process a cinch with decent panels sizes to minimise glue joints. I was almost going to make my last board hollow(using a newer method) and then they ran out of 80mm XPS.
Go for it Snags, it is less involved than a sandwich board and much cheaper too! maybe $400-450...
Tim,
So does the needle roller punch holes all over the blank allowing any gas build up a release point to well (permantly under the glass layer? Does the first cloth layer just cover all the pin holes? I'd love to give it a go but the cost alone purchasing all the equipment just to make the thing would be cost prohibitive - I assume I couldn't do it without vacuum bagging etc.
What do you mean by "hollow xps board" too?
Select to expand quoteR1DER said..
Putting glass on both side of the veneer would make it stronger, you'd need a total of minimum 20 oz on/around the rails.
I met a Euro who made heaps of 6kg xps boards with no pvc layer, he used to spend 4 months in gnarloo every year. Didn't jump his boards only wave riding, sent me an email with notes and diagrams of all his boards that I printed but it was over 10 years ago. I'll see if I can find the info.
I do remember his most durable board had 3mm pvc on the deck like where your deck grip goes
I couldn't be certain but all my SB timber boards don't have an additional layer of glass over the veneer - it's only a seal coat (see photo below). Hence if using XPS core you just do away with the PVC sandwich layer. Maybe a 3mm PVC layer on the deck in lieu of the timber veneer would be a stronger option too as you suggested - much easier to work with than feathering and forming the timber veneer I suspect*.
*Of course I only have experience in snapping boards and have a very limited knowledge or experience in building a board so I really have no idea what I'm talking about!
Here's one I prepared earlier!
Hello again Ian
sausage I am yet to see a board that did not require some work to the folds, bends etc regardless of whether it was timber or pvc.
Select to expand quoteGestalt said..
sausage I am yet to see a board that did not require some work to the folds, bends etc regardless of whether it was timber or pvc.
Gestalt,
I have no experience with PVC but I know how difficult it can be to bend &/or form even thin timber veneers two ways. Which was easier for you when you built yours?
Heat Bending
PVC free foam sheet can easily be bent by using localized heating. It is recommended that the sheet be cut to final dimensions and/or machined prior to heat bending.
there is no straight answer.
it depends.
it depends on the type of pvc and it depends on the shape of the board.
at a minimum both veneer and pvc needs to be cut to get it to fold around the tighter curves or you get creases. some hardcore foams like dcell are easier to work with and can be wrapped down the rail and stuck in place but you still need to cut triangles out of the flat sheet. other hardcore foams need to be heated to be folded.
timber is no different. it needs to have triangles cut out of it but I need to stress how thin .3mm veneer is. it looks like paper. it's not as thin but it is very thin.
the important thing is that whatever you use you wrap around the rail. this is the point where the very experienced guys (not me) are much faster and know what to do where and when.
the other thing to ask before you even talk layup and materials is. are you hand laminating or vacuum bagging?
like designing a building, everyone will give you a different answer.
There's very few instances where you would cut PVC to wrap it around a blank. If you do cut it when heat treating it can tear very easily. A bit like when you get a hole in a monofilm sail. It's a tricky technique to learn but once you have it, it's really quite quick and easy.
Another tip I would give on building boards is to be careful listening to forums. You will get a lot of advice from people that don't actually make boards.
Making a board and seeing one built are 2 very different things.
There's a lot of good stuff on youtube and most of the vids on manufacturing from the manufacturers are good, like the Carbonart one posted on here earlier. There's also some good ones from the Nelson factory.
Good luck
Select to expand quotesausage said..
Oops I meant 0.6mm veneer not 0.3mm - it was late and I was typing on my phone in bed! Must have had 3mm PVC in my head.
So from bottom to deckpaint4oz glass / filler0.6mm timber veneer4oz glass
Xps core
2 layers glass 4oz and additional carbon/or glass layers to rails and impact/stress areas (mast track, footpads)
0.6mm timber veneer4oz glass
Clear epoxy coat /non skid /paint rails to hide edge feathering of veneer , fillers etc
Being XPS would you need to insert higher density mast track / fin box blocks or could you do away with these reinforcements? Kimba said..
Yeah, I made one in 98 when there was a white(no flame retardant?) board blank size available. It was 2500x600x200 / 32Kg/m3 from memory and I just had to glue a small piece for the tip of the nose of a "Flow" type board. I was a real softco and chucked on a layer of Dcell which added to the weight as I still used a normal sandwich layup on top - should have just glassed the blank but I was scared it would ding really badly. I never had any delam issues until I left a board in the wagon overnight and in the morning sun there was a tennis ball sized delam(core/sandwich) which stayed. I never used any special finishing such as scoring/coarse sanding the xps before lamination. The patented hot needle roller is used to combat outgassing in xps surfboards.
Apparently there is a supplier who has just started making the Green version(Dow is blue) in up to 80mm. The green is way cheaper(under 1/2 of the blue price). If there was enough demand they might be able to pump out 200mm thick sheets...
I have done the sums and made some protos in 95 and a hollow xps board looks quite attractive. CNC makes the process a cinch with decent panels sizes to minimise glue joints. I was almost going to make my last board hollow(using a newer method) and then they ran out of 80mm XPS.
Go for it Snags, it is less involved than a sandwich board and much cheaper too! maybe $400-450...
Tim,
So does the needle roller punch holes all over the blank allowing any gas build up a release point to well (permantly under the glass layer? Does the first cloth layer just cover all the pin holes? I'd love to give it a go but the cost alone purchasing all the equipment just to make the thing would be cost prohibitive - I assume I couldn't do it without vacuum bagging etc.
What do you mean by "hollow xps board" too?
I have made an XPS board and a Veneer board, but never combined the 2 so I would be foolish to give you a layup stack that was guaranteed to work. Veneer over xps did have good puncture resistance but some test pieces would be the way to go, even just to get a feel for each of the materials.
I've still got a few sheets of Dow xps as well as veneer so if I get the chance I might be able to layup a few configurations. Rider would be the one to ask about a layup having made more than 1 as well as getting the lowdown from his euro mate.
The holes are actually melted in the laminate to vent the core...Thermoventing. Here is the blurb from the XTR site:
"THERMOVENTS"
WHAT IS "THERMOVENT" TECHNOLOGY?
"Thermovents" are small vents that penetrate the fiberglass to the surface of the foam allowing gas to escape when hot (all XTR blanks have gas inside each small cell, it makes the surfboard more responsive and resistant to aging).
Water cannot penetrate the foam because XTR is closed cell foam, only a small amount of moisture will get inside the vents, nothing that will alter the weight or strength of your surfboard.
WHY DO SURFBOARDS NEED "THERMOVENTS" ?
Epoxy Pro has been making surfboards with Extruded Polystyrene Foam since 1991. All the surfboards made with these materials by Epoxy Pro or any company will in the long run bubble or blister under your front feet or rail due to the gas inside the foam.
Hundreds if not thousands of stoked customers were eventually calling with a complaint about a bubble or a delamination on their surfboards.
Many sleepless nights and countless ideas were spent trying to solve the bubbling or delamination problem, until one day, in June 2002, Javier and his son Diego started to vent a surfboard that was a year old and start a set of temperature tests until they discovered that the surfboard did not bubble!! Even at 140'F.
Since then the vents have been perfected and also added to the rails of all short boards in 2004.
HOW THERMOVENTS ARE APPLIED TO THE SURFBOARD?
Javier has designed and also patented a special tool that reaches 200'F and penetrates the glass all the way to the foam. This tool is applied after the surfboard has been finished.
This tool is made with special needles that conduct heat to melt the outer layers of the fiberglass and resin without debilitating the surfboard. It takes less than 1 minute to apply the vents and they are almost invisible.
Not sure if I would want small holes all over the hul...
Re.layup
The better you are at glassing, the smaller the returns from vac bagging a boards laminate.
I saw on swaylocks a lot of builders have gone back to plain wet layup, to save time and material expense - they are still getting the same or better results. To tell you the truth, I have only vac bagged the outer laminate on 2 boards and one of those was veneer.
On my veneer board I used .6mm Aus pine and used a 4oz zipper layer(between veneer and pvc) with no glass over the top, just sealed it with resin. This is similar to the starboards although they do have a lighter zipper and some glass on top in high load areas. If I did another veneer board I would sandwich the veneer with glass as they can dry out and split just like the starboards, JP's etc. They quite often rely on full deck stickers to create a water resistant membrane on top...
"Hollow XPS Board" - a board built with xps that is hollow Seriously though, I need to try a full sized board to make sure it can work in practice and not just theory and test pieces(or my dreaming the last 15 years). FEA analysis might be helpful if I can get accurate xps data!
Tim,
Thanks - would be great to see how those test samples turn out.
Also found this in response to the XTR FAQs
HOW THERMOVENTS ARE APPLIED TO THE SURFBOARD?
Javier has designed and also patented a special tool that reaches 200'F and penetrates the glass all the way to the foam. This tool is applied after the surfboard has been finished.
This tool is made with special needles that conduct heat to melt the outer layers of the fiberglass and resin without debilitating the surfboard. It takes less than 1 minute to apply the vents and they are almost invisible. end of cuote.
SUPflorida:
I keep hearing that...but I have two windsurf wave boards (1993 & 1994), a surfboard (1996), live in florida...all three have baked on numerous occasions in the camper shell of my Dark green Dodge 4X4... and these three, as well as many others were made with the closed cell foam purchased from Doug Wright years ago and have never delaminated from the south florida heat to this very day...all done with RR epoxy.
finsider:
Closed cell extruded foam is great for the fact that it does not absorb water, but it also does not absorb resin like an EPS foam will. The XPS also has a "finer" surface so getting proper adhesion to the resin and fiberglass is the key to making a board this way. I have heard of people scuffing the foam to promote resin adhesion. It can and has been done, and works beautifully. It is however more tedious of a job which is why some shapers stick to EPS.
From a shaping standpoint it is a tougher cut, but extruded foam will not come off in chunks like some lightweight EPS will.
SUPflorida:
I didn't rough up the foam or do any special treatment...at least sanded down to 120 probably 220. To me it was a heavier alternative to vacuum bagging Divinycell on 1 lb EPS ...more weight but faster build and no water absorption issues.
getsupngo:
The trick is to keep the lighter stuff protected from too much shear, cell crushing, and heat.
The heat is not much of a problem if the cells dont ever get crushed. Too many crushed cells equals a pocket of gas that expands readily with heat. Protect the cells from being crushed with a thick strong sandwich over it or just dont use xps wherever its cells will eventually get crushed.
The sandwich can also help with shear by keeping the board from overflexing. A rough texture before glassing and plenty of epoxy saturation into it also helps shear.
So the issue of XPS off-gassing only happens where compression (cell crushing) of the foam happens i.e. rails and foot pads / rear of deck. If you can eliminate the compression of the blank then I assume you wouldn't need to make the pinhole penetrations nor worry about areas bubbling / delaminating. Maybe if you could add some sort of super thin breathable layer (think similar process to capilliary action but with air) that still has adhesion capability using resin. Breathable layer is then connected to something like a goretex vent. Of course anything that can breathe can take on water so maybe just reinforcing the pad areas / rear with a PVC layer would suffice.
yet again here I am confirming my limited knowledge. 
It's doing my head in!
Select to expand quoteGestalt said..
at a minimum both veneer and pvc needs to be cut to get it to fold around the tighter curves or you get creases. some hardcore foams like dcell are easier to work with and can be wrapped down the rail and stuck in place but you still need to cut triangles out of the flat sheet. other hardcore foams need to be heated to be folded.
Select to expand quotehoop said..
Another tip I would give on building boards is to be careful listening to forums. You will get a lot of advice from people that don't actually make boards.
Making a board and seeing one built are 2 very different things.
Good luck
Absolute GOLD Hoops! Couldn't agree more 
Select to expand quotebarn said..Gestalt said..
at a minimum both veneer and pvc needs to be cut to get it to fold around the tighter curves or you get creases. some hardcore foams like dcell are easier to work with and can be wrapped down the rail and stuck in place but you still need to cut triangles out of the flat sheet. other hardcore foams need to be heated to be folded.
Ha ha ha
Select to expand quotehoop said...
There's very few instances where you would cut PVC to wrap it around a blank. If you do cut it when heat treating it can tear very easily. A bit like when you get a hole in a monofilm sail. It's a tricky technique to learn but once you have it, it's really quite quick and easy.
Another tip I would give on building boards is to be careful listening to forums. You will get a lot of advice from people that don't actually make boards.
Making a board and seeing one built are 2 very different things.
There's a lot of good stuff on youtube and most of the vids on manufacturing from the manufacturers are good, like the Carbonart one posted on here earlier. There's also some good ones from the Nelson factory.
Good luck
did you watch the carbon art video? Must be one of those very rare reasons.
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
Select to expand quoteGestalt said..
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
YEAH ! So let it go !!
I'm glad I'm not going to Burrum who wants to hear you rant and rave.
I can see cuts in the tail section of Nelson factory deck sandwichs too in the photos?
Surely part of the fun of homebuilding is the experimenting and seeing what happens anyway isn't it - so get in the garage and start maniacally laughing as you concoct your evil board of mass enjoyment. And if/when it breaks, fix it or build another one...or buy one...preferably not one without glass...or dry glass...or ready made holes hidden inside
Select to expand quotehoop said..
There's a lot of good stuff on youtube and most of the vids on manufacturing from the manufacturers are good, like the Carbonart one posted on here earlier. There's also some good ones from the Nelson factory.
Well for inexperienced people maybe. I always tell new staff to watch the Nelson vids to show them how it is not done and to figure out what it is and why. They don?t manage to come to 20% but it sets them thinking. This usually includes where the guy is using 10cm thick EPS flip flops instead of using movable stands. There is not one single thing that we don?t do different. Which is why we do not publish such video?s. The trick or system how to avoid cuts in the deck sandwich is one of the very minor ones.
The CA video I had not seen before. It is also very different to how we build but the board in question is a slalom board so not really relevant. I presume they use different techniques on waveboards, without a vacuum table to be able to adapt the rocker.
Select to expand quoteRealistic said...Gestalt said..
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
YEAH ! So let it go !!
I'm glad I'm not going to Burrum who wants to hear you rant and rave.
no ranting and raving at burrum mate. Ecept for when someone sails up the course the wrong way.
maybe before judging you should come to an event.
that said, i reserve the right to respond to the sarcastic commentary aimed at me in this thread.
and i stand behind what i've said with regards board building. Watching the carbon art vid makes me very comfortable and so far show cases methods i am very familiar with.
that's it from me in this thead, i've got more important things to deal with.
Select to expand quoteGestalt said..Realistic said...Gestalt said..
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
YEAH ! So let it go !!
I'm glad I'm not going to Burrum who wants to hear you rant and rave.
that's it from me in this thead, i've got more important things to deal with.
So you keep saying.
Select to expand quoteGestalt said..Realistic said...Gestalt said..
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
YEAH ! So let it go !!
I'm glad I'm not going to Burrum who wants to hear you rant and rave.
no ranting and raving at burrum mate. Ecept for when someone sails up the course the wrong way.
maybe before judging you should come to an event.
that said, i reserve the right to respond to the sarcastic commentary aimed at me in this thread.
and i stand behind what i've said with regards board building. Watching the carbon art vid makes me very comfortable and so far show cases methods i am very familiar with.
that's it from me in this thead, i've got more important things to deal with.
GOOD!
You've had some good ideas and valid comments but you've also said a lot of rubbish which I find quite sad and misleading for budding board builders.
Your expertise seems to be from watching other people make boards for you or regurgitating information from the Internet, it's evident that myself and other board builders can see right through you, but sadly other inexperienced people can't and actually believe how you portrait yourself and some of the rubbish you say and I just don't think that's fair! it's great for your ego though.
I can't believe when I exposed your lack of knowledge of the exact amounts of materials used in your own board you still went on to sprout and give advice, if that was me I would have quietly disappeared and looked for a small crack to hide in.
With the amount of posts you've made I doubt this is your last post in this thread, you can't help yourself
Select to expand quoteWitchcraft said..
The CA video I had not seen before. It is also very different to how we build but the board in question is a slalom board so not really relevant. I presume they use different techniques on waveboards, without a vacuum table to be able to adapt the rocker.
Bit of inside info...they use tables for wave too. They make up custom cnc'd rocker tables for each rocker/bottom shape in the production models, so no twist or deviations in the rocker set ups - and new table tops made for new year models. You can see a few of the diff tables in that vid.
Be great to share with us what the incorrect practices are in the Nelson vids for all the armchair builders playing at home? (must admit I haven't watched them as yet so maybe they're obvious?)
Select to expand quoteRealistic said..Gestalt said..
Enjoy the frat party guys. It's a shame people let ego get in the way of a conversation.
YEAH ! So let it go !!
I'm glad I'm not going to Burrum who wants to hear you rant and rave.
Well done "CLOWN" this guy may not know what he's talking about in regards to board building but goes out of his way to organise a great event year after year, Burrum should never have been brought into this thread.
Select to expand quoteMcSmurfin said..
Bit of inside info...they use tables for wave too. They make up custom cnc'd rocker tables for each rocker/bottom shape in the production models, so no twist or deviations in the rocker set ups - and new table tops made for new year models. You can see a few of the diff tables in that vid.
Hmmm, at least a 10 for effort. I can see various problems there for different bottom shapes and getting the deck sandwich around more tucked rails but presume they solved this. Considering there still is tension in the board when vacuumbagging and the board jumps back when releasing the pressure I prefer a different method which leaves me more freedom to adapt a board but it certainly has some good points.Select to expand quoteMcSmurfin said..
Be great to share with us what the incorrect practices are in the Nelson vids for all the armchair builders playing at home? (must admit I haven't watched them as yet so maybe they're obvious?)
Well there is not one single movement we do the same. I will not mention them all but one little thing is to mount the finbox reinforcement block after the sandwich. Why not mount it at the same time? Saves a step, you do not cut away so much inner laminate and the bonding area between reinforcement and sandwich is much bigger. Also you can use a lighter PVC for the block than for the sandwich.
Also someone mentioned cutting the end of carbon reinforcement too much across the board and not in a point gives a potential weak spot. This was something that a worker in our production factory had not understood well either and was corrected later, but in the Nelson video you see it happening with much thicker carbon.
Another thing is that our CNC also shapes the rails, all reinforcements and deck sandwich fold out incl. the cuts to remove excess material to fold it over at the nose. The program knows the flexibility of the sandwich and just makes the bear minimum of cuts. And all box recesses are made by CNC too, to the 0.1 degree and 0.1mm.
There is lots more and more important things but I want to keep them to myself. The use of Dyneema and how we use it is actually just one of many things. The strength from within is much more important for longevity. To repair the outside is much easier.
