Friday, December 23, 2011

Open Office version of BoardOff

I've had a few emails from people asking if BoardOff will run on any of the free spreadsheet programs. I've had a bit of time on OpenOffice Calc but never for macro creation and so I did not realise that it actually implements a version visual basic for apps (VBA) called OpenOffice Basic which is very close to MS VBA.

I did a trial conversion over to openoffice and found that 2 key objects are implemented differently. The Range Object and the Application Object. The range object does have the row count property used in the SPLINE function in BoardOff but its a simple matter to fix that. Once that is done all the calculations work!!!!

There are a few things to iron out (charting on multiple axis screws up and the load,save, merge dialog boxes need to be convert to the Oo equivalents and the macro buttons need to be re-added).

I don't think this is a big job and so I will have a crack at it over the next week or so and see if I can't get an Oo version out there. This should make it possible to use BoardOff on Mac's and Linux machines as well.

I'm also toying with the idea of making a web-based version of board off to get a community of ideas and designs going online so we can compare and share designs. It would also create a change to make BoardOff more user friendly

Cheers
Matt

Thursday, December 22, 2011

Musing on concave

I had a chance to try out the new board at a great flat water spot about 4 hours north of Sydney called Old Bar. We had great wind there and so got to try the new board out on the flat water as well as in the surf.

Overall very happy despite the rocker table mess up the board feels great despite being different.

One thing I noticed is that the narrower tips seemed to compensate for the lack of rocker when it came to handling the chop. I working theory on tips is that because when your edging the hard the board is more vertical than is it horizontal, the curve of the rails toward the tip is works like the rockerline in the case the board is being ridden fairly horizontally. The net result is the the board rode over the chop nicely didn't through up much spray.

The other plus of the narrow tips is that it carved really well on the waves. Because there is more pressure on the wider mid section of the board its easy to balance your weight and pivot the board about the mid point rather than drive the carve from the back fins. This meant it turned on a dime!

I rode this board and my other board back to back and I could not really detect any difference as a result of the absence of concave. This has got me thinking about whether concave is worth it when working with stiffer core material.

My understanding is that concave does 2 , maybe 3, things:

i) It adds stiffness 'artifical thickness' which the BE equation analysis shows a doubling of stiffness when the concave is equal to the thickness of the board although the maximum stresses on the top and bottom layer as a result of the concave are very different (the top experiencing greater stresses - not good when it comes to compression). The stiffness is important for foam cores where the core itself contributes nothing other than to keep the laminate separated and locked relative to each other. The stiffness of the core means this is not so critical.
ii) It flattens the rocker line down the center of the board relative to the rails. This means earlier planning.
iii) Concave also means that the angle of attack of the rail is greater than that at the middle and so the rails bite into the water better and there is the possibility that can reduce the losses associated with cross flow on the underside of the board resulting in more lift on the toeside edge (helping dig the healside in) and possibly more forward momentum if the water flow is redirected towards the tail. However, I don't have any sense of how large these effects are.


On the negative side:

i) Concave adds drag because of the increased angle of attack.
ii) The increased angle of attack means your more likely to catch the toeside edge when you land and have the board too flat. This is the reason that some boards end up having slight bevel on the rails or take then edges from concave to convex as they approach the edge.
iii) Although there is a weight penalty, the stiffness issue can be addressed with additional reinforcement over portions of the board (say the middle)


So what's the so what of this?

i) For wood cores concave may be less effective of desirable than foam cores boards that use it as artificial stiffness.
ii) In wood cores, maybe the edge holding benefit of concave might be replaced with simpler carved channels close to the rails.
iii) The early planning advantage may be partially addresses by the rockerline design. The current rockerline I'm trying is like the NHP where most of the curvature is in the middle 25% and from there to the tips is quite flat. This gives a good planning surface towards the tips rather than the middle so may require a different stance to get started but should benefit early planning potential.


Sunday, December 11, 2011

Board #3 Debrief - Do's, Don'ts and Don't Knows

Time to capture some learnings from the project what worked and what didn't and what I'll do differently next time. Here's the  key

 + are what worked
 - what didn't
* neutral feeling about it
!! idea for next time.

Core

I used Paulownia wood planks 1400x100x6 mm. The deck was built up from 2 layers.

++ cutting a template first so that the core shape could be routed out was perfect. Very quick and efficient. Its important to get the hole spacing for your fin bolts exact because when the screws are off center even the smallest amount its screamingly obvious when you don't have an opaque surface.
+ the wood is stiff. The elastic modulus of the wood is quoted at around 5-7 GPa compared to Klegecel which is effectively zero. e-glass in epoxy comes in at around 15 GPa (typical) but the core is 40 times thicker than the layer of laminate to its contribution to stiffness is huge. This means less layers. I used x 200 g each side but have heard of someone using 2x 160g.
+ using double sided tape to hold the core in place while the shape is routed out.
* exposed wood looks great but the 2 distinct decks don't look so good together - this is obviously a personal preference.
* I left the planks at 100mm wide rather than trimming to 50mm and reassembling them. !!Thin planks look better and apparently help break up weakness in the wood.
- I really needed to thin it down to less that 10 mm as this stuff is really stiff. Using an electric plane and 40 and 60 grit sand paper was time consuming and left an uneven surface as the electric planer leaves tracks on large areas like this and they need to be sanded out. !! Use a router and jigs to do the bulk of the shaping on the core and then an orbital sander to take unwanted sharp edges off.
- Sealing the core before glassing. I think sealing is the right thing to do but I did not let it cure long enough and so it has not sufficiently gelled by the time I placed it on the table. The result was that the white pigment in the underside sealing coat diffused into the graphic inlay and obscured parts of the image. !! Let it cure for at least a few hours so that it is tacky but notquite set yet.
- I left the tips at 6mm and I think that this is too thick to get enough flex. Will have to wait and see.
- building the core up from 2 layers, while straight forwarded, added lots of time to the process. (gluing the planks, routing, sanding and then gluing the layers together. A single piece carved into shape is much easier if you can carve it efficiently.
--- the stiffness of the wood when glued into the 400mm width was too much for the perspex (plastic) sheet used on the rocker table surface and it deformed. This resulting in concave vanishing and rocker reducing significantly. !! Either change to using Formica for the rocker surface of brokite style 2 layer mould to encase the core pieces while they set.

Rails

I poured the rails with the same epoxy I used for laminating. I didn't add any thickener to it because I wanted to keep them transparent so the graphics showed through and didn't want to run the risk of reducing the strength. Given they were being poured into a channel I didn't see any reason to use q-cell etc to improve adhesion. It used around 250 g of resin which is actually slightly more expensive than using ABS plastic strips (hence the reason to use q-cell in them). Alternative pouring materials I've heard of are liquid polyurethane (can't remember the exact name) but think that is had a shore hardness rating of 70D

++ clear rails look great. Graphics shine through when sun is behind it.
++ using the router to create the channel gave a good uniform width rail and allowed the laminate to be laid past the rail so no steps that might have accumulated resin or resulted in the glass bridging.
++ mixing the resin very slowly and pouring the resin in really slowly into the channel meant that I had no air bubbles trapped in the resin. I used a plastic tomato sauce squeeze bottle with a pointy nozzle to direct the resin.
+ cutting the slot for the rail all the way through the material and using tape on the underside to create the channel work OK. Only hiccup was that the tape had a couple of wrinkles which of course meant wrinkles on the surface. This can be overcome with better technique, I'm sure. Maybe put tape down first with adhesive side up and then place the core pieces on top.
* I'm still be be convinced that pouring the rails is the best approach. It was critical to get the table level and the core an even thickness to ensure that resin didn't pool and overflow while draining away from another place. I didn't manage to do this and so a lot of work was needed to sand it back and refill.
- There is no way around the waiting time for curing. And because I had to top it up I had to wait again. This puts a lot of delay in the process.


Graphics

+++ Inlays printed on 'silk' ( I haven't heard from the supplier about the actual material. It feels like a very thin peel ply). Looks brilliant, super easy to work with and cheap.
-- no scratch protection or UV protection and requires you to do all the surface finishing that wouldn't be necessary if protective bottom and top sheets were used. 
!! would still like to get PBT bottom sheet to avoid have to do all the surface finishing that was royally screwed up.


Laminate and vac bagging

++ as much as I hate working with it and its expensive (cause it has to be thrown away) tacky tape seals like a champion. The only viable alternative I can see is to put the entire table/mould inside a the bag so that tape is not necessary. I'm keen to have a go at this for next time. !!Maybe creating a fibreglass mould for next time.
++ doing the laminating in one go rather than top then bottom as I did previously. Saved an entire curing cycle.
+ using paper towels as breather/bleeder material seems to work fine. Despite the surface coming out a bit dry (and I think that this may be due to the wood absorbing resin) the finish was nice and uniform.
* Peel ply is very effecting in letting excess resin flow through it. However, I think that may too much as able to flow out and so !! next time I'd like to try using perforated release film instead of peel ply. The release film lets less resin flow across it and so holds more in the laminate. Because of the wood soaking up lots of resin, holding it in there might be a better idea. It also means less is required to finish the surface as its already quite shinny.
* 27 mmHg may have been too much pressure and resulting in the dry laminate on top. Not sure, I need to explore more. It took about 20 mmHg to get the board to conform. If the planks are being glued together (along the length of the board) at the same time as laminating then the problem would go away.
? Resin. The top layer of laminate appeared too dry after it came off the table and there are a few different theories going around in my head. One being that the resin soaked into the wood core because of the long cure time ( I used slow hardener which has a 45 min pot life and multiples of that when its spread out). Maybe this gives too much time and allows the resin to be absorbed into the core. Although, this was not the case on the underside which had a good quantity retained in it. Maybe I need to use a more viscous rather than less viscous resin to prevent too much flowing out when its under vacuum. I followed up the lead from a discussion about the viscosities of FGI and west system 'entry level' resins but the data sheets for the FGI resin quote a huge range for the viscosity 110 -1500 CPS. The West System'2 105/205 is quoted at 580 CPS. I don't understand why the range is so big. A question for FGI.


Rocker table

+++ The matching metal frames, the jig setup, working height very low, the ratchet straps to apply lots of clamping pressure to the jigs.
--- The rocker table surface for wood cores was a disaster and changed the rocker and concave to flat and flat.
!! add 400w workshop lights ($14.95 each at bunnings hardware) to be able elevate the temperature for post curing. Needs a temperature controller for switching on and off.
!! change the surface to either Formica laminated to the ply or use a brokite style construction where a bottom and an upper layer of perspex is laid over the core and the whole thing placed inside a vac bag. The 2 layers together and the symmetrical pressure on the mould should be enough to prevent the distortion. It also works to hold all the pieces together and so makes it possible to do just one gluing and laminating pass instead of the 4 needed to do the rails, 2x cores + 2 cores together, laminating and finishing.


Surface finishing

Really not sure how to turn this around an would like to avoid it as much as possible by using PBT bottom sheets top and bottom ideally. Reality is that probably will only use it on the bottom if I can get hold of it (due to cost).

++ Perspex sheet on the bottom results is a great finish on the board straight off the table.
--the sanding I did made the surface murky. !! do another sanding pass with greater than 600 grit paper and maybe buff it.
-- using epoxy to do a final coat left the surface uneven, 'wavey' as it did not self level very well. !! Maybe try thinning the epoxy of finding good advice on UV stabilised varnish.


Weight

+2.3 kg without accessories. 0.4 kg heavier than foam core board. Can't complain about that.

Accessories

+++ Antig99 footpads and fins. Hard to be on price and work fine. I've give the fins a good flogging in the sand and hit a few rocks and they handle as well as the fibreglass fins do maybe even better without the screen printed logos to show wear.

Saturday, December 10, 2011

Wrap-up - bill of materials

I just did a bit of a round up of the total cost of the board.

Other than the cores, the other material was bought in one-off quantities so no volume discounts.
Due to the transport costs there would be some economies of scale by buying 2x the quantity. Also, buying the cores in 100x1400x6 planks was expensive. I think that buying the kiteboard blanks or larger planks an milling it myself would save a lot.

Also, buying larger quantities of resin reduces (4 kg vs 1 kg) saves around 30% and buying 4 sets of pads and fins reduces the cost buy around $20 per set.

There is also scope to reduce the volume of resin used.

I don't believe there is any discounts on other materials until you start to buy industrial quantities.

So with the discounts I can access I reckon $250 for a complete board with accessories might be possible.

I'd be very interested know how this stacks up with other peoples costs.


Finished!

Finally finished!




Very happy with the graphics. Other stuff............

I pfaffed around with the final surface finish quite a bit and I have to say that it let the whole project down. But, at least now I have something concrete to get help with.

The bottom side came off the rocker table very slick with a great shine on it. There were a few small voids in it but not enough that I was worried about it letting water get in. The top side came out fairly dry of resin (at least that's how it looked). So, I thought that I do some final work on the surface finish on both sides to see if I could get a high quality finish.

I sanded the top side with 400 then 600 grit wet and dry and sanded the underside with just the 600 grit (to see if that roughness would have any impact of the lustre of the finish). It certainly did. The top looked milky. The bottom not nearly as much but the shine was definitely taken out of it.

I went bought some Gold Spa yacht varnish from Witworth Marine but the weekend staff were not particularly knowledgeable on the varnish but the convinced me to try alternative one that was a polyurethane varnish and is supposed to have better UV protection. Seemed to make sense. Problem was that the varnish was too viscous to get into the small voids and all it did is make them more pronounced. I tried it on a test piece first so it was no dramas but it meant that I decided to just put down a thin coat of epoxy.

I thought about thinning it out and in hindsight should have. Although it did give a very nice clear, shinny finish it did not self level very well (maybe because the FGI resin is relatively high viscosity?) and so it left an uneven surface that I am none the wiser about how to fix. In the picture of the underside at the bottom of the photo you can just make out some of the brush marks. A close inspection of the board shows a lot of these and it looks pretty ordinary. Chalk this up to experience.  

So, I'll do a little googling around to find out more but I am officially calling this board finished and started to think about the changes I'll make next time round.

The biggest success out of all of this was the graphic inlay. Easy to apply, looks great and cheap ($25 per side)






Wednesday, December 7, 2011

Board #3 comes off the table

After leaving it on the table for 36 hours (its been wet here so I left it in the evacuated environment of the vac table, safely away for the moisture - go the vac pump which run reliably for 36 hours!!!).

Overall I'm pretty happy. Other than the rocker/concave disaster, lots of things I tried worked well.

Sorry about the weird orientation of the images, they got rotated in transit and not sure how to change it.


Peel ply peeled back

Off the table - the footpad reinforcements are visible due to the different density weave of the 4oz s-glass

Eureka!!!!! Look at that shine right of the damn perspex - what a love/hate feeling I've got right now.
The bottom and the graphics looks awesome. There's a lot to be said for getting the amount of resin right and not letting too much get squeezed out.

The top surface was another story. I'm going to need to ask around about this one cause I'm not really sure why it came out with what appears to be too much resin extracted. In the image below you can see the white weave of the fibreglass that is not fully saturated with resin.


Slightly too dry top surface. What the?
Not quite sure what the culprit is here. Some possibilities that come to mind are:

i) The clamping pressure was too high? 27 inHg = c. 90% of a vacuum.
ii) The wood drank up the resin from below and left the voids
iii) The bleeder material is too effective? The paper towels are very absorbent material and so maybe there was excessive 'wicking' up of the resin.
iv) Too little resin in the first place. This didn't seem to be the case when I wet it out but perhaps when the resin got absorbed it was a different story.....


To fill the voids I literally did a 'hot coat' of resin and pushed it into the weave by dabbing it vigorously with a end of a paint brush.

Hot coat, I believe, refers to a polyester resin mix that has a bit of extra catalyst in it so that it goes off quickly. That doesn't work with epoxies but heating the epoxy up sure as hell does. When I was pouring the inserts the other day I put 70 gms of epoxy in the microwave for 15 seconds. It thinned out brilliantly but it went off in about 5 minutes. So I used the same idea here. I heated up 70 gms of resin, put it in the microwave for 10seconds. As soon as it hits the board and the surface area of the resin expands it looses a lot of the heat to the atmosphere so I figured it would be ok to leave it in the pot for 1 minute before I poured it as this would let the reaction that is speeding along due to the elevated temperate progress. It seemed to work ok and after I poured it by about the 15 minute mark it was already very tacky. Given it was slow hardener with a pot life of 35 mins it certainly was a faster process.

I have read, and this is in the category of Trev reckons, that for each 10 degrees you reduce the temperature of the epoxy below the design ambient temperature you slow the curing by a factor of 2. It would seem that raising the temperature by 10 degrees has a more dramatic effect.





Rocker Table Disaster

Despite the workflow running smoothly, albeit slowly, the major failure that occurred was the deformation of the rocker table surface under the stiffness off the wood.

The table surface I've been using is 4mm ply with 4mm perspex over the top. The ply gives the stiffness required to get the nice parabolic concave profile that the perspex can't do on its own and in addition the perspex gives a brilliant finish on the surface right off the table.

For a foam core that has effectively zero stiffness the perspex was strong enough that the force required to bend the foam core was not enough to bend the clamped perspex. For a wood core with no rocker its also strong enough but as soon as you add rocker the lateral stiffness of the core cores through the roof even though the grain runs perpendicular to it. The net result is that the perspex lifted off the ply and through the clamping pressure of the jigs and so about 1 cm of rocker vanished in an instant!!!!!

Board at the lower side of image. Shadow shows the extent to which the perspex lifted off the surface


Rocker reduced. This gap should represent around 1/2 the rocker. which puts it in the 2.5 cm vicinity



Concave all but vanished!!!
 So not the board that I was aiming for but there are a number of great outcomes from this.

i) I've been very curious about how concave affects the performance (other than stiffness) so now I have an unexpected chance to see first hand. The board is quite similar to board #1 but without the concave. Rocker is about the same. So it will be possible to test by riding them back to back.
ii) Its increased my commitment to being able to put the entire table (or surface) is a vac bag so that I don't have the asymmetrical forces on the surface doing exactly what it did hear ( again another tick for their Royalty Highness's at Brokite)
iii) Lots of other things worked spectacularly well: The workflow setup, all other aspects of the rocker table, laying up both sides at once.


Not the outcome I was designing for but some great real experience !!!!!

Matt

Tuesday, December 6, 2011

Under the pump

We had an unexpected break in the weather and so yesterday I took an early mark and got board #3 onto the rocker table. Overall things when smoothly with the exception of the rocker table surface which deformed under the pressure required to get the concave into the board once the rocker had applied.



Getting everything ready to avoid wasting time once the curing starts


First thing was to assemble the rocker table and clamp it tight with the ratchet straps.



Note the rocker table surface is 4 mm perspex over 4 mm ply wood. The perspex in this clamp style rocker table bends sharply over the middle jig and so the smooth 'beam' bending on which the rocker calculations don't work and you end up with a 'triangular' concave rather than the (almost) parabolic profile.

Ratchet straps worked well, The metal pole over the top was just to assist applying clamping pressure to the jigs in the middle where the greatest force is needed. It didn't get in the way too much because there was a lot of clearance under it.

Next I sealed the core with resin. Couple of reasons for this. Firstly, I want a white background for the graphics on the underside and secondly the wood drinks in quite a bit of resin and I have read that this can also lead to air bubbles in the laminate (though with temperatures falling its more likely to be drawing air and resin into the core rather then expelling it). It took around 100gms of resin to do both sides.
The as the pigmented resin did soak into the core the coloration became a translucent white with wood grain showing through. I was wanting opaque white but it was not to be.

Then to the layup. I'm using 200gm e-glass 0/90 degrees. Two layers both sides. The resin/fibre ratio for this is around 50% so given the board size I figured that the ideal would be around 200gms resin per side + 10% for excess required to saturate the glass. This turned out to be spot on even with the decal insert.

On the bottom, I put the graphics in between the 2 layers. The material the graphics is printed on is like thin peel ply and so as soon as it touched the resin it started to wick it up and it saturated with almost no pressure being applied. I did pour some extra resin on it to make sure. Any excess here will be drawn into the next layer of glass and excess beyond that will be sucked out under vacuum.



Graphics ( blurry)
 Then the core and top 2 layers plus the footpad reinforcements.


top 2 layers pre-bagging
I am not very quick with the resin work and so but this stage it had been over 50 mins since the first layer of cloth was wetted out. Fortunately I was using slow hardener ( 35 min pot life but much longer once you spread it out and the heat generated by the curing does not speed the curing process up) and it was a cool night so it was still very workable. I was worried that it may have gone too viscous to effective squeeze out the excess resin but it did seem to be an issue based on the amount of resin that came out.

I used loads of paper towels as the breather/bleeder material and it works fine. In addition I used carpet felt underlay cut into strips and placed around the perimeter of the board to keep the air channel open so that the vacuum would be applied evenly around the board. This stuff works great.


Vac bag on and starting to evacuate it.....

..... evacuated and holding...

..... 27 inHg vacuum pressure.

Initially the vac pump engaged every 1-2 mins once it reached 27 inHg. I thin part of this is the lines in the pneumatic circuit distorting ( I'm only using fairly soft plastic hoses) and part was small leaks due to glass fibred draped across the tacky tap. I went around a pressed the film into the tape and also run a line of packing tape around the edges of the film. Because of the short duration of the starts the relay on the pump did not have time to reset properly and so the pump was not reengaging when the micro switch on my regulator closed but rather only when the relay on the pump reset. I was a bit worried about this but fortunately the seal got better and the restarts reduced to every 15-20 mins.

.... Next up a fuller debrief of what worked and what didn't....

Monday, December 5, 2011

Cores ready to laminate for board #3

Finally the cores are ready to laminate.
Life cycle of the core design...

The Paulownia cores are finally ready to rock.

The inserts and rails are cured and I've thinned the cores down from 12mm to about 10mm in the middle tapering to 8 at the end of the top deck and then 6mm constant thickness of the lower layer. I've also filled the insert holes with wax to prevent resin getting in (which is v. painful to remove afterwards).

I've got all the glass and graphics cut to size and now its just waiting on the rain to ease so I can start glassing.
The board 'kit' ready to roll.

Lay up schedule is going to be pretty basic:

+2 x 200 gm ( 6 oz) e-glass cloth top and bottom
+graphics encapsulated between 2 layers on bottom
+4 oz s-glass reinforcement under the foot pads
+R180 resin with slow hardener (to allow longer for excess resin to flow away)
+ White pigment in resin to seal the wood and provide the white background for the images on the underside
+ Seal the top with clear resin and let it yellow in the UV (for the antique wood finish)
+peel ply, paper towels (lots) for bleeder, breather material, proper 200 u vac bag. 25 mmHg vac.
+room temperature cure ( apparently R180 is designed for room temperate cure and doesn't benefit much from post curing. FGI's R300 series on the other hand requires it).
++ (new) glass both sides in the same session instead of one at a time.

Now just need the sun to come out and the rain to stop cause I'm working outside in the open car port and apparently moisture in the air weakens the resin. Although if its going to be under the vacuum film after 30 mins of wetting out then I am not sure how much opportunity there will be for it to absorb moisture.........

Thursday, December 1, 2011

Thinned the core and set inserts

I glued the core together but with the 11mm thick it was already very stiff so I shaved it down with an electric plane and 40 grit sandpaper on an orbital sander to get it to around 9-10mm. Cause the flexural rigidity is proportional to thickness cubed, a 10% reduction in the thickness leads to a 33% reduction in stiffness.
Next step was to add the inserts. I'm using just plain M6 stainless flange nuts. Last time I used these and pressed them into ABS plastic washers. The idea of the washer to spread the load around to reduce the stress at anyone point. However, after looking at the Decay boards, they used much small diameter holes to place the inserts into and so this time I going to use just the nut and rely on the smaller radius holes for the inserts to reduce the stress on the epoxy and hope that the 9-10mm core thickness gives enough area for it to stay put.
I had drilled the insert holes (20mm diameter) all the way through the board. I put a small amount of 5 min epoxy in the bottom of each insert hole to form the protective barrier to prevent too long screws pushing through the bottom of the board and delaminating it. The alternative is to cover the end of the nuts with metal ( this is how it is in most production boards I believe) so that the screw can't go through. This is obviously a more robust build but the unevenness of my core thickness was likely to make it necessary to chose a different screw length for each.
Tip: put masking tape over insert holes and then cut the hole out. This will stop the resin flowing onto the wood which takes time to sand back. I've also put some pigment in the resin and getting it on the wood stains it quite deeply.
To fix the inserts I place double sided tape on a piece balsa wood and pressed the head of the bolts ( the the nuts screwed on so that a couple of threads extended out the bottom) into the balsa. This made for a very simple support for the screws that could then be masking taped in place to keep them vertical and centered.
Next step is to actual start glassing. Got all the supplies I need from FGI. I also got a bit of a tour where then keep all the reinforcement they sell to walk-ins! After too'ing and fro'ing about s-glass and e-glass it ultimately came down to the availability of the right weights. So I've ended just going with 200gm woven e-glass, R180 resin and standard hardener ( 25 min working time).
Forecast for the next week is for rain so it looks like I may not get to finish the board in time for my trip to Old bar later this month. Shit!