In the process of making a super light wind float and ride board along the lines of the AHD sealion, and thinking of what glass/carbon etc to put under the 3mm pvc. The board is very unlikely to be jumped, even planing would be rare, except once on a wave.
I'd be interested to hear fellow board builders opinions.

As a basic start using glass,
One layer 4 oz over blank , pvc, 2 layers 4 oz on bottom ,patch around fin box . Top , 2 layers 4 oz all over , 1 layer from front of mast track back, 4 layers under foot pads.
That is a strong recipe for heavy me.
Id be interested to know what carbon lay ups I should use for my next board.
Please post pics as you go.

I'd prefer carbon under the footstraps rather than multi layers of glass, especially if you want it light.
What's needed there is stiffness not strength, same with finbox and mast track reinforcing. And I prefer it under the sandwich, that's the tension side, the top is in compression. But if you're heavy doing both wont hurt.

^^^ agreed

Additionally - glass under the pvc ensures adhesion as you wet it out first, just resin or just resin and filler would likely have areas of no adhesion.
But for this project a 2oz would be sufficient.

Def a layer of 6oz ish carbon in the stomp areas

On 1 pound eps for deck i use 4oz glass + 6oz biax carbon foot patch under sandwich, 6oz carbon biax over. I have friend that use 3oz and 5oz carbon for light slalom boards.

Why do we not use metric for these weights on this forum?

We do for foam density
just yanks lag there

interesting glass is almost always ounces due to us using surf products but I definitely think in gsm for carbon etc

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Mark _australia said..
We do for foam density
just yanks lag there

interesting glass is almost always ounces due to us using surf products but I definitely think in gsm for carbon etc

For surfing (in europe at least) everything is in feet, inches oz and lb, but windsurfing metric seems to be the only way to measure! so i'll be using a 15kg/m blank, 6 oz glass and 200g carbon! for balance sake i might measure my resin in pints!

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jontyh said..

Mark _australia said..
We do for foam density
just yanks lag there

interesting glass is almost always ounces due to us using surf products but I definitely think in gsm for carbon etc

For surfing (in europe at least) everything is in feet, inches oz and lb, but windsurfing metric seems to be the only way to measure! so i'll be using a 15kg/m blank, 6 oz glass and 200g carbon! for balance sake i might measure my resin in pints!

Sups and surfboards are feet , windsurfers are metric. Imperial measurement is spastic at best. Accurate inches morph into metric. One thousandth of an inch.Turns metric base 10 each number no matter how fine. You count in metric, why measure in another language ? I understand where feet and old weight came from ,it's relative to what you measure it against ,but why be so stubborn and still do it now ?
Why they haven't fixed it with time ? 10 hours a day , 100 minutes per hour , 100 seconds a minute and so on. They can measure so accurately now that we won't need leap years. Why do we have 24 segments in a day? And it's not that accurate. We could make it perfect in a simple way, just like counting.
It will happen.

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Shifu said..
Why do we not use metric for these weights on this forum?

Surfing/marine industry legacy... all other composite industries have moved on. Certainly the high end, prepreg type guys I've dealt with in the US all talk in gm/sqm, kg/sqm density and measure out resin in gm/kg.

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Imax1 said..

jontyh said..

Mark _australia said..
We do for foam density
just yanks lag there

interesting glass is almost always ounces due to us using surf products but I definitely think in gsm for carbon etc

For surfing (in europe at least) everything is in feet, inches oz and lb, but windsurfing metric seems to be the only way to measure! so i'll be using a 15kg/m blank, 6 oz glass and 200g carbon! for balance sake i might measure my resin in pints!

Sups and surfboards are feet , windsurfers are metric. Imperial measurement is spastic at best. Accurate inches morph into metric. One thousandth of an inch.Turns metric base 10 each number no matter how fine. You count in metric, why measure in another language ? I understand where feet and old weight came from ,it's relative to what you measure it against ,but why be so stubborn and still do it now ?
Why they haven't fixed it with time ? 10 hours a day , 100 minutes per hour , 100 seconds a minute and so on. They can measure so accurately now that we won't need leap years. Why do we have 24 segments in a day? And it's not that accurate. We could make it perfect in a simple way, just like counting.
It will happen.

I blame the UK and for lots else! (and i'm from the Uk) haha

IMAX it makes sense going back to the fathers of maths (was it babylonians?) who counted on their knuckles of fingers only, so it was base 12
12inches made sense many centuries later when it was already 60 mins, 12months, 360deg umm some other thing

still - yeah metric soooo easy. Nice to know 40thou to a millimeter working in engineering, cars and guns though

surfing is just legacy, wave height, board dimensions. Surfers are surprisingly conservative (or lazy). I think it's a reference thing, if you're always used to having imperial sized boards and waves, going metric involves mental arithmetic to compare to earlier boards and waves.
Windsurfers have always been metric though, so that's not a problem

I got my weight in kGs no problem but it's taken a while to convert my head to metric VS. I'm still 6' 7" tall with a 32" waist.

People using these forums for advice on what to use for a layup might appreciate metric measurment. The places I get cloth from list their products in metric only.

But it's an international forum, that's going to be hard to insist on.
From making boards in the 60s my head's quite happy with imperial. I've no idea what a 44galon drum of resin would be now.

So for workable cloth conversion, 135gm is 4oz, 200gm is 6oz.
Resin is normally sold in liters, so converting that to pounds is a two step process I don't have in my head.


Especially American pounds, I have a feeling US units are different to British, or is that only fluids.
It's all so complicated!
How can we force the rest of the World to go metric? \
Perhaps we need that one world government after all

It's really only the Americans that are the holdouts. Green = metric

WOW,
That is very surprising.
I'm sure Trump wouldn't help, can we have a word with Kamila?

Or new forum rule?
Can we have a vote?

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decrepit said..
WOW,
That is very surprising.
I'm sure Trump wouldn't help, can we have a word with Kamila?

Kamila would be all for it. She's a Californian after all... probably sails bump and jump.

Ok so for me for flatwater deck windsurf board on 16kg/m3 eps foam, i use 100 to 125g/m2 taffeta glass + 200g/m2 biaxial carbon foot patch under and 200g/m2 biaxial carbon over. Sometimes i add a thin 80 to 100gr/m2 taffeta glass over last carbon to protect it from sanding. I used 3mm 100 kg/m3 pvc foam first and know 2mm 170kg/m3 cork seal with light weight epoxy spackle. I use same build for deck of wingfoil and kite surf change foam density up to 30kg/m3 for jump use, i add stiffners in foam too.

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lemat said..
Ok so for me for flatwater deck windsurf board on 16kg/m3 eps foam, i use 100 to 125g/m2 taffeta glass + 200g/m2 biaxial carbon foot patch under and 200g/m2 biaxial carbon over. Sometimes i add a thin 80 to 100gr/m2 taffeta glass over last carbon to protect it from sanding. I used 3mm 100 kg/m3 pvc foam first and know 2mm 170kg/m3 cork seal with light weight epoxy spackle. I use same build for deck of wingfoil and kite surf change foam density up to 30kg/m3 for jump use, i add stiffners in foam too.

Are you using the cork insted of high density foam?

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Shifu said..

lemat said..
Ok so for me for flatwater deck windsurf board on 16kg/m3 eps foam, i use 100 to 125g/m2 taffeta glass + 200g/m2 biaxial carbon foot patch under and 200g/m2 biaxial carbon over. Sometimes i add a thin 80 to 100gr/m2 taffeta glass over last carbon to protect it from sanding. I used 3mm 100 kg/m3 pvc foam first and know 2mm 170kg/m3 cork seal with light weight epoxy spackle. I use same build for deck of wingfoil and kite surf change foam density up to 30kg/m3 for jump use, i add stiffners in foam too.

Are you using the cork insted of high density foam?

Yes it's agglomerate cork same characteristics than corecork (cork product specific for composit core). Build in a local factory cost at least 10x less than pvc core. Cork is heavier and can take lot of resin, but with right process give a really tough skin at good weight. Easy to work with. Work very well with carbon over.

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Mark _australia said..
IMAX it makes sense going back to the fathers of maths (was it babylonians?) who counted on their knuckles of fingers only, so it was base 12
12inches made sense many centuries later when it was already 60 mins, 12months, 360deg umm some other thing

still - yeah metric soooo easy. Nice to know 40thou to a millimeter working in engineering, cars and guns though

Guns are even worse. Using a gauge system for bullet diameters. A 20 gauge shotgun shell is smaller than a 12 gauge. They derived this system on how many balls of lead they can get out of a weight. If that's not whacko, I don't know what is. Why don't they just simply measure in diameter, even in inches if they have to ?

^^ Yeah but they shoot a certain weight (an ounce usually) of lead shot (balls)
So its the number of lead balls the size of the bore that makes up one pound. Perfect sense 12 lead balls that size is a pound.

Makes more sense than the new WA firearms laws that are fkn irksome to say the least don't get me started.,.....

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Mark _australia said..
^^ Yeah but they shoot a certain weight (an ounce usually) of lead shot (balls)
So its the number of lead balls the size of the bore that makes up one pound. Perfect sense 12 lead balls that size is a pound.

Makes more sense than the new WA firearms laws that are fkn irksome to say the least don't get me started.,.....

I hear what you're sayin.. However what if you want a light or heavy load of shot ?
Wouldnt it be easier if the bore was say three quarts of an inch and then determine how much powder and shot you want ? Like a long or short bullet ? I ve used 22 long and short. 20 to almost 40 mm long from memory. Father in law owned a gun range. Lucky I never got shot , showing up on a two stroke dirt bike trying to take her away.