You can do a heavy glass job with Epoxy too....

I have a 8'0 Prone Gun which weighs just under 6kg. I know some people are getting SUP's down towards that weight. The extra weight drives through chop a little better, and it is easier to keep the nose down when it is windy / off shore.

Glassed To Last, and triple stingers, all adds weight.

My favourite topic.

There is no question in my mind that for 'feel' a PU core feels better.

I rode PU for my first 3 years and changed over not too long ago. There are so many things I miss about the feel of those boards. It's the way the rail sits in the face when trimming and off the bottom. My next board, well I don't know anymore.

It's definitely better for bigger waves. C4 has just got DMS to make their big wave model in Australia in PU/Poly.

For my money if I was truly pursuing surfing performance on SUP I would be hassling Burford to blow me some very light PU blanks and glassing them in epoxy. Feel and strength with a light weight, the ultimate feeling..... Just expensive.

log man said...

CMC, Have you tried extruded polystyrene instead of expanded polystyrene?

Not on SUP but on shortboard.

It has a good feel but the issues and faults are many and varied. Difficult to machine, shape and most of all glass. The new ones with holes all through the glass to allow it breathe to avoid the impending delam are better but honestly why pay for a very expensive blank and glass job with about 7 extra production steps to get a board that feels like lively PU. It astounds me that people go to the moon and back adding all sorts of costs to boards with new materials etc to get boards that feel like what we already have.

I have met with composites suppliers on this and the technology available is amazing, it's just expensive. But why not just use PU and Epoxy? Many US Pro's now use this combo for shortboards as the trend is for added strength. Todays surfing places such demand on boards and it's so hard to find the 'magic' board that they want them to last. Even pro's who don't pay want a board that lasts long enough to win a heat.

log man said...

CMC, Have you tried extruded polystyrene instead of expanded polystyrene?

One more thing, I have never seen SUP Extruded blanks here on the Gold Coast, are they available where you are?

i am a light weight and love eps the lighter the better for me cant relate though for you big guys i was also like that for my shortboards always chasing that 2kg board!

CMC, Do Shapers have them in the "Super Xps" blanks . I just used Extruded insulation sheets. I got funny little bubbles in the lay up , but just continued on. I ended up reshaping the board later on and had to strip the glass of the blank, I dont know how this stuff would delaminate , it stuck together like...... you know... and an army.... yep

One question Brooko, Goaty et al.

Not condescending at all but how many PU's of different size and shape etc have you ridden to compare to your EPS? Most people just assume a SUP has to be EPS/Epoxy or from production boards EPS/PVC/EPOXY and have never even ridden a PU/Poly or PU/Epoxy.

I agree light is good, I am just not convinced that you can only achieve the weights you want with EPS/EPOXY. That's all. I know from my shortboards that PU boards with the same weights as EPS boards surf better and most people will agree with me. Just as we are finding out in other areas of this 'new' endeavour the lessons we have already learnt DO apply.

In answer to another q before it is asked. PU boards of the same weight as EPS boards do not surf the same.

dtm said...

cmc you are correct in saying that pu surf better its true but with the nature of sups being so thick and wide etc therefore to get a sup made from pu and still be strong weights a tone well a tone for myself is over 7kgs!!!! Mate if you can get a sub 7kg sup from pu i would love to ride it and would enjoy shaping it as eps suxz to shape glass sand etc. Im not comenting towards bigwave surfing here just average all round surfing where light is your friend.

I have ridden a couple of pu shortboards but not subs.

Who said you need a heavy board for solid waves A light sub goes great in solid waves. The lighter the better I reckon.

The 2 problems of extruded Polysyrene are the size of blanks you can easily buy 2400 X 75 X 800 is a standard from the Housing industry, and getting the epoxy resin to stick to it (the laminate can easily peel the "1st layer" of the core off) Whereas the Epoxy resin can go between the cells of Expanded polystyrene and keys into it for a stronger bond to the core.
I don't know if PU can get as light as PS,without core voids and shrinks in the future etc. It has suited the surfing industry that the glassjobs have got lighter and boards snap when there is a big wave on (as they get replaced by more of the same) Lats

OXMAN said...

is there any truth to poly being better suited to heavy riders (80kg+) on shorter boards even with an advance level of ability?

Hey Ox,

I am interested to know what do you mean by better?

Better performance?

Better longevity?

Is it for freesurfing or comp surfing?

What type of waves are you going to surf it in?

Better to repair?

I believe all these factors would effect the choice?

Regards

Phill

Hi Phil

My Question refered to performance

Cheers Ox

goatman said...

CMC said...

One question Brooko, Goaty et al.

Not condescending at all but how many PU's of different size and shape etc have you ridden to compare to your EPS? Most people just assume a SUP has to be EPS/Epoxy or from production boards EPS/PVC/EPOXY and have never even ridden a PU/Poly or PU/Epoxy.

I agree light is good, I am just not convinced that you can only achieve the weights you want with EPS/EPOXY. That's all. I know from my shortboards that PU boards with the same weights as EPS boards surf better and most people will agree with me. Just as we are finding out in other areas of this 'new' endeavour the lessons we have already learnt DO apply.

In answer to another q before it is asked. PU boards of the same weight as EPS boards do not surf the same.

So you have surfed 2 identical SUPs one PU and the other polystyrene core, to compare?

Unless there have been some serious advances in PU foam there is no way you will get a PU SUP with a volume of over 100 litres as light as an 'M' grade core polystyrene.

I be looking more to improve the designs than worrying about the the core.

I don't think you actually answered my question but in response to yours I would not say identical but very similar in dimension and from the same shaper. Close enough to feel and understand the difference. Have you ridden a light weight performance shaped PU??? Or did you start out on a EPS/PVC/EPOXY tanker and move on to custom EPS/Epoxy like most people?

My reference point here is that while we all think that lighter is better there is a point where I believe that a board will become so light that it will actually start to perform worse. I have stated before that I do not believe SUP design is unique in relation to other surfboards. The more I see the more I believe this.

The lessons learnt already are that when a board gets too light it loses momentum, has poor flex character and is generally not the feeling that you require. I am sure there will be boards made that reach that point. They will probably be overcome initially with very large fins to accomodate the fact that the rail will not hold in the water and to try to give some drive but ultimately these compromises are not desirable and slow the board down. On a small scale this happened with surftech.

dtm above says he was always chasing the 2kg shortboard. Mick Fanning will reject any board under 2.25 as you lose all feeling and momentum any lighter.

I do not think you can get PU to be the same weight as M Grade Polystyrene nor would you want to. What I am saying is that I believe that a lighter weight PU foam glassed in strong high grade cloth with epoxy would perform better overall than EPS/EPOXY. That is all, the weight will not be 6kg, but the hold, drive and flex of the board will be far superior.


I guess a disclaimer is timely here. I DO NOT sell PU Blanks for SUP.


p.s Lats, surfboard manufacturers are not protected with barriers to entry by AOCRA or SLSA licences and market price and request drives this scene.

Simondo said...

I still like the general idea of stringers for strength.

Bnaccas, 2 boards, different cores, same weight, easily achieved with different glass thicknesses / glass weight.

Poly Sailboards went like rockets IMO. Double stinger, running both sides of mast track, and both sides of fin box, was the answer. Nice and stiff.

My brother was saying that the chemicals is polyester resin are so bad, that they may be phased out.

All the research I've done says stringers in thick boards (over 3 1/2") are a waste of time. Once the preasure is enough to break the glass the stringer is already toast. The only reason the foam is there is to hold the top and bottom layers of glass apart. All the stregnth comes from the glass. This is different in very thin boards.

If you have to use different glass lay-ups to reduce weight then you are compromising strength. So therefore a PU board with the same glass job as an EPS board would end up being heavier due to the core weight.

And yep, I've heard a lot of manufacturers are going to PU/Epoxy instead of polyester due to health issues, more so in the USA.

OK....... I am working on something here. I think you'll all be very interested.

As scientific a test as can be done to discover the pros and cons of each kind of construction. I have mobilized half of the Gold Coast on this one.

More details to follow........ Stay tuned.

JB said...

You can always go done the timber vaneer route also. Great depression properties, and lots of strength at a lower weight than Epoxy. Naish have been using this for years in their sailboard technology, to keep the weight down, but increase the strength. They have been using it through their range of SUP from the start also. Bamboo seems to be used a lot these days.

JB

Already covered JB. I agree fully and this would be part of the tests. As I say more info to come soon.