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tarquin1 said..
>>>>
I also have a question about trimming the airex stage. I am building a SUP, OK its not a windsurfer but a board build is a board build. I want to put airex on the bottom of the board and wrap it up around the rails. I see in the pic he has just put too wide a piece of airex and trimmed it back. Has he put tape or something so it doesnt stick or do you just sand it back.
What density foam is the blank and what pressure is he using when bagging. Is he using epoxy to glue the high density foam to the blank.
OK that was more than a question.

Where are you getting airex from????

It's much tougher than divinycell and miles easier to form 3d curves, but a bit softer, the surface is more likely to dent.

I haven't been able to find any here. The last lot I used was imported from New Zealand about 20 year ago.

Boards are usually built with the rails wrapped from the top not the bottom, it's a much softer curve.
I normally stick the bottom sandwich on with 4oz glass wetted out on the bench, before the rails are shaped, then the rails gets shaped into bottom high density foam. The top high density foam then wraps all the way round the rails, with as you saw a bit of excess. Taping the bottom out can make cutting the excess of easier, but I normally don't bother, if you can do it just after the resin sets, it's easy enough to slice a sharp knife through the excess.
I've no idea what Fred is doing but blank density is normally 13 to 16kg/m2 And yes epoxy is the go

It's just high density foam. 2mm 55kg. I am in France and Airex is available here. It's a lot more expensive.
The deck is going to be wood done last. So I want to put high density foam on the bottom and rails first. I will do some experiments heating the foam and forming it. It is a CNC cut blank. So the shaping is done.
Thanks.

55kg is very light for a PVC / SAN foam used in board building and I don't know that we can get that here in Aust. I'd be interested to know what it is, do you have pics / link / brand and model number? Would be perfect for a SUP as you don't need to go up to 80kg foam like windsurf boards.

Given it is thinner and lighter, about 10" HG would be plenty of vac. I didn't realise you did not shape it...... as you don't have a template I guess, make sure you put a LOT of time making a perfect rocker spine, else it will bend in the bag.
Make sure you measure the rail ruck really well all the way along, say every 200mm, as the top lam will bend around the rails but be a little inconsistent in where it butts up against the bottom lam...... so there will be a little reshape required after bagging the top on. Most of that reshaping will be along where the rail tuck meets the bottom. Arguably, the most important area too.

Hang on I just realised ..... you are not going to put hi density foam on the deck is that right....?

I will start a new post in the SUP section. Dont want to hijack this one. Please check in and keep the info coming.

I feel so spoilt with 2 of my designs being built at the moment. Fred is progressing and the fin boxes are in. What an awesome job he is doing.

Big midsection patch....? (or uneven colour that happens with resin tinting on occasion...?)

Not sure Mark

The layup is what Fred has developed and uses and I am unsure if I am allowed to make it public. There is a layer of 80gsm Spread Tow carbon between the straps and mast box in this layup, the area that gets a pounding from chop so I am guessing that is what it is. Discoloration may be micro bead filler?? He still has more carbon to go on around the fin boxes . The top layer will be SX glass that I sent him from here. The bottom is painted white but the deck will be exposed carbon so assume he uses clear filler where needed on that.
I leave the layups to the experts and take their advice..every builder has a diferent take on it. My only specification on this one was to substitute some carbon on the bottom with S glass as I didn't want the harshness of full carbon.

Mast box and vent in....

One question and I know it's been mentioned before on this forum but why put the vent plug there? In the tail seems like a better place so you can stand it on end if water gets in and it will run out.

I like it near the mastbox as it is in my face when I mount the uni so I never forget to screw it up.

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Mark _australia said..
I wanna know how he builds a carbon mast track

This is a way to do it...translate.google.com/translate?hl=nl&sl=fr&tl=en&u=http%3A%2F%2Fguidedupetitshapeur.1fr1.net%2Ft429-boitier-de-pied-de-mat-en-carbon-par-infusion

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Ben1973 said..
One question and I know it's been mentioned before on this forum but why put the vent plug there? In the tail seems like a better place so you can stand it on end if water gets in and it will run out.

Like Mr Love said

But also, its not a drain hole. If have damage at the nose and stand it on the tail, the water will never reach there. You will have half a litre spread out from nose to tail, unless you want to stand it for 3 years...

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watermonster said..

Mark _australia said..
I wanna know how he builds a carbon mast track

This is a way to do it...translate.google.com/translate?hl=nl&sl=fr&tl=en&u=http%3A%2F%2Fguidedupetitshapeur.1fr1.net%2Ft429-boitier-de-pied-de-mat-en-carbon-par-infusion

He is not really saying how he is using the screws to pull the plug out - that's easy with something really thick and strong but would easily break a box.

I'd run with dissolvable / melting wax plug I think.

OTOH the weight at dead centre of the board is not something I worry about. Now, 4 plastic fin boxes vs 4 carbon slots - that is worth it.
My slots are 80gm.

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watermonster said..

Mark _australia said..
I wanna know how he builds a carbon mast track

This is a way to do it...translate.google.com/translate?hl=nl&sl=fr&tl=en&u=http%3A%2F%2Fguidedupetitshapeur.1fr1.net%2Ft429-boitier-de-pied-de-mat-en-carbon-par-infusion

132gr for a Chinook mast track

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Mark _australia said..

Ben1973 said..
One question and I know it's been mentioned before on this forum but why put the vent plug there? In the tail seems like a better place so you can stand it on end if water gets in and it will run out.

Like Mr Love said

But also, its not a drain hole. If have damage at the nose and stand it on the tail, the water will never reach there. You will have half a litre spread out from nose to tail, unless you want to stand it for 3 years...

Guess that answers the question.

Yes it is still happening...was always a "just fit it in when you can" build Fred has the final layer on the bottom, Shapers SX Glass I sent him from here. Now the finishing starts!!!

Sexy or what.....

Looks awesome

Oooh. Niiiiice!!

Getting closer....I think it is going to be too schmick to use.
Nice!!!!

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mr love said..
Getting closer....I think it is going to be too schmick to use.
Nice!!!!

Is that double concave all the way to the end or does it go flat v?
Or has it a funky single concave in the middle then flat v thing going on ?

ps; it's ok , looked at page one , double concave all the way .
Whats it for, rough bay water ?
Lastly , what's the box head done with the stringers , what exactly is done there ? , ...... it's ok , I can say that .
Nobody else can say that because it would be offensive.
..........
crickets ...........

Aussie with German parents and a humor gland ....boom!
Last beer , promise ,
,..........,
Again , Boom! ,!

Still enjoying retirement honeymoon .
How many extra kgs is acceptable before I got to get my ****e together ?

Double concave right through with V side panels. Concave in the tail is subtle. Has some spiral V in the tail. High wind Port Phillip Bay board, hopefully nice to my old Knees. Bottom is not full carbon, S Glass and carbon to soften the ride a bit. Its the SX glass from Shapers that is meant to be the ducks guts.
I did not get too involved in the construction, let Fred do his thing as he has built lots of boards. I just push curves around a computer screen. Those slots in the bottom of the foam when milled are for stringers but I don't know the details of what he did.

I am not sure I want to sail it...looks too good.

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mr love said..
Double concave right through with V side panels. Concave in the tail is subtle. Has some spiral V in the tail. High wind Port Phillip Bay board, hopefully nice to my old Knees. Bottom is not full carbon, S Glass and carbon to soften the ride a bit. Its the SX glass from Shapers that is meant to be the ducks guts.
I did not get too involved in the construction, let Fred do his thing as he has built lots of boards. I just push curves around a computer screen. Those slots in the bottom of the foam when milled are for stringers but I don't know the details of what he did.

I am not sure I want to sail it...looks too good.

Its beautiful...the man is a master craftsman.

"Double concave right through with V side panels."? Wot kind of dog eees this???

Spiral V????

You're a lucky man getting him to use that spread-tow carbon.
Its a mongrel to work with
Very nice board

Do I see accommodation for three footstraps with four bolts each (two per side)? Nice! (Four-bolt footstraps should be mandatory on all boards. The two-bolt ones I have on my JP boards are honestly their weakest feature.)

Oh I love the deck top with only clear-coat on carbon. The look suits the shape. Slippery A.F., probably, but put pads below the footstraps for grip and just don't step out of the straps, ever, and you're golden.

Never used it Mark....Freds choice but it looks like he knows what he is doing.

Spiral V...Fancy name for the V increasing towards the tail, or the nose.

V side flats......the concave is parallel so at the outboard side you are left with a flat V panel

Yep 4 screws per strap. don't need adjustment as this board if for yours truly.

It will have non slip over that beautiful carbon.

Nice board
Mr Love it's great to see your design work almost finished.
Yes the clear carbon deck looks awesome and you just have to ride it

I thought spiral V is produced at the tail of a board with a constant parallell double concave . When the narrowing end of the board has less and less of the original concave left , leaving a half concaved V at midpoint of the concave and getting less ,closer to the tail .
So when this happens your affectively creating an increasing V.
Apposed to having a complete concave in the V out the back .
Kinda like the flared front part of a boat that spirally twists the wake out of the way as it's pushing through the water .( there's got to be a name for it , other than the bow ) .?
But in reverse.
Spiraling out the back ?

On my board the actual V angle increases into the tail from 400 off, pretty subtle but it is there. What you are saying about the rail lifting as the the board narrows is true until it gets to the deepest part of the concave then as the board narrows more to centerlinie it actually does the opposite and climbs down the concave so you sort of get a S in the rail in side view.
You cant change the amount of V unless you actually change the V angle itself.