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decrepit said...

Does sound like moving the straps back will help.
As yoyo has mentioned, I put my boxes further forward than normal, as I'm always using weedys

I guess you mean the fin further forward on the board or box further backwards on the fin ?

I install the box further forward in the board. (normally a box is about 80mm from the back of the board, I put mine 90mm to 100mm from back of board).
Then when I box a weed fin I set it to the front of the base. When I box a more upright fin I set it further back in the base.
That way I don't have to have the leading or trailing edges outside the base.

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decrepit said...

I install the box further forward in the board. (normally a box is about 80mm from the back of the board, I put mine 90mm to 100mm from back of board).
Then when I box a weed fin I set it to the front of the base. When I box a more upright fin I set it further back in the base.
That way I don't have to have the leading or trailing edges outside the base.

OK, I don't do my own boards yet :-)
I have no problem moving the LE in front of box on my production boads.
Depends on the size. How big weed fins do you make ?

What happened to the Trim Box ?

Cheers
Rasmus

Hi Rasmus,

a profile with the thickest point further forward does not significantly move the COE forward. it will still be very close to 25% from the leading edge with most "normal" sections.

moving the straps and mast foot back helps a bit, but on larger weed fins there is not really any other solution than moving the fin forward either on the base or moving the whole box. on larger slalom boards it might even be worth installing a second box in front of the old one and use a plug to cover the box that is not used.

Boogie

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C3 said...

Hi Rasmus,

a profile with the thickest point further forward does not significantly move the COE forward. it will still be very close to 25% from the leading edge with most "normal" sections.

moving the straps and mast foot back helps a bit, but on larger weed fins there is not really any other solution than moving the fin forward either on the base or moving the whole box. on larger slalom boards it might even be worth installing a second box in front of the old one and use a plug to cover the box that is not used.

Boogie

Hi Boogie

I came out with the same conclusion about the quart chord after calculating some profiles.

My intention was also to move the fin as much forward as possible on the big fins (>30 cm).

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RasmusDK said...
>>>>>
Depends on the size. How big weed fins do you make ?

>>>>
Cheers
Rasmus

My biggest so far is 31cm, but most of them are under 26cm.

I make most of my fins from timber and carbon, but also reshape bigger G10 fins when I get them.

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decrepit said...
My biggest so far is 31cm, but most of them are under 26cm.

I make most of my fins from timber and carbon, but also reshape bigger G10 fins when I get them.

Ok, It's also above 32 cm where the problems really starts to become serious
Anyway, it bet that with your boards and weed fins you never feel it's a weedy

finally got some wind for testing not much mind but overall happy apart from the catapult and 2 broken battens LOL... fun day

2 more fins on the way to be re boxed

Nice vid Leo and love the dismount. Looked fairly innocuous - surprised you broke some battens.

Bloody hell

you stuck a stack of Carbon fibre on your face

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elmo said...

Bloody hell

you stuck a stack of Carbon fibre on your face

yeh i dont think you wetted it out enough. Next time use more resin

Great looking video as always, good to see you were able to get out and test a creation at last, you looked happy with it.

lol I thought it was funny at first then i looked at the sail ;-( not what i needed

If i don't put the music over it U can hear them snaP!!

r well was a fun day !

I was thinking i could of put my 7.5 up n jumped on the CA44 would you guys say

that a 22 weedie would hold ?

so exited i get my DRAKE back from the reboxer this week time to START the

ITCHING!!

re boxed a couple of slalom fins, took a mould of the slingshot both sides at an angle between the slingshot and 45deg, the grey fin has notched up 32nts in 15to 20 on a 5/8 n/p rs, the black fin is an old us box slalom 33 laminated with 4 layers of 2oz carbon and 2 layers of 3oz satin weave and polyester resin hopeing the angle is ok for weed

NICE ONE KEEF !! THEY LOOK THE GOODS CANT WAIT TO CATCH UP !!

CANT BELIVE I MISSED YA THE OTHER DAY U SHOULD OF SAID U WERE THINKING OF COMING UP ... NEXT TIME PM ME OR CALL 0403902721

leo i sent you a text sending you a PM passed my mind but i thought i could find the place

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keef said...

leo i sent you a text sending you a PM passed my mind but i thought i could find the place

never got he text strange next time ;-)

Does anyone know if you can buy G10 material in a sheet around 16mm thick
And what grade is suitable for fins?
Thanx

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ducati said...

Does anyone know if you can buy G10 material in a sheet around 16mm thick
And what grade is suitable for fins?
Thanx

hard to find ducati thats why "i hear" that KA fins take so long to get... they cant get hold of the quality .

I had a look around but I'm not that savy on G10 that i would Buy a few hundred dollers worth to find out its not what u want

but all this talk on fins is making Certain manufactures take notice for sure have a look at the new deltas I've sailed the 25 and was super solid I also have 21 but no wind !!

I spent today epoxy / glassing a tuttle box into a broken slot box Speed Slolom Board. Ready for when I rebox some old fins, I picked up some moulding silicon ready for the job. Will post up the reboxed weed fin when I get it done.
While I getting out some glass out of storage I found an old Invoice
1 Lineal Meter Unidirectional Carbon cloth $13.15 Oct 1989 what do you pay now?
I was putting carbon fibre in my fins back then

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ducati said...

Does anyone know if you can buy G10 material in a sheet around 16mm thick
And what grade is suitable for fins?
Thanx

Sheet of g10 @16mm will cost a small fortune!
I buy 1/2 sheets of thinner g10, then laminate 2 sheets together to build the thickness up. Thou laminating the sheets together is little difficult as air bubbles can be trapped between the laminates, thus can be overcome by laminating small area @ a time using heat & pressure.
There is no problem with the sheets de-laminating from each other as the epoxy glues we use are bullet proof, the actual fibers in the G10 ripped before the epoxy glues let go.

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ducati said...

Does anyone know if you can buy G10 material in a sheet around 16mm thick
And what grade is suitable for fins?
Thanx

WHY G10 i don't know to much about resins G10 is a high heat resistant epoxy resin they use in circuit boards with glass fiber, so i can understand why they use it for fins
epoxy resin is extremely hard to shape and sand and that's a good reason to use it for fins so it stops everyone from making there own fins
epoxy has high memory and flex, vinylester has less, and polyester less again, vinylester&polyester is much easyer to sand but the trade off it's heavier
vinylester is the way to go but only buy the quantity you need because its wax promoted so it has a low shelf life
vinylester&polyester have a high flammability rating so be careful if your hoping for 50knts you melt the back of your board

i can't see a problem with icesurf's method as long as it has been sanded before laminateing, the only problem i can see is the shaping, I'm sure most of the G10 fins today are moulded or lathed

keef, I thought g10 was fibreglass laminated with epoxy, then put under 10 tons of pressure (I guess that's per square inch) to maximise fibre to resin content.
That's why the stuff is so strong and tough, with no voids.
It's the preference here as it doesn't wear as fast in our gritty weed.

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decrepit said...

keef, I thought g10 was fibreglass laminated with epoxy, then put under 10 tons of pressure (I guess that's per square inch) to maximise fibre to resin content.
That's why the stuff is so strong and tough, with no voids.
It's the preference here as it doesn't wear as fast in our gritty weed.

decrepit i don't think us backyarders can make a product like G10 but we can come close, here's a slab of vinylester i knocked up years ago, it has about 20 layers of glass ,kevlar in the center and chop as a filler,from memory i laid it up in between 2 pieces of waxed melamine and used about 1% or less catalyst then used g clamps for compression
the problem you have with that sort of layup on a big slab is ,as your laying up its creating heat and starting to cure before you can clamp it down, even with say .75 of catalyst,if that slab had the same amount of layers of glass and some carbon it wouldn't be far behind the G10 but wouldnt be a light as the G10
[/b]

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It's the preference here as it doesn't wear as fast in our gritty weed.

the vinyl ester is very scratch friendly and fgi have a 2 part glue RO45&HO45 it has texture of marjoine so easy to apply and extremely hard to sand

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keef said...

decrepit said...

keef, I thought g10 was fibreglass laminated with epoxy, then put under 10 tons of pressure (I guess that's per square inch) to maximise fibre to resin content.
That's why the stuff is so strong and tough, with no voids.
It's the preference here as it doesn't wear as fast in our gritty weed.

decrepit i don't think us backyarders can make a product like G10 but we can come close, here's a slab of vinylester i knocked up years ago, it has about 20 layers of glass ,kevlar in the center and chop as a filler,from memory i laid it up in between 2 pieces of waxed melamine and used about 1% or less catalyst then used g clamps for compression
the problem you have with that sort of layup on a big slab is ,as your laying up its creating heat and starting to cure before you can clamp it down, even with say .75 of catalyst,if that slab had the same amount of layers of glass and some carbon it wouldn't be far behind the G10 but wouldnt be a light as the G10
[/b]

It's the preference here as it doesn't wear as fast in our gritty weed.

the vinyl ester is very scratch friendly and fgi have a 2 part glue RO45&HO45 it has texture of margarine so easy to apply and extremely hard to sand

Finally got round to taking a photo of my 2 weed fin's cira 1989 they are both up for reboxing to tuttle & will report in when I try them. The white'ish one is quite thin about 7.5/8 mm Raked at 25 deg then, 40.5 deg, 255 deep. The black one is 12/13 m thick. That one I made for a race board for extra lift when beating up wind. I also moulded it, layed up the glass & carbon on both sides poured expanding urathane foam in the center (to reduce weight) & clamped the 2 halves together. Start rake 34deg then standing up to 43deg 275 deep

Is this thread still going just sail where there isn;t any weed guys

unfortunately chocco we have to sail were there is weed to get flat water there are very few spots that hold good speeds in NSW so the search is on for the fastest weed fin

THE NEW ONE SAILED IT YESTERDAY GOT A **** LOAD OF LIFT FROM IT !

I even put my mast track forward 3 inch !! just to flatten it down wen i did this it felt and "apparently" looked real good i was also able to close the gap more comfortably and felt solid upwind and down for a 21 cm, I'm sure i will be able to sail the 7.5m on it as it was so solid with the 6.7m and Ca44

happy camper come on wind !! good fit too decrepid .. on to the next one let the itching begin ..wife not happy

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choco said...

Is this thread still going just sail where there isn;t any weed guys

It's almost going as long as the Loft Blade 2011 gear review, which is due to finish in late 2012