I am just about to put an order in for some Black Project WEEDspeed fins, I have never used weed fins before and need to know if they are comparable in terms of size choice to normal slalom fins?
The pic on the site (blackprojecthawaii.com/ scroll down, the page isnt updated yet though) shows more area, especially at the base so I am guessing slightly smaller fin on the same sail.

I need them for the BSA slalom and know you guys use them a lot on your lakes. I will have sails from 8.8 - 8.0 - 7.3 - 6.6 - 6.0 - 5.5(dont think I will race in slalom for my first season if its 5.5 weather though!). The fins come in sizes 42,38,34,31,28. Ideally I only want to get 2, so which 2, but if I have to stretch to 3 then which 3. I have a full quiver of slalom and near full quiver of speed fins, but have read reports from previous years where the earlier events are plagued with weed.........

Thanks in advance

If you want them for slalom rather than speed then you will need to go bigger as the crosswind performance of a weedy is considerably less than a pointer unless well powered up and slower to accelerate out of the gybe. If I were going for two with those size sails I would go 42 ( for 8.8, 8 and a big board) and 31 (for 7.3, 6,6 and might be a bit big for 6 / 5.5 but I am assuming you are talking ocean rather than flat water).
The Mandurah mob started with 36 and 31 JP weedies which cover most conditions but they don't use as big sails as you.
Personally I have used a 40 Leading Edge weedy with a 122 iso and Loft Blade 7m and found it a good fin up to about 18 knots. All my other weedies are smaller with my 24 a favourite on 6.3 and less for speed sailing on flat water.
If you can go 3 fins 42,34,28 IMO

I was thinking 42,38,34.....but that makes total sense, thanks.

The sizes they have given the Black Project Weed Speed fins relate to what they reckon would perform the same as the equivalent size Type R so in theory select the fins based on what size Type R fins you would be using. They are looking into creating some smaller ones maybe a 25 and a 22 for speed boards.

They look nice, but I'm not sure, they seem like straight G10 to me.
The shorter fins may be OK, but unless they are quite thick, longer weedies need carbon in them to be stiff enough.

Select to expand quote

decrepit said...

They look nice, but I'm not sure, they seem like straight G10 to me.
The shorter fins may be OK, but unless they are quite thick, longer weedies need carbon in them to be stiff enough.

All Black Project fins are G-10 I am not aware of any stiffness problems with them. From my experience G-10 is the best material for making fins.

I got Black Projects to make me a weed fin about 12 months ago stating that the percentage along the flow line needed to be about 9 to 10. However the fin came back too flexy for my liking. It was around 9 percent, but not along the flow line. More like along the flow line if the fin was upright, then canted over to 40 degrees. Attached is the original drawing supplied to them around this time last year, seems to me that they thought it might work.

I should have started with "now don't get me started". This is the same fin after more than 10 hours work on it... Because the fin was too flexy, the only solution I could come up with was to laminate carbon on to it. Introducing Mr hacksaw and Mr belt sander, a couple of mates of mine. Not a cheap solution! (timewise and cost). But the fin is now fast and rigid. Also able to withstand a fair amount of abuse.

I've needed to do this to my larger fins only as the smaller ones are inherantly more rigid. (the smaller you go the more rigid etc)
Here's a test, go out and grab your favourite weed fin, bend it over your knee and see how much flex it has....defence rests your honour.

No wind for a week now, who else can I go crook at? [}:)]

Select to expand quote

pepe47 said...

No wind for a week now, who else can I go crook at? [}:)]

I will try and flex the WEEDSpeed 42 over my knee but I have a strange feeling it will not have much flex in the body.

Select to expand quote

legless said...

decrepit said...

They look nice, but I'm not sure, they seem like straight G10 to me.
The shorter fins may be OK, but unless they are quite thick, longer weedies need carbon in them to be stiff enough.

All Black Project fins are G-10 I am not aware of any stiffness problems with them. From my experience G-10 is the best material for making fins.

The leverage on larger weed fins creates quite a bit of flex if using only G10. This increases drag and reduces lift.

Legless after reading Pepes post I take it you are now aware of flex in larger sizes.

Perhaps you should have also mentioned that you are the Australian importer for Black Project fins.

Select to expand quote

yoyo said...

legless said...

decrepit said...

They look nice, but I'm not sure, they seem like straight G10 to me.
The shorter fins may be OK, but unless they are quite thick, longer weedies need carbon in them to be stiff enough.

All Black Project fins are G-10 I am not aware of any stiffness problems with them. From my experience G-10 is the best material for making fins.

The leverage on larger weed fins creates quite a bit of flex if using only G10. This increases drag and reduces lift.

Legless after reading Pepes post I take it you are now aware of flex in larger sizes.

Perhaps you should have also mentioned that you are the Australian importer for Black Project fins.

YoYo my comments on G-10 fins come from my 30 years of windsurfing experience I was not being specific about Black Project fins and this thread was not started by me. redsufbus asked about which fin sizes to buy as the info about the WEED Speed is not yet up on the Web site and I have a picture of the 31 - 42 WEED Speed fins I decided to post it to help redsurfbus out.....but I guess you like most people just like to see the worst in everyone.

Select to expand quote

legless said...

pepe47 said...

No wind for a week now, who else can I go crook at? [}:)]

I will try and flex the WEEDSpeed 42 over my knee but I have a strange feeling it will not have much flex in the body.

I've found that even if you have flex at the tip it's enough to cause spin-out when it's loaded up fully. We're talking about up wind in chop etc.
I doubt that it will have much flex in the body but try the tip and see how it is..
When the tip flexes it's angle of flex is no longer along the flow line. It is on a pointer, which will not directly affect it's performance, even enhance it in some cases, but with a weedie..

Select to expand quote

pepe47 said...

legless said...

pepe47 said...

No wind for a week now, who else can I go crook at? [}:)]

I will try and flex the WEEDSpeed 42 over my knee but I have a strange feeling it will not have much flex in the body.

I've found that even if you have flex at the tip it's enough to cause spin-out when it's loaded up fully. We're talking about up wind in chop etc.
I doubt that it will have much flex in the body but try the tip and see how it is..
When the tip flexes it's angle of flex is no longer along the flow line. It is on a pointer, which will not directly affect it's performance, even enhance it in some cases, but with a weedie..

I will check to see how much flex they have....but as you say it depends were the flex is as to how it will affect the fin or not as you say and I have found in the past a bit of flex in the tip of a pointer helps performance so I guess it will come down to how black projects have designed the flex in the tip of the fin.

.....but I guess you like most people just like to see the worst in everyone.

??????

The topic was about weed fins. I was commenting on that. As noted here by yourself and others tip flex on pointers is not a bad thing but but not really relevant. My other comment was just a suggestion not a critism and I'm a bit surprised you took it so personally. I think most people would like to know if someone offering an opinion about something has a vested interest in that something.

Select to expand quote

yoyo said...

.....but I guess you like most people just like to see the worst in everyone.

??????

The topic was about weed fins. I was commenting on that. As noted here by yourself and others tip flex on pointers is not a bad thing but but not really relevant. My other comment was just a suggestion not a critism and I'm a bit surprised you took it so personally. I think most people would like to know if someone offering an opinion about something has a vested interest in that something.

Yoyo as I said I was refer to all G10 fins not being specific about Black Projects I have no vested interest, redsurfbus is in the UK and most likely buying his fins direct from Black Projects. I was trying to be help him out, anyone else that jumps into the conversation like yourself is just jumping to conclusions and reading into something that is not there........that is seeing the worst in everyone.....maybe you should be honest with yourself before offering an opinion on others motives with you are only making assumptions about and getting it wrong.

Thanks to all of you, no need for argument allthough I can understand why people get defensive nowadays after recieving some flack myself for 'pimping'.

Most windsurfers will help each other, obviously some will have a vested interest in certain brands, either through plain old brand loyalty from personal choice, or through trying to make a living in this world where everyone has got used to getting things for free. I feel lucky that I chose to change my quiver over to Black Projects back in October after testing some Exocets that came with a quiver of type R's. It wasnt until christmas day that I recieved an invite to become a team rider (second best Christmas present! Best was a Neil Pryde race bag :-D), I had already bought a half quiver by then. I know Legless is the importer over there, as he has been very helpful in the past and told me this in other threads. Shops over here wont stock specialist fins, the only slalom you will find are the odd drake and maybe a prolimit slalom-esque style fin so I guess its a similar situation over there, everyone needs to try their best to make a living, and some importers choose their products for a good reson, they believe in them!

I need them for the slalom series (not that it will make much of a difference, I have never raced before!), and I suspect I wont use the 42 very often. I like the idea of getting the 42 34 28 which allows me to trial them across the range. I am lucky at my home spot that we hardly ever get weed, and where we do often its too shallow to risk sailing over, as it is full of rocks as well. The only bad time for weed here is in the mid spring when a lot of the old weed detatches from the rocks up in a lagoon that floods into the harbour. So I will either go for the 3 as stated or maybe just the 38 - 31 and save a bit of money for now.

Thanks for all your help.

I think it should also be noted there are different grades of G10, I cannot tell you the specifics but I learned this from a certain West Aussie speedsailor also well known for his fin design and making. My attempts at googling G10 do not yield many results of value.

I have two different 46cm weedys from two different fin makers with Maui in their name and one is a LOT stiffer than the other one and when standing up against me and my 8.6 the stiffer one performs far better.

Select to expand quote

legless said...

[b]>>>>
All Black Project fins are G-10 I am not aware of any stiffness problems with them. From my experience G-10 is the best material for making fins.

G 10 is great for upright fins, strong,with good abrasive qualities. And if you want a flexi tip it doesn't have to be thinned down too much.

BUT a flexi weedy is close to useless!!! (The greater the rake the worse the effect of flex becomes)

If a G10 fin uses the full length of the base and has a thickness to flow ratio around 9%, it will probably be OK to a bit over 30cm. (I haven't had much to do with fins bigger than this, you'd have to ask Pepe or Bender).

My test is to put the weedy over my knee and try to bend it, if you can flex it more than a few mm it needs carbon to stiffen it up

Select to expand quote

decrepit said...

legless said...

[b]>>>>
All Black Project fins are G-10 I am not aware of any stiffness problems with them. From my experience G-10 is the best material for making fins.

G 10 is great for upright fins, strong,with good abrasive qualities. And if you want a flexi tip it doesn't have to be thinned down too much.

BUT a flexi weedy is close to useless!!! (The greater the rake the worse the effect of flex becomes)

If a G10 fin uses the full length of the base and has a thickness to flow ratio around 9%, it will probably be OK to a bit over 30cm. (I haven't had much to do with fins bigger than this, you'd have to ask Pepe or Bender).

My test is to put the weedy over my knee and try to bend it, if you can flex it more than a few mm it needs carbon to stiffen it up

I will check the flex as you suggest of the 42 WEED Speed tomorrow however the last time I looked at it, it felt like a very stiff fin it has a thicker foil like the Type R as compared to the Type S which is a thinner fin.

Select to expand quote

redsurfbus said...

I am just about to put an order in for some Black Project WEEDspeed fins, I have never used weed fins before and need to know if they are comparable in terms of size choice to normal slalom fins?
The pic on the site (blackprojecthawaii.com/ scroll down, the page isnt updated yet though) shows more area, especially at the base so I am guessing slightly smaller fin on the same sail.

I need them for the BSA slalom and know you guys use them a lot on your lakes. I will have sails from 8.8 - 8.0 - 7.3 - 6.6 - 6.0 - 5.5(dont think I will race in slalom for my first season if its 5.5 weather though!). The fins come in sizes 42,38,34,31,28. Ideally I only want to get 2, so which 2, but if I have to stretch to 3 then which 3. I have a full quiver of slalom and near full quiver of speed fins, but have read reports from previous years where the earlier events are plagued with weed.........

Thanks in advance

RedSurfBus have you got your WEED Speed fins yet? If you have how did they go?

We havent had any wind since I posted that, have you seen where the Portland Pirates are this month on the GTC? Worst month since I joined. I also havent got the Weed fins yet

Select to expand quote

redsurfbus said...

We havent had any wind since I posted that, have you seen where the Portland Pirates are this month on the GTC? Worst month since I joined. I also havent got the Weed fins yet

Sorry to hear that we did not get any wind this weekend here either. Dan was using the WEED Speed 31 and 28 at Sandy point this week end: gpsteamchallenge.com.au/sailor_session/show?date=2012-03-24&team=48

Yes the trouble is that when a weedie flexes it loses angle of attack towards
the tip. An upright fin can flex without losing angle of attack. I think I've even read that they can bias the fibres in some upright formula fins such that they increase angle of attack with flex.

I've got a couple of Select weedies. They had all the issues you hear about in weedies, but with one and a third layers of carbon they are much, much better.

I worried that if the layer of carbon stopped abruptly at the base there would be localised discontinuity of flex and not the maximum stiffness. So when I laminated with carbon I routed channels in each side of the base so a supplementary pair of 40 mm carbon strips could run continuously from the wide section of the foil into the base. I then back-filled the base to it's original shape.

I spent a lot of time thinking about the best angle of laying the fibres so that there would be a twist within the remaining flex that would minimise loss of angle of attack at the tip. I couldn't get my head around a solution so just ran the fibres straight down the fin's long axis.

Sounds about right Ian, I normally remove all the base around the thickest part of the fin, (that's where the load is). Running the uni slightly from the back of the fin at the base to the front of the fin at the tip will allow the fin to flex off, from the front of the fin at the base to the back of the fin at the tip will cause it to flex on.
This is probably what you want with a weedy, (my head can no longer do dynamic 3d modelling,. Just bent a bit of card at 45deg, and flexing on, is the go), but overdoing it would lead to instability.
Must give it a go next time I carbon a weedy.

Select to expand quote

legless said...
Dan was using the WEED Speed 31 and 28 at Sandy point this week end: gpsteamchallenge.com.au/sailor_session/show?date=2012-03-24&team=48

Sure did, I was very impressed with both of them.

Felt solid up and across the wind and really nice off the wind down the strip. Quick too, only 0.5 slower than Jacques and 2 slower than Kato who got his speeds on a his CA SP40 when I was on a slalom board. However those two fins are the smallest 2 sizes at 24 & 27cm deep so no flex issues there. Can't comment on the bigger sizes.

Will definitely keep using them, am getting myself ready for an end of year LG trip... As I reckon most of GPSTC will be

Select to expand quote

BundyBear said...

I think it should also be noted there are different grades of G10, I cannot tell you the specifics but I learned this from a certain West Aussie speedsailor also well known for his fin design and making. My attempts at googling G10 do not yield many results of value.

I have two different 46cm weedys from two different fin makers with Maui in their name and one is a LOT stiffer than the other one and when standing up against me and my 8.6 the stiffer one performs far better.

G10 itself is a grade of Epoxy laminates, there's also G5-G9, G11.
so really the specs between the different suppliers shouldn't change that much.
maybe we should ask for the a Material datasheet with each fin we purchase.

some specs here

http://cctplastics.com/cnc-plastic-machining-materials/cnc-materials-G5-G9
cctplastics.com/cnc-plastic-machining-materials/cnc-materials-G10

Select to expand quote

vando said...

G10 itself is a grade of Epoxy laminates, there's also G5-G9, G11.
so really the specs between the different suppliers shouldn't change that much.
maybe we should ask for the a Material datasheet with each fin we purchase.

"G10" from China could mean any "panel" containing traces of "fiberglass". So many variables to control to meet the proper spec. There is a mil spec grade but nobody is using it because its a lot more expensive. Theres G10, then theres "G10" which most windsurfing fins are made from these days.