I peeled the hydroturf off in front of the track expecting to see some cracks but the skin seems ok.

I can get access via the inspection port I installed. Thinking of attempting to glass in some timber stringers inside hull top and bottom and try and fix some timber dowl between them to strengthen the area.

Any better ideas are welcome

Serious bummer.

Well, you know everything is fixable right.

I'd be looking hard to find out exactly what is going on before coming up with a rescue plan. Even if that means getting more (temporary) access inside the board. Happy to offer what I can at that stage.

p.s. That is a fine looking sail. I'm quite partial to the all white style.

If the core is the issue, will the frames help significantly?

I don't know your board. Do you want it to be beautiful, or just to work - and for how long? I think there's a variety of treatments, from the bodge job that will get it going for a while all the way to the "better than new" repair.

Select to expand quote

saltyheaven said..
Serious bummer.

Well, you know everything is fixable right.

I'd be looking hard to find out exactly what is going on before coming up with a rescue plan. Even if that means getting more (temporary) access inside the board. Happy to offer what I can at that stage.

p.s. That is a fine looking sail. I'm quite partial to the all white style.

I will try and get some photos of the inside with my phone. I have reasonable access already with a port I cut earlier to allow me to bolt in a new mast track.

The sail is a Barracouta 9.5mtr custom that I picked up with an old F2 lightning a couple of years ago. I have been saving it to use with the D2 and yesterday was the first day I have ever used it. Its Dacron/mylar in basically new condition and has 4 full battens and one half batten across to the window and no cams. very lightweight. I ended up using it on my raceboard after I brought the D2 in and it performed pretty well, the westerly kicked in and was gusting up to 20kns and the sail was still quite manageable

Select to expand quote

Chris 249 said..
If the core is the issue, will the frames help significantly?

I don't know your board. Do you want it to be beautiful, or just to work - and for how long? I think there's a variety of treatments, from the bodge job that will get it going for a while all the way to the "better than new" repair.

I like to go for decent sails, often by myself. I want the board to last and I want it to be reliable. The problem with older boards is they often show their weaknesses in the worst possible moments. I want to be confident I can trust it to get me home should I get caught out in conditions that will place some stresses on the gear.

Failed laminate in front of the track with a crack running down port side of the track.

I can access ok, maybe enough to sand and glass over


Back of the centreboard case looks dodgy, I could see light coming through from the flash, It had a fair bit of water in after a very brief sail I suspect that where its entering



Another crunchy spot right at the back next to the port I cut to remount the fin box. I have enough access to sand and glass over i think.




Seeking thoughts on the best course of action

Select to expand quote

saltyheaven said..
Hi longandheavy,

1. I wouldn't worry about the 'slot'. If it happens naturally that's fine and if not that is fine too.
2. I have no experience with formula sails but due to their weight alone I would not put them on top of any list of desirable D2 sails. A 7.5 or 8.5 raceboard sail would be my choice, tight leech.
3. Leave your centreboard all the way down to encourage railing upwind. Tip the board back a touch if the railing gets too much. Big fins seem to me counter to the whole D2 concept, if you want to plane off the fin maybe a raceboard is a better choice.
4. You want to ride with the nose up in the air? I'm imagining that photo is a moment of rising up, bouncing if you like, from a trim that averages somewhat lower. Flat is fast. The Lechner a390 nose does ride reasonably high when fully powered up going downwind, but to artificially encourage it up is just inviting drag.
5. I think mast track position is more about fore and aft board trim than anything else and to my mind that usually means as far forward as can be, consistent with the need for keeping the nose from stuffing into waves. In light winds I would run forward on all points. In really light wind headed upwind, in the middle so as to have the rig balanced and light in my hands rather than held awkwardly tipped back, feet either side of the mast. To get to the very back of the track would take a solid 20+ knots and a decent chop, heading on a broad reach. Straight downwind in the same conditions I'd actually slip the track forward a touch and continuously try to edge my weight, and feet, forwards too. Fast and slippery, on the edge and a whole lot of fun!

Good luck!

Hi saltyheaven, thanks very much for comments. Agree fully with most of said, just remarks to some points :)
2) I have very old V8-9.0 (which is said to be more DII suitable and lighter than pure racing fully cambered sail) similar to be seen in action on Eric s DII video. Ive tested both V8 and Vapour (same size) with Lechner and don't feel much difference. As mentioned yet, I am heavyweight = need MORE power, comfort sacrificed. Sails of A and B types are NICE and I have them still both in garage. I just wanted a little upgrade, DII used to be racing beasts :) and so are nowadays race sails.
Anyway. I'll forget about 10.7 RS evo and I'll go on testing my 7,5m2 old Equippe "B sail" and 9m2 "C sails" V8 ...and Vapour.

3) clear.. centreboard slightly back only when railing too much. I don't suppose to "ride the fin" just wanted to push lateral center more back. C type 9.0 sails are bigger than probably designers originally in eighties intended... and my 41cm fin is not "big" on todays terms. But I'll test smaller fin as well.

4) "flat is fast" and hull length is core DII advantage. But even displacement Lechner starts to glide /afraid to call it planing/ somehow and sometime. Then nose up and lower wetted area are reality.. and DRAG unfortunately. It looks fast and scary. It is hard to evaluate such speed without gps, but I hope it is higher then theoretical threshold of displacement speed /cc 5kts?/. I've not found DII speed records, but if yes (?), than sometimes worth riding nose up ..if we survive it.. and even if lightwind boards were not intended for such use/mode.
Interesting for me is another of your remarks: "really light wind upwind > track in the middle + feet either side of the mast = the rig balanced and light in hands rather than held awkwardly tipped back". I shall try it next time.
Good wind and a lot of fun with rounded hulls...

Never any D2 boards here in US, but an Alpha Phantom showed up not far away - appears to he the one with the scooped rear deck. No daggerboard (but could make one of course). Can anyone comment on it's light wind performance? And it's weight?

Select to expand quote

longandheavy said..

saltyheaven said..
Hi longandheavy,

1. I wouldn't worry about the 'slot'. If it happens naturally that's fine and if not that is fine too.
2. I have no experience with formula sails but due to their weight alone I would not put them on top of any list of desirable D2 sails. A 7.5 or 8.5 raceboard sail would be my choice, tight leech.
3. Leave your centreboard all the way down to encourage railing upwind. Tip the board back a touch if the railing gets too much. Big fins seem to me counter to the whole D2 concept, if you want to plane off the fin maybe a raceboard is a better choice.
4. You want to ride with the nose up in the air? I'm imagining that photo is a moment of rising up, bouncing if you like, from a trim that averages somewhat lower. Flat is fast. The Lechner a390 nose does ride reasonably high when fully powered up going downwind, but to artificially encourage it up is just inviting drag.
5. I think mast track position is more about fore and aft board trim than anything else and to my mind that usually means as far forward as can be, consistent with the need for keeping the nose from stuffing into waves. In light winds I would run forward on all points. In really light wind headed upwind, in the middle so as to have the rig balanced and light in my hands rather than held awkwardly tipped back, feet either side of the mast. To get to the very back of the track would take a solid 20+ knots and a decent chop, heading on a broad reach. Straight downwind in the same conditions I'd actually slip the track forward a touch and continuously try to edge my weight, and feet, forwards too. Fast and slippery, on the edge and a whole lot of fun!

Good luck!

Hi saltyheaven, thanks very much for comments. Agree fully with most of said, just remarks to some points :)
2) I have very old V8-9.0 (which is said to be more DII suitable and lighter than pure racing fully cambered sail) similar to be seen in action on Eric s DII video. Ive tested both V8 and Vapour (same size) with Lechner and don't feel much difference. As mentioned yet, I am heavyweight = need MORE power, comfort sacrificed. Sails of A and B types are NICE and I have them still both in garage. I just wanted a little upgrade, DII used to be racing beasts :) and so are nowadays race sails.
Anyway. I'll forget about 10.7 RS evo and I'll go on testing my 7,5m2 old Equippe "B sail" and 9m2 "C sails" V8 ...and Vapour.

3) clear.. centreboard slightly back only when railing too much. I don't suppose to "ride the fin" just wanted to push lateral center more back. C type 9.0 sails are bigger than probably designers originally in eighties intended... and my 41cm fin is not "big" on todays terms. But I'll test smaller fin as well.

4) "flat is fast" and hull length is core DII advantage. But even displacement Lechner starts to glide /afraid to call it planing/ somehow and sometime. Then nose up and lower wetted area are reality.. and DRAG unfortunately. It looks fast and scary. It is hard to evaluate such speed without gps, but I hope it is higher then theoretical threshold of displacement speed /cc 5kts?/. I've not found DII speed records, but if yes (?), than sometimes worth riding nose up ..if we survive it.. and even if lightwind boards were not intended for such use/mode.
Interesting for me is another of your remarks: "really light wind upwind > track in the middle + feet either side of the mast = the rig balanced and light in hands rather than held awkwardly tipped back". I shall try it next time.
Good wind and a lot of fun with rounded hulls...

Cool, and no worries. It's clear that you understand well what I've written and have a handle on the balance and drag concepts. Maybe your preferences will end up being a bit different to mine. You'll feel it when it's right. Have fun!!

Hmmm, I was thinking about a V8 as well but maybe the 8.0sqM.

I don't have a need to be at warp speed all the time. I sailed Formula class but didn't like the heavy feel of the full cam race sails. Almost pulling a shoulder socket trying to pump the cams through.

I reckon the D2 is a finesse board. Sure you can put a huge engine into a Mini Moke and go fast, but that's not what they're supposed to be used for.

I'm with Mikey on this one, just having a fun sail for 0 - 15 knots. One board, one sail.

Select to expand quote

longandheavy said..

saltyheaven said..
Hi longandheavy,

1. I wouldn't worry about the 'slot'. If it happens naturally that's fine and if not that is fine too.
2. I have no experience with formula sails but due to their weight alone I would not put them on top of any list of desirable D2 sails. A 7.5 or 8.5 raceboard sail would be my choice, tight leech.
3. Leave your centreboard all the way down to encourage railing upwind. Tip the board back a touch if the railing gets too much. Big fins seem to me counter to the whole D2 concept, if you want to plane off the fin maybe a raceboard is a better choice.
4. You want to ride with the nose up in the air? I'm imagining that photo is a moment of rising up, bouncing if you like, from a trim that averages somewhat lower. Flat is fast. The Lechner a390 nose does ride reasonably high when fully powered up going downwind, but to artificially encourage it up is just inviting drag.
5. I think mast track position is more about fore and aft board trim than anything else and to my mind that usually means as far forward as can be, consistent with the need for keeping the nose from stuffing into waves. In light winds I would run forward on all points. In really light wind headed upwind, in the middle so as to have the rig balanced and light in my hands rather than held awkwardly tipped back, feet either side of the mast. To get to the very back of the track would take a solid 20+ knots and a decent chop, heading on a broad reach. Straight downwind in the same conditions I'd actually slip the track forward a touch and continuously try to edge my weight, and feet, forwards too. Fast and slippery, on the edge and a whole lot of fun!

Good luck!

Hi saltyheaven, thanks very much for comments. Agree fully with most of said, just remarks to some points :)
2) I have very old V8-9.0 (which is said to be more DII suitable and lighter than pure racing fully cambered sail) similar to be seen in action on Eric s DII video. Ive tested both V8 and Vapour (same size) with Lechner and don't feel much difference. As mentioned yet, I am heavyweight = need MORE power, comfort sacrificed. Sails of A and B types are NICE and I have them still both in garage. I just wanted a little upgrade, DII used to be racing beasts :) and so are nowadays race sails.
Anyway. I'll forget about 10.7 RS evo and I'll go on testing my 7,5m2 old Equippe "B sail" and 9m2 "C sails" V8 ...and Vapour.

3) clear.. centreboard slightly back only when railing too much. I don't suppose to "ride the fin" just wanted to push lateral center more back. C type 9.0 sails are bigger than probably designers originally in eighties intended... and my 41cm fin is not "big" on todays terms. But I'll test smaller fin as well.

4) "flat is fast" and hull length is core DII advantage. But even displacement Lechner starts to glide /afraid to call it planing/ somehow and sometime. Then nose up and lower wetted area are reality.. and DRAG unfortunately. It looks fast and scary. It is hard to evaluate such speed without gps, but I hope it is higher then theoretical threshold of displacement speed /cc 5kts?/. I've not found DII speed records, but if yes (?), than sometimes worth riding nose up ..if we survive it.. and even if lightwind boards were not intended for such use/mode.
Interesting for me is another of your remarks: "really light wind upwind > track in the middle + feet either side of the mast = the rig balanced and light in hands rather than held awkwardly tipped back". I shall try it next time.
Good wind and a lot of fun with rounded hulls...

The D2s weren't really "lightwind boards" as such. They are "all wind boards" and other boards of the time were either slower designs, or specialist high-wind boards. In the early days of pro "funboard" racing we had a lower wind limit of 15 knots, which soon dropped to 12 knots. So the "funboards" were the high wind boards and the "all wind boards" were D2s. The D2s were used in strong winds as well as light winds. At a guess, they'd have to be able to reach 18 knots - the theoretical threshold of displacement speed does not apply in such slender and light hulls.

I think you're completely right about designers not thinking of 9m sails - everyone just thought about class legal sails when designing the boards, as far as I can see.

Flat's not fast on longboards upwind. Hull length doesn't seem to be all that critical in D2s. Lechner also designed the TC Win, which was my first D2. It had a much shorter sailing length than the Lechner A390, but the Lechner A390 was faster despite the extra rocker. Sure, in boats length is enormously important, and even in Raceboards, but I suspect the greater volume of D2s is creating some unusual effects. I think they are semi-planing quite early on and therefore length is not such an issue.

I'd agree with Jethrow's post. D2s are more about finesse. I'm happy with a 7.3 - one board, one sail, zero to 22+ knots, although I can recall one regatta where I used a 5.6 and was the only finisher in one race. Fun times!

Here's a thought, a hollow, full carbon D2 with a Severne Hyperglide........

3 layers of glass over the damaged in front of the mast track, same again in the damaged area in front of the fin box. I cant get the air bubbles out no matter how I try. Basically working by feel then taking photos to try and see whats happening.


I am thinking of glassing in this bit of foam after the above sets to strengthen the area.

Would that be helpful, harmful or just a waste of time and serve no real purpose??

Select to expand quote

cammd said..

3 layers of glass over the damaged in front of the mast track, same again in the damaged area in front of the fin box. I cant get the air bubbles out no matter how I try. Basically working by feel then taking photos to try and see whats happening.


I am thinking of glassing in this bit of foam after the above sets to strengthen the area.

Would that be helpful, harmful or just a waste of time and serve no real purpose??

Thumbs Up !! You could stagger the edges of the new glass next time but reckon what you've done is fine.

Strip of foam to be glued to the inner skin and then glassed over? Like a kind of short stringer thing? Sounds good to me.

Another thing that comes to mind is to look at how the rigid strength of the mast track area transfers to the relatively flexible hull skin immediately in front of it and try to make that transition gradual over an area rather than sudden. You could do the same with your foam stringer, feather the tips before glassing over, and stagger any glass that laps onto the hull.

You'll be on the water again before you know it.

Yeah, the strip of foam glued to the new repair will add minimal strength but even a single layer of decent glass over the foam to make a foam filled tunnel will provide stiffness and it can be tapered towards the end to avoid a hard spot.

I was thinking of running the foam stringer across the hull over the centre of the damaged area but now I am thinking two stringers starting either side of the mast track and running forward and tapered and installed as advised. That should address the transition from rigid mast track area to more flexible deck whilst supporting the damaged area at the same time. As always seeking thoughts.

Yeah id run the stringers next to and parallel to the mast box and under damaged area and tapering both ends.
On a totally different tangent , what about very lightly box up , ( super thin shirt box type plastic ) ,under the weak area to the bottom hull and fill with expanda foam in a can , it would be super strong , lighter than glassing , cost $7 from Bunnings .????? It would however stuff up access for future repairs.

Select to expand quote

Chris 249 said..

longandheavy said..

saltyheaven said..
Hi longandheavy,

1. I wouldn't worry about the 'slot'. If it happens naturally that's fine and if not that is fine too.
2. I have no experience with formula sails but due to their weight alone I would not put them on top of any list of desirable D2 sails. A 7.5 or 8.5 raceboard sail would be my choice, tight leech.
3. Leave your centreboard all the way down to encourage railing upwind. Tip the board back a touch if the railing gets too much. Big fins seem to me counter to the whole D2 concept, if you want to plane off the fin maybe a raceboard is a better choice.
4. You want to ride with the nose up in the air? I'm imagining that photo is a moment of rising up, bouncing if you like, from a trim that averages somewhat lower. Flat is fast. The Lechner a390 nose does ride reasonably high when fully powered up going downwind, but to artificially encourage it up is just inviting drag.
5. I think mast track position is more about fore and aft board trim than anything else and to my mind that usually means as far forward as can be, consistent with the need for keeping the nose from stuffing into waves. In light winds I would run forward on all points. In really light wind headed upwind, in the middle so as to have the rig balanced and light in my hands rather than held awkwardly tipped back, feet either side of the mast. To get to the very back of the track would take a solid 20+ knots and a decent chop, heading on a broad reach. Straight downwind in the same conditions I'd actually slip the track forward a touch and continuously try to edge my weight, and feet, forwards too. Fast and slippery, on the edge and a whole lot of fun!

Good luck!

Hi saltyheaven, thanks very much for comments. Agree fully with most of said, just remarks to some points :)
2) I have very old V8-9.0 (which is said to be more DII suitable and lighter than pure racing fully cambered sail) similar to be seen in action on Eric s DII video. Ive tested both V8 and Vapour (same size) with Lechner and don't feel much difference. As mentioned yet, I am heavyweight = need MORE power, comfort sacrificed. Sails of A and B types are NICE and I have them still both in garage. I just wanted a little upgrade, DII used to be racing beasts :) and so are nowadays race sails.
Anyway. I'll forget about 10.7 RS evo and I'll go on testing my 7,5m2 old Equippe "B sail" and 9m2 "C sails" V8 ...and Vapour.

3) clear.. centreboard slightly back only when railing too much. I don't suppose to "ride the fin" just wanted to push lateral center more back. C type 9.0 sails are bigger than probably designers originally in eighties intended... and my 41cm fin is not "big" on todays terms. But I'll test smaller fin as well.

4) "flat is fast" and hull length is core DII advantage. But even displacement Lechner starts to glide /afraid to call it planing/ somehow and sometime. Then nose up and lower wetted area are reality.. and DRAG unfortunately. It looks fast and scary. It is hard to evaluate such speed without gps, but I hope it is higher then theoretical threshold of displacement speed /cc 5kts?/. I've not found DII speed records, but if yes (?), than sometimes worth riding nose up ..if we survive it.. and even if lightwind boards were not intended for such use/mode.
Interesting for me is another of your remarks: "really light wind upwind > track in the middle + feet either side of the mast = the rig balanced and light in hands rather than held awkwardly tipped back". I shall try it next time.
Good wind and a lot of fun with rounded hulls...

The D2s weren't really "lightwind boards" as such. They are "all wind boards" and other boards of the time were either slower designs, or specialist high-wind boards. In the early days of pro "funboard" racing we had a lower wind limit of 15 knots, which soon dropped to 12 knots. So the "funboards" were the high wind boards and the "all wind boards" were D2s. The D2s were used in strong winds as well as light winds. At a guess, they'd have to be able to reach 18 knots - the theoretical threshold of displacement speed does not apply in such slender and light hulls.

I think you're completely right about designers not thinking of 9m sails - everyone just thought about class legal sails when designing the boards, as far as I can see.

Flat's not fast on longboards upwind. Hull length doesn't seem to be all that critical in D2s. Lechner also designed the TC Win, which was my first D2. It had a much shorter sailing length than the Lechner A390, but the Lechner A390 was faster despite the extra rocker. Sure, in boats length is enormously important, and even in Raceboards, but I suspect the greater volume of D2s is creating some unusual effects. I think they are semi-planing quite early on and therefore length is not such an issue.

I'd agree with Jethrow's post. D2s are more about finesse. I'm happy with a 7.3 - one board, one sail, zero to 22+ knots, although I can recall one regatta where I used a 5.6 and was the only finisher in one race. Fun times!

Hi DII fans, thanks for comments concerning DII "upgrade" (bigger sails, technique). We /on this site/ agree that:
-D2 is the best equipment from 0 to Xkts (individually 15..20..22 :)
- it was in 80ties precisely factory designed and tuned for sails 6.5/long booms.
- a lot of us prefere "original" ONE sail for all conditions, rather smooth, easy going operation in lower wind range at least.

BUT.. there are some who believe that...
DII hulls (at least later 80ties designs) can be pushed faster with help of modern sails /fins? maybe. So once more specific topic/question:

if I put 9m2 sail instead of original 6,5m2
is the original fin still optimal?

Similar discussions occurred for OLD raceboards /NO wide tails, but used often with sails bigger, then in eighties originally intended (google f.ex. "long raceboard fins why? Raceboard fin size, What size fin for a raceboard).
And conclusions are even there NOT clear at all!!!
Some argue that fin over 29cms slows, some recommend up to 39/43cm / all agree that sizes are limited by fragile US boxes. For heavy weight riders and bigger sails probably slightly bigger fin on RB helps /?/.
I know concepts are different, but as Chris wrote and we sure agree that "semi-planing mode" is reality and important part of DII sensation.
Any experience with fin sizes for 9m2 sails welcomed...

I agree with the tapering/staggering of the glass edges, and also stringers that feather out at their ends.

Also, I think it is important that the repair goes around from the flat and onto the curved edge to create a dome like structure. It is the flats that are the worst at supporting load (compared to a convex surface)

I have a bit of work to do on a M1 as my next project- I was thinking of cutting the board along the edge seam, doing all the work from the inside- then gluing the two halves back together.

I reckon you should get a D2 Imax- you could even take your cat for a sail on it.

Clarence

^^^
I had one a crit

Longandheavy, on Speed 250 RB ive tried many fins. Changed finboxes from US to PB as i had PB fins. For strong winds a 38cm fin works fine in US box. Ive run up to 44cm with no issues. Finding a fin in US box is the issue. However on light wind days 9.5m sails n PB board it really makes a difference to be able to use fins around 50cm. Gets planing when previously 'no chance'. Does however make the board stiff to turn. But all im interested in is straight line speed. Ive found 45-50cm JP SUPERSPORT fins work well on the ol SPEED 250.

Select to expand quote

olskool said..
Longandheavy, on Speed 250 RB ive tried many fins. Changed finboxes from US to PB as i had PB fins. For strong winds a 38cm fin works fine in US box. Ive run up to 44cm with no issues. Finding a fin in US box is the issue. However on light wind days 9.5m sails n PB board it really makes a difference to be able to use fins around 50cm. Gets planing when previously 'no chance'. Does however make the board stiff to turn. But all im interested in is straight line speed. Ive found 45-50cm JP SUPERSPORT fins work well on the ol SPEED 250.

Olskool, thanks for comment... RB's fins have been discussed on more specialised forums /bigger probably helps, even on old "narrow" FUNboards/ planing.
BUT there is some mystery (for me) in semi-planing mode of DII. As I estimate roughly from brochures - original Lechner3 - 84 /narrow/ fin looks about 20cm and L390 about 25cms /+slightly wider yet/? can owners of original boards measure and correct me?/.
As I look on nice :) board of Cammd, above on this page.. I estimate 40cms, upright race fin. So? makes difference? I am not speaking about extremes, My Lechner shape has PB, for which I have choice in range between max. 41cm freerace... and as opposite tiny 15cm hooked oldschool...

This is the fin I got with the board, was used at the Anchor Beers IBSA World Boardsailing Championships in Singapore by KA-250 (anyone know who that was).

The one on the board now is a 38cm race fin, hard to find a fin with a US box so big (thanks DaVecta). I don't know what difference it will make, but being 95kg I like to use 9.5mtr sails so I thought a bigger fin would be better plus I think it looks better. I have Speed Formula One RB that next on the resto list so the fin may find it's way to that board in due course.

I think this fin is originally is off a Lechner like my centreboard but not really sure

As a slight diversion, I saw this on Facebook and thought some here might enjoy it!

Old school D2ing

As a Lechner A390 owner from August 1989 & other D2s from a few years previous I'd like to confirm/ comment on past posts made.
First, that picture posted by cammd is indeed the latest model one design fin, measuring 280mm in depth. It replaced the earlier 230mm fin in late 1990, early 1991 to align with the adoption of the Neil Pryde 7.3m2 one design rig. The 'new' fin has approximately 22% greater surface area. The attached photo is of that earlier model fin.

The one design rig was a total package of mast, boom & cambered sail. It was used in the 1992 Barcelona Olympics, whereas in the 1988 Seoul Olympics a 6.5m2 North (soft old style) triangular mylar sail was used.

In regard to using fins greater that the originals be warned. The way the US box is integrated into the hull layup isn't structurally strong & even the latest 280mm fin created overflex & cracking issues. The lateral loads are quite high when reaching in strong winds. Reinforcing the area requires one the perform major 'open heart' type surgery. Not for the faint hearted !

Another note of caution relates to comments made about 'leak finding' using a vacuum cleaner. If the board doesn't leak applying that much pressure will lead to possible hull separation issues. Minor leaks can be easily found using soapy water & a few mouth breaths of pressure. You will quickly see bubbles appearing from those leaks. Anything larger than those minor cracks will most probably see any internal water flowing out, simply via gravity. Rotate & tilt to see the drips or water flows . I can only see a vacuum cleaner being used as a 'dry out' measure, nothing more.

All my boards have a coiled plastic tube breather pipe installed in the front access porthole. The board then pressure adjusts itself 24/7. That tube is then used to apply mouth pressure when checking for leaks. It is worth checking the rubber porthole washers making sure a tight seal is obtained when screwed back in.

The last attached photo shows off the difference between the earlier 87 / 88 boards used in Seoul & the last models produced that moved the centreboard & mast track back approximately 90 / 100mm. There also appears a slight change in the footstrap setup.

I found this old Mistral M1 D2 while riding my bike through Nudgee Beach recently. Don't get too excited, all the bolt on bits looked like they were designed for fishing. I remember the centreboard on these boards was a work of art.
Maybe the old 16 ' skiff is worth getting though?

Select to expand quote

robhow2 said..
As a Lechner A390 owner from August 1989 & other D2s from a few years previous I'd like to confirm/ comment on past posts made.
First, that picture posted by cammd is indeed the latest model one design fin, measuring 280mm in depth. It replaced the earlier 230mm fin in late 1990, early 1991 to align with the adoption of the Neil Pryde 7.3m2 one design rig. The 'new' fin has approximately 22% greater surface area. The attached photo is of that earlier model fin.

The one design rig was a total package of mast, boom & cambered sail. It was used in the 1992 Barcelona Olympics, whereas in the 1988 Seoul Olympics a 6.5m2 North (soft old style) triangular mylar sail was used.

In regard to using fins greater that the originals be warned. The way the US box is integrated into the hull layup isn't structurally strong & even the latest 280mm fin created overflex & cracking issues. The lateral loads are quite high when reaching in strong winds. Reinforcing the area requires one the perform major 'open heart' type surgery. Not for the faint hearted !

Another note of caution relates to comments made about 'leak finding' using a vacuum cleaner. If the board doesn't leak applying that much pressure will lead to possible hull separation issues. Minor leaks can be easily found using soapy water & a few mouth breaths of pressure. You will quickly see bubbles appearing from those leaks. Anything larger than those minor cracks will most probably see any internal water flowing out, simply via gravity. Rotate & tilt to see the drips or water flows . I can only see a vacuum cleaner being used as a 'dry out' measure, nothing more.

All my boards have a coiled plastic tube breather pipe installed in the front access porthole. The board then pressure adjusts itself 24/7. That tube is then used to apply mouth pressure when checking for leaks. It is worth checking the rubber porthole washers making sure a tight seal is obtained when screwed back in.

The last attached photo shows off the difference between the earlier 87 / 88 boards used in Seoul & the last models produced that moved the centreboard & mast track back approximately 90 / 100mm. There also appears a slight change in the footstrap setup.

robhow2 thank you for very precise description :)
That CB and footstraps move 10cms backwards confirms (probably) that semi-planing mode was rather important for late D2s.
Can you confirm following positions for updaded/last Lechner - measurements from board front tip to:
Mast track most Forward axis - 170cm?
Mast track most Backwards axis - 220cm?
CB pivot /rotation axis - 250cm? Thank you in advance :)

what does Lechner 390 mast foot look like ??
especially the part that attaches to the the track bus

Information & photos for L & H and Joe's queries.

1700mm to front track car centre; 440mm front car centre to rear most centre of track car.
2375mm front tip of board to 1st centreboard slot (centre of). 2nd rear most slot a further 75mm back.
Note 99.99% of the time sailing with the 7.3m2 sail & smaller I use the rear centreboard slot. The front position never seems to have the same balanced setup once on the rail sailing upwind. From memory all AUS racers used this location for the centreboard. The mast track is again 99.99% of the time at the very front for upwind sailing in all breezes. On my old IMCO One Design I found that the mast track can provide a better balanced setup, set back to 2 - 3 for upwind in the lighter range of winds. So similar sail sizes but different outcomes board to board.

The mast foot pin measures 25mm O/A in length (main body) & has a diameter of 13.85mm. Odd size, but it is what it is ! The white plastic washer sits on the track car.

you have all those pins ??
i may have found a Lechner with all parts except the mast foot
sent Eric an e-mail about it too ...