If I had the loose screw problem I would use loctite blue the day before.
But I have an AFS Wind95 and mast/fuse is a one piece T.

Select to expand quote

boardsurfr said..

Heavy1 said..
I'm quite heavy at 130 kg, and I love the infinity 99 which gets me up in the light stuff much like the lighter guys, for about 15 to 20 minutes, then the bolts snap.

If you are using a board with tracks (or can get one to try), one possible solution would be to use the "A" position instead of the B position. The A position aligns the mast and the upward push of the front wing much better, which should reduce the stress on the bolts quite dramatically. I have had problems with bolts getting loose in sessions, but fortunately they never snapped. I'm using 316 stainless steel bolts rather than the original titanium bolts.

I think the Slingshot problems can be understood looking at the history of their foils. The original foils were for kiting, where the A position is used. When they expanded to windsurfing and made boards with tuttle boxes, they had to move the wings more forward, and ended up drilling a couple of holes into the fuse. A pragmatic solution that works ok for many lighter foilers, but is quite limited in the amount of load it can take. Other companies like Starboard or Fanatic that designed the windfoil wings from scratch ended up with designs that are mechanically more sound.

Totally agree with the "A" position idea but either the lift is too far back or the mast just feels too far forward and to weird to get going. I guess I could learn to cope, but it doesn't feel right . Im hoping my work around is a solution. If the bolts hold up well I will smooth it all up nicely and report back. I think siingshot gear is great. This problem has just sort of evolved, but yes that 2018 flanged carbon mast looks perfect too. There must have been a problem there, ??? what a great idea but why didn't it follow through.

That anodized fuse with flange looks perfect too.

I must admit to trying to make my own fuse and failing badly due to crappy aluminum . I over built the thickness to cope with lesser aluminum but it bent like butter. There are some crazy forces acting on these components.

Select to expand quote

Sandman1221 said..
If I had the loose screw problem I would use loctite blue the day before.
But I have an AFS Wind95 and mast/fuse is a one piece T.

Personally I think the mast crushes at the mast to fuse interface. That then starts wiggling the bolts. Even a locked tight bolt will still eventually fatigue and stretch a bit. Thats why in my case of pushing the limits locking the bolts with lock tight or plumbers tape doesnt work , and makes a much harder repair when the bolts do snap.
Thankfully I picked up the reverse drill thread idea.

Select to expand quote

Heavy1 said..

Personally I think the mast crushes at the mast to fuse interface. That then starts wiggling the bolts. Even a locked tight bolt will still eventually fatigue and stretch a bit. Thats why in my case of pushing the limits locking the bolts with lock tight or plumbers tape doesnt work , and makes a much harder repair when the bolts do snap.
Thankfully I picked up the reverse drill thread idea.

Does it return to flat when disassembled? Are you a hard carver? That can add 30% to your weight loading. The local slingshot riders around here carve hard, way over 100kg of loading at times i'd think. It only lasts for a second but they do a lot of them. What do you torque the bolts to? Maybe A bit more pre-load, pre-stretch on the bolts could help reduce play once under way.

Breaching one wing first is probably the hardest on the fuse to strut connection.

Select to expand quote

Ian K said..

Heavy1 said..

Personally I think the mast crushes at the mast to fuse interface. That then starts wiggling the bolts. Even a locked tight bolt will still eventually fatigue and stretch a bit. Thats why in my case of pushing the limits locking the bolts with lock tight or plumbers tape doesnt work , and makes a much harder repair when the bolts do snap.
Thankfully I picked up the reverse drill thread idea.

Does it return to flat when disassembled? Are you a hard carver? That can add 30% to your weight loading. The local slingshot riders around here carve hard, way over 100kg of loading at times i'd think. It only lasts for a second but they do a lot of them. What do you torque the bolts to? Maybe A bit more pre-load, pre-stretch on the bolts could help reduce play once under way.

Breaching one wing first is probably the hardest on the fuse to strut connection.

The final snap is always a carve, but the foil starts getting a bit unstable first. There is no way I would be comfortable putting any more torque on the bolts than I have been. Lets just say that it works for you. I acknowledged that at the beginning that this is probably just that I'm pushing the envelope. , but this thread wouldn't exist if people weren't having problems, and Ive just presented my attempt to improve it. Certainly try all the other suggestions first.

That is correct. The LP RS has a conventional assembly with a bolted-on mast to fuse connection and bolted-on wings.

When I got a 1300 RS wing for my FRS, he included an adapter that fits onto the FRS fuse. It is nice, and it allows for easy exchange of front wings, but you still have to use the threaded rod to remove the adapter. Step in the right direction.

I just leave my FRS assembled all the time. Since I foil in fresh water, this works. By the way, at 192 lb weight, the 940 cm2 wing is plenty for easy lifting and playful foiling. I find I don't ever need the 1300 cm2.

Select to expand quote

Gwarn said..

I think the adaptor is required as the carbon mast would crumble on the edges due to the small footprint at the connection.

The side loads are huge when using wide boards & big wings.
130 kg of downforce through 450-500mm of leverage from the board width & similar from a big wing.

The mast is only about 19mm thick so all that sideways leverage is applied across half the mast thickness.
This is 130kg @ 450-500mm leverage applied to 9mm so ~50:1 ratio. A propeller head could work out the actual loading
I am surprised the masts are not bending but I think the mast sides where it's bolted to the Fuse is getting crushed when loaded up & lets the bolts come loose.
A flanged connection should help this as it would reduce that ratio & also give some side support to the mast.
If there is no movement the bolts cannot come loose.

I think we are simply pushing the original design & materials beyond their limits.
Staboard's connection is well designed & is not done for no reason.

Select to expand quote

AUS 808 said..

Gwarn said..

I think the adaptor is required as the carbon mast would crumble on the edges due to the small footprint at the connection.

The side loads are huge when using wide boards & big wings.
130 kg of downforce through 450-500mm of leverage from the board width & similar from a big wing.

The mast is only about 19mm thick so all that sideways leverage is applied across half the mast thickness.
This is 130kg @ 450-500mm leverage applied to 9mm so ~50:1 ratio. A propeller head could work out the actual loading
I am surprised the masts are not bending but I think the mast sides where it's bolted to the Fuse is getting crushed when loaded up & lets the bolts come loose.
A flanged connection should help this as it would reduce that ratio & also give some side support to the mast.
If there is no movement the bolts cannot come loose.

I think we are simply pushing the original design & materials beyond their limits.
Staboard's connection is well designed & is not done for no reason.

The leverage of the sailor's downward foot pressure times the board width is transferred thru the fin box. While smooth sailing the counter leverage about the fin box is provided by the lateral hydrodynamic lift of the strut. The width of the board doesn't affect the loading at that orange flange at the fuse end. Nor does the width of the wing affect the loading down there during smooth sailing.

It's only when things go wrong, breaching one wing first, running aground, snagging seaweed on one side that the orange flange will do any work.

I suppose also when turning when one side is going faster at a different roll-induced angle of attack there will be a bit of torque applied around the fuse axis. But does the size of the wing affect this? Do you just turn slower with a large wing leaving imbalanced forces about the same?

Hi Ian,
Respect to the theory, but that's not my experience. I don' t breach most sessions. Really never hit the bottom at speed, touch wood. The problem is non existent for me with the original blue wing, infrequent with the 84 and I don't believe Id last more than an hour with the 99, and 9.5 sail on formula board no matter how reserved I foiled. And its not just a matter of tightening the bolts. Judging by the thread the bolts are fatigued or stretching a little. Like I said I've tried all the suggestions and it just shouldn't be so critical.

Given the theory the snap should only ever come with a breach , bottom impact or seaweed. Unless there is some really weird seaweed I'm unaware of, this is absolutely not my experience.

Respect to all the other solutions and theories. Just not helpful to me. As soon as I test the above I will let others know if this has any potential at all, and i will smooth it all up.

Also I love slingshot gear, and I don't think this is an issue for sup, etc. I suspect there would be a market for an improved mast to fuse joiner. But if it doesn't come this could be an option for those who push the boundaries and don't want to be worried about a hypercritical mast to fuse join.

Hoping for some foiling weather soon.

It's always worth challenging a theory. If both wings are lifting equally there will be no sideways strain on the joint. Maybe just running through the turbulence under waves causes a significant short duration imbalance. Rolling going into turns will load it up with differing angles of attack.As you've noted the fulcrum in the port and starboard direction is very close to the bolts, a big amplification. Maybe you should up the Loctite strength to red?

Same goes for Wingfoilers, because the wing is symmetric, they don't need massive twist=grip wrist strength to hold the wing in correct orientation.

My contention is that the side loads are actually less than in the old days with formula boards and 70cm fins. We use to point our toes to rail the board to leeward when going upwind. This bent the fin back to windward under our butt. This was the secret way to get a lot of speed since the bent fin actually exerted some vertical lift to reduce the board's wetted area.. So, the side loads were massive. DT finboxes carried all of these side loads.

Now, with foils, I contend that the side forces are less because we always rail (or roll) the board to windward. This gets the front wing into the act of lifting not only straight up, but also upwind by the sine of the roll angle. Watch the racers. I never see a racer cranking upwind with a level, or even a leeward railed, board. Their board is always railed 10-30 degrees to windward.

Select to expand quote

Heavy1 said..
Hi Ian,
Respect to the theory, but that's not my experience. I don' t breach most sessions. Really never hit the bottom at speed, touch wood. The problem is non existent for me with the original blue wing, infrequent with the 84 and I don't believe Id last more than an hour with the 99, and 9.5 sail on formula board no matter how reserved I foiled. And its not just a matter of tightening the bolts. Judging by the thread the bolts are fatigued or stretching a little. Like I said I've tried all the suggestions and it just shouldn't be so critical.

Given the theory the snap should only ever come with a breach , bottom impact or seaweed. Unless there is some really weird seaweed I'm unaware of, this is absolutely not my experience.

Respect to all the other solutions and theories. Just not helpful to me. As soon as I test the above I will let others know if this has any potential at all, and i will smooth it all up.

Also I love slingshot gear, and I don't think this is an issue for sup, etc. I suspect there would be a market for an improved mast to fuse joiner. But if it doesn't come this could be an option for those who push the boundaries and don't want to be worried about a hypercritical mast to fuse join.

Hoping for some foiling weather soon.

my friend has been doing that for the last 6 months or so and says it works great. He cut down an old tuttle adaptor... looks like you used the pedestal adaptor?

the prototype slingshot fuselage he was testing had something similar that bolted in to the fuse w/ a single screw (there was a picture circulating on here earlier this year of this orange proto fuse).

Putting pressure vertically on the rail causes more bending stress than putting it across the board.
Foil masts are stiffer than any formula fin and they are still visibly flexed in most pictures during the upwind legs.

As for the person breaking bolts: go strapless or move the straps inward and adjust your technique to load the rail less.
Or change foil companies, which is probably the best option and why I sold my Slingshot gear.

Select to expand quote

segler said..
My contention is that the side loads are actually less than in the old days with formula boards and 70cm fins. We use to point our toes to rail the board to leeward when going upwind. This bent the fin back to windward under our butt. This was the secret way to get a lot of speed since the bent fin actually exerted some vertical lift to reduce the board's wetted area.. So, the side loads were massive. DT finboxes carried all of these side loads.

Now, with foils, I contend that the side forces are less because we always rail (or roll) the board to windward. This gets the front wing into the act of lifting not only straight up, but also upwind by the sine of the roll angle. Watch the racers. I never see a racer cranking upwind with a level, or even a leeward railed, board. Their board is always railed 10-30 degrees to windward.

Yes the tuttle box always had to take a lot of side loading on a Formula board. When the windward rail of a formula board lifts clear of water the leverage on it is the same as in a foiling application. But I think that foiing is a little bit harder on the box. The wet hull takes a lot of the reaction when pumping a formula board, but with a foil the pumping continues for a bit after the board has risen.

The good thing about the tuttle box is that it naturally connects to the top and bottom surfaces of the board as a brace for side loads. There will need to be a good block of high density foam connecting the new track system to the top deck otherwise it will peel off. ( Or they will just have to make boards narrower.)

Select to expand quote

segler said..
Now, with foils, I contend that the side forces are less because we always rail (or roll) the board to windward. This gets the front wing into the act of lifting not only straight up, but also upwind by the sine of the roll angle. Watch the racers. I never see a racer cranking upwind with a level, or even a leeward railed, board. Their board is always railed 10-30 degrees to windward.

Yes the side forces are less but they are on a longer lever arm. Take moments about a longitudinal axis through the finbox and mast base. The downward foot pressure the rider can exert on the 450 mm lever arm is what dictates the leverage the strut is limited to generating. As well as moments being balanced, the left and right forces also have to balance. The foil/strut combination has to balance the sail pressure. So if you want to stay sheeted in and ride high on the foil there's no choice other than to cant the board to windward.

Those of us who are still mastering staying level tend to sheet out when the foil rides a bit high. That reduces sail pressure, and hence lateral pressure on the strut which compensates for the now longer lever arm. But that won't win races we should try to lean into the gusts, staying sheeted in, and let the wing do a bit of the lateral work.

Select to expand quote

Ian K said..

segler said..
Now, with foils, I contend that the side forces are less because we always rail (or roll) the board to windward. This gets the front wing into the act of lifting not only straight up, but also upwind by the sine of the roll angle. Watch the racers. I never see a racer cranking upwind with a level, or even a leeward railed, board. Their board is always railed 10-30 degrees to windward.

Yes the side forces are less but they are on a longer lever arm. Take moments about a longitudinal axis through the finbox and mast base. The downward foot pressure the rider can exert on the 450 mm lever arm is what dictates the leverage the strut is limited to generating. As well as moments being balanced, the left and right forces also have to balance. The foil/strut combination has to balance the sail pressure. So if you want to stay sheeted in and ride high on the foil there's no choice other than to cant the board to windward.

Those of us who are still mastering staying level tend to sheet out when the foil rides a bit high. That reduces sail pressure, and hence lateral pressure on the strut which compensates for the now longer lever arm. But that won't win races we should try to lean into the gusts, staying sheeted in, and let the wing do a bit of the lateral work.

I am still visualising uneven forces between the board & foil.
If the board & rig weigh say 20kg & the rider is 130kg the foil must lift 150kg to fly, 75kg per side of wing.
The 130kg is windward by 450mm and leverage through the TB should be bending the mast & loading the bolted connection.
Everything would be canted to windward but the wing still has to maintain upward thrust to maintain flight.
Each side of the wing can only produce the same amount of lift so the forces must be unbalanced.

You could put numbers on your hypothetical situation. A lot of that 130 Kg is supported through the harness lines, the rig is canted right over. There might only be half of it as downward pressure on the rail. Someone analysed the forces of a hiked out windsurfer here before but half will do. The weight of the rig is on the centreline so it has no contribution to moments about a longitudinal axis thru the fin box . So the counterclockwise moment looking from behind on a board on port tack is 75 X 0.45 X 9.8 Nm. There's got to be an equal clockwise moment or the board will start rolling one way or the other. If the strut(mast) has 40 cm in the water and is 110 long its hydrodynamic lift is centred 90cm below. Twice as long a lever arm so the strut can only generate 75/2 kg of lateral force = 37.5kg. If the strut stays straight, the wing, being symmetric, doesn't contribute any moments in this calculation.

Now if you do the geometry of the hiked out sailor, ( it's somewhere around, done in great detail, on this forum) the height if the sail etc you might find the properly sheeted in sail can generate 47.5 kg laterally. (pulling numbers out of the air here but it could be that much for a 130 kg sailor). But if you cranked up the strut angle of attack to generate 47.5 kg to match the sail you'd just roll to leeward. Can't be done. Solution is to sheet out or to cant to windward so that extra 10kg is supplied by the foil. The foil now has to do 10 kg horizontal as well as 150kg vertical. So it has to be angle-of-attacked to provide sqrt( 150*150 + 10*10) of lift. The cant angle angle is artan 10/150 = 4 degrees tilt. Not much, I pulled the wrong numbers out of the air, but that's the idea.

Of course the original counterclockwise moment is a little less now as the horizontal distance is reduced to say 440mm rather than 450mm - foiling is a continual balancing act it's amazing we can do out at all. And we've assumed the strut doesn't bend. If it does the wing will contribute counterclockwise moment around the fin box needing another minor refinement in the calculations.

Here's a bit of asymmetric loading of a T foil. The most leeward wing is skating the surface. The inboard wing doing most of the heavy lifting by the look of it. 6.5 tonnes!

Wow, when my foil rides too high, I sheet in, not out. This increases mast base pressure DOWN to get the foil back down.

A windsurfing sail deflects air a bit upwards as well as sideways so it makes sense that sheeting in will increase mast base pressure by deflecting more air upwards.

But as soon as you do that there's a combination of other things that have to be readjusted. It's amazing what sort of balancing act we do automatically.

I was wondering how racers keep full power on without upsetting the roll equilibrium.

What did you do when your Formula board lifted a windward rail with its 70 cm fin?

Select to expand quote

Ian K said..
You could put numbers on your hypothetical situation. A lot of that 130 Kg is supported through the harness lines, the rig is canted right over. There might only be half of it as downward pressure on the rail. Someone analysed the forces of a hiked out windsurfer here before but half will do. The weight of the rig is on the centreline so it has no contribution to moments about a longitudinal axis thru the fin box . So the counterclockwise moment looking from behind on a board on port tack is 75 X 0.45 X 9.8 Nm. There's got to be an equal clockwise moment or the board will start rolling one way or the other. If the strut(mast) has 40 cm in the water and is 110 long its hydrodynamic lift is centred 90cm below. Twice as long a lever arm so the strut can only generate 75/2 kg of lateral force = 37.5kg. If the strut stays straight, the wing, being symmetric, doesn't contribute any moments in this calculation.

Now if you do the geometry of the hiked out sailor, ( it's somewhere around, done in great detail, on this forum) the height if the sail etc you might find the properly sheeted in sail can generate 47.5 kg laterally. (pulling numbers out of the air here but it could be that much for a 130 kg sailor). But if you cranked up the strut angle of attack to generate 47.5 kg to match the sail you'd just roll to leeward. Can't be done. Solution is to sheet out or to cant to windward so that extra 10kg is supplied by the foil. The foil now has to do 10 kg horizontal as well as 150kg vertical. So it has to be angle-of-attacked to provide sqrt( 150*150 + 10*10) of lift. The cant angle angle is artan 10/150 = 4 degrees tilt. Not much, I pulled the wrong numbers out of the air, but that's the idea.

Of course the original counterclockwise moment is a little less now as the horizontal distance is reduced to say 440mm rather than 450mm - foiling is a continual balancing act it's amazing we can do out at all. And we've assumed the strut doesn't bend. If it does the wing will contribute counterclockwise moment around the fin box needing another minor refinement in the calculations.

So you agree

Select to expand quote

AUS 808 said..

So you agree

Sorry got carried away thinking out loud. It's just that statics and dynamics was my favourite subject in yr12. 1970, and it still haunts me!

Your last statement " so the forces must be unbalanced " fired me up. To go in a straight line at constant speed the forces up/down, left /right and fore and aft must all balance. And the moments about any axis you care to choose must balance also otherwise you'll begin winding up in one direction or another.

It's a solid theory of classical mechanics. Nothing flaky about it. it's not like climatology. Maybe Quantum mechanics and light speed stuff bends the rules?

But maybe that wasn't what you meant? Maybe I've misapplied one of those classical rules, forgotten something? We can always think again.

Ian asked, "What did you do when your Formula board lifted a windward rail with its 70 cm fin?"

Answer: I sheeted in. Well, more. When I was out on the rail in the footstraps with my 195 lb weight, a 70cm fin rarely railed up. I always had to do that manually by pointing my toes aggressively. In any case, if anything ever got out of whack, sheeting in solved the problem.

There is a reason why instructors will always tell you, "sheet in."

If it works just do it. But from an engineering point of view why? Does sheeting in deflect more air upwards, pushing down on the mast base? Does sheeting in stand you up, taking weight off the mast base and onto the rail where it has more leverage over the fin? Does sheeting in move the sail forwards, for a little swerve off the wind that reduces fin lift. Stand the sail more upright? Or a combination of all these and some more we haven't thought of?


We could get USA46 onto it. www.seabreeze.com.au/forums/Windsurfing/General/Correct-way-to-calculate-forces-moments-in-windsurfing


That's the trouble with slappers. The centre of hull lift wanders all over the place. Easy to sail but hard to analyse. At least with foils the lifting bits stay put. Easier to analyse but harder to sail. Wasn't a good question.


How did we get here from the subject of bolt failure? Did the engineers do all this in much greater detail when sizing the bolts and mating surfaces of the slingshot foil? I reckon they did before the AC75s were launched. Will we have a foil break off one of those before the cup is decided?

Interesting problem. I never knew this was an issue. Sadly, due to weather changes for the winter I just put mine in storage for the season. Does SS provide any specs for torquing thd bolts? I'm wondering if high tensile strength steel bolts would help. Due to corrosion risks you'd need to remove them and thoroughly clean after every use. At some point, the threads inside the aluminum mast will reach their limit and strip.
If this problem is mostly from the C position, that would suggest the mast foot should have been made longer (front to rear ... longer chord I believe is the correct term). My gut feeling is it's actually the combination of forces due to longitudinal and lateral loads. A flat flange across the top of the fuse could be a game changer.


I like the flange Heavy1 made up but the front edge looks a bit blunt. I'm anxious to hear how that works out. I'm at 105~110 kg with the i99 so I expect this situation might be a problem for me too at some point.

Select to expand quote

sunsetsailboards said..

Heavy1 said..
Hi Ian,
Respect to the theory, but that's not my experience. I don' t breach most sessions. Really never hit the bottom at speed, touch wood. The problem is non existent for me with the original blue wing, infrequent with the 84 and I don't believe Id last more than an hour with the 99, and 9.5 sail on formula board no matter how reserved I foiled. And its not just a matter of tightening the bolts. Judging by the thread the bolts are fatigued or stretching a little. Like I said I've tried all the suggestions and it just shouldn't be so critical.

Given the theory the snap should only ever come with a breach , bottom impact or seaweed. Unless there is some really weird seaweed I'm unaware of, this is absolutely not my experience.

Respect to all the other solutions and theories. Just not helpful to me. As soon as I test the above I will let others know if this has any potential at all, and i will smooth it all up.

Also I love slingshot gear, and I don't think this is an issue for sup, etc. I suspect there would be a market for an improved mast to fuse joiner. But if it doesn't come this could be an option for those who push the boundaries and don't want to be worried about a hypercritical mast to fuse join.

Hoping for some foiling weather soon.

my friend has been doing that for the last 6 months or so and says it works great. He cut down an old tuttle adaptor... looks like you used the pedestal adaptor?

the prototype slingshot fuselage he was testing had something similar that bolted in to the fuse w/ a single screw (there was a picture circulating on here earlier this year of this orange proto fuse).

Thanks Sunsetsailboards. Ive tried it now and its fantastic. Foiled big wing (99) 3 hrs, no hint of trouble, but amazingly the whole set up is so much more stable to use. I'm stoked!!!. Your friend beat me to the idea. Definite highly recommended for heavy windfoilers on big wings.

Select to expand quote

Heavy1 said..
Hi Ian,
Respect to the theory, but that's not my experience. I don' t breach most sessions. Really never hit the bottom at speed, touch wood. The problem is non existent for me with the original blue wing, infrequent with the 84 and I don't believe Id last more than an hour with the 99, and 9.5 sail on formula board no matter how reserved I foiled. And its not just a matter of tightening the bolts. Judging by the thread the bolts are fatigued or stretching a little. Like I said I've tried all the suggestions and it just shouldn't be so critical.

Given the theory the snap should only ever come with a breach , bottom impact or seaweed. Unless there is some really weird seaweed I'm unaware of, this is absolutely not my experience.

Respect to all the other solutions and theories. Just not helpful to me. As soon as I test the above I will let others know if this has any potential at all, and i will smooth it all up.

Also I love slingshot gear, and I don't think this is an issue for sup, etc. I suspect there would be a market for an improved mast to fuse joiner. But if it doesn't come this could be an option for those who push the boundaries and don't want to be worried about a hypercritical mast to fuse join.

Hoping for some foiling weather soon.

Fact. The cut down pedestal allowed me to windfoil 3 hrs on 99 infinity, no issue at all which is unprecedented for me.
Fact . Im shocked by how much more stable the foil feels to me. Massive increase in confidence. massive decrease in crashes.
Fact. despite the completely unfinished shaping the extra drag was unnoticeable to me.

Speculation: Its so much more stable I speculate that the wing resists instantaneous roll inputs and with my weight flexes mico amounts at the mast fuse interface. Given the weird angles the foil is traveling through the water, (slight up, slight yaw), any flex, steers the foil in weird ways, possibly even stressing the fuse mast interface even more. Generally the wings may be balanced but surely they resist rapid wobble movements. Water at speed is pretty resistant to sudden roll movements. I think this is why the set up feels so much more stable now. This could loosen bolts, but even if the blots are red lock tighted any micro flex in metal is going to eventually fatigue, and snap.

So how do you get super red lock tight broken bolts out of the mast. Speculation : this is a bad idea.

Opinion: I love and highly recommend slingshot gear for wind foiling. I highly recommend the 84 and 99 infinity wings for heavy weights. However my suggestion is that for confidence in not snapping bolts, and even more so for a much more stable enjoyable ride, the cut down pedestal is a dramatic improvement, and I hope slingshot bring out a purpose built adapter.

Select to expand quote

Heavy1 said..

Heavy1 said..
Hi Ian,
Respect to the theory, but that's not my experience. I don' t breach most sessions. Really never hit the bottom at speed, touch wood. The problem is non existent for me with the original blue wing, infrequent with the 84 and I don't believe Id last more than an hour with the 99, and 9.5 sail on formula board no matter how reserved I foiled. And its not just a matter of tightening the bolts. Judging by the thread the bolts are fatigued or stretching a little. Like I said I've tried all the suggestions and it just shouldn't be so critical.

Given the theory the snap should only ever come with a breach , bottom impact or seaweed. Unless there is some really weird seaweed I'm unaware of, this is absolutely not my experience.

Respect to all the other solutions and theories. Just not helpful to me. As soon as I test the above I will let others know if this has any potential at all, and i will smooth it all up.

Also I love slingshot gear, and I don't think this is an issue for sup, etc. I suspect there would be a market for an improved mast to fuse joiner. But if it doesn't come this could be an option for those who push the boundaries and don't want to be worried about a hypercritical mast to fuse join.

Hoping for some foiling weather soon.

Fact. The cut down pedestal allowed me to windfoil 3 hrs on 99 infinity, no issue at all which is unprecedented for me.
Fact . Im shocked by how much more stable the foil feels to me. Massive increase in confidence. massive decrease in crashes.
Fact. despite the completely unfinished shaping the extra drag was unnoticeable to me.

Speculation: Its so much more stable I speculate that the wing resists instantaneous roll inputs and with my weight flexes mico amounts at the mast fuse interface. Given the weird angles the foil is traveling through the water, (slight up, slight yaw), any flex, steers the foil in weird ways, possibly even stressing the fuse mast interface even more. Generally the wings may be balanced but surely they resist rapid wobble movements. Water at speed is pretty resistant to sudden roll movements. I think this is why the set up feels so much more stable now. This could loosen bolts, but even if the blots are red lock tighted any micro flex in metal is going to eventually fatigue, and snap.

So how do you get super red lock tight broken bolts out of the mast. Speculation : this is a bad idea.

Opinion: I love and highly recommend slingshot gear for wind foiling. I highly recommend the 84 and 99 infinity wings for heavy weights. However my suggestion is that for confidence in not snapping bolts, and even more so for a much more stable enjoyable ride, the cut down pedestal is a dramatic improvement, and I hope slingshot bring out a purpose built adapter.

Sounds like this is the answer, a better connection stops any movement & therefore the bolts stay tight.
The masts are not very strong, they only have a narrow profile & thin wall thickness so the connection is not great when you add a wide foil with a lot of leverage.
I suspect a bit of sideways movement was the problem.
The adaptor is now supporting the mast better with side contact as well as end contact & across the full width of the fuse. I believe this halves the leverage & reduces any movement.
Don't use Loctite or tape, it's a bandaid only & getting it apart will be messy, red Loctite will require heat to release.

On another note, while foiling on Sunday I could feel a buffeting affect from the foil, not sure if it was sideways against the mast or the wing doing something weird, I only feel it when in very light conditions & not powered up.

Sorry, but I would run away from a foil that did as fast as I could! And by fixing the problem you risk having a catastrophic mast/fuselage failure, instead of bolts loosening and breaking.

Select to expand quote

Sandman1221 said..
Sorry, but I would run away from a foil that did as fast as I could! And by fixing the problem you risk having a catastrophic mast/fuselage failure, instead of bolts loosening and breaking.

Good point. The aluminum mast could break, but why would it be more likely to break now. Besides a "catastrophic mast failure" would really only be similar to the bolts breaking in terms of getting home and the size of the crash. And you can buy a new mast. I will certainly report back if I have a mast break.