I had both m8 50 mm bolts snap at the mast and fuselage connection today when I overfoiled. Not a big breach. Landed and kept going but immediately knew something was wrong. Fortunately the mast caught the wing and pinned it against the bottom of the board. Immediately jumped in to save the wing fuselage and stabiliser. Was interesting trying to uphaul and sail home hanging onto the fuselage and wings.
The bolts snapped flush with the mast. Will be fun trying to drill into titanium.
I look after my gear wash it down disassemble and lanolin marine grease after use. I bought from new. Has this happened to anyone else?

You may find they come out easier than you think. Now there is no tension on the threads and you have kept them clean and well greased. Buy a left handed drill bit, obviously put your drill in reverse and soon as the drill bites it will probably wind the bolt out. Hope this works.

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Swindy said..
You may find they come out easier than you think. Now there is no tension on the threads and you have kept them clean and well greased. Buy a left handed drill bit, obviously put your drill in reverse and soon as the drill bites it will probably wind the bolt out. Hope this works.

First , drill a 2 mm hole about 2 mm deep

Thanks Swindy
your were right.
I unfortunately had not read your suggestion and used a right hand thread. It pushed it way in. Will have to find a left hand thread drill that cuts titanium. The thread extractor I tried later only scratched it.

As long as it hasn't bottomed out hard it should still be quite easy.

YES, this is the weak link in this set up. I had the same thing go wrong and just like you I got lucky and was able to grab the wing.I now just use stainless bolt and now check all the bolts for tightness before each ride. It also deformed the mast so I flipped it 180 and filed it down to fit in the tuttle head and have not had it happen again. I foil in 18-30 mph winds with the 76 on the 105. I feel that this set is a good entry level set up but it's bound to fail once the rider becomes efficient and more aggressive especially the heavier ones like myself who ride in windy and swelly conditions.
As far as getting the bolts out it was easy they just spun right out with a punch to spin them. The pictures show how the mast got deformed so I felt uneasy about the gap and the flipped the mast over and made it work. 30+ days on it now I have been looking at upgrading to the moses foil 111 mast with the 873,790 and 683 wings butt they are far and few between here in the US or I could buy the SS ghost whisper 111 and add the wing butt that route is much more expensive. On a side note I was told that SS will be releasing the phantasm set up in August, butt I have not seen any pictures only the shots of tonys set up . I'm not going to hold my breath on that as I feel that most everything with slingshot is way hyped up in a used car salesman type of way.

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MrA said..
I had both m8 50 mm bolts snap at the mast and fuselage connection today when I overfoiled. Not a big breach. Landed and kept going but immediately knew something was wrong. Fortunately the mast caught the wing and pinned it against the bottom of the board. Immediately jumped in to save the wing fuselage and stabiliser. Was interesting trying to uphaul and sail home hanging onto the fuselage and wings.
The bolts snapped flush with the mast. Will be fun trying to drill into titanium.
I look after my gear wash it down disassemble and lanolin marine grease after use. I bought from new. Has this happened to anyone else?

I thought the wings float...I guess not when still attached to fuselage I wonder if they should be using 3 bolts instead of 2 to connect the fuse and mast like my old NP alu, the mast would usually bend before the bolts break.

Should we be leashing to the fuse instead of under the tuttle head? My new SS has less than 2 runs on it and that scares the hell out me, lucky you were able to grab it!.

I felt the same way the first couple of sessions. Now that i'm using stainless bolts off the self I just replace them every couple of weeks (10 sessions + or - ) just to keep it off my mind. Also before this happened I hadn't been checking the bolts for tightness before going out ( I don't disassemble it as a have a van) So I feel this is not a problem for me anymore. I'm just focused on preventive maintenance now.



Sorry about the sideway picture

Yes I am sure these titanium bolts are not sourced from top of the line aerospace manufacturers. When I first got my foil I was making those bolts way to tight and managed to round out the allen heads a bit so I went to the aluminum ones and never had a problem. Iam sure the bigger wings put way more stress on the mast,but overall the slingshot makes learing to foil easy and fun and Ive have lots learn.

Oops I meant stainless not a aluminum.

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CAN17 said..

MrA said..
I had both m8 50 mm bolts snap at the mast and fuselage connection today when I overfoiled. Not a big breach. Landed and kept going but immediately knew something was wrong. Fortunately the mast caught the wing and pinned it against the bottom of the board. Immediately jumped in to save the wing fuselage and stabiliser. Was interesting trying to uphaul and sail home hanging onto the fuselage and wings.
The bolts snapped flush with the mast. Will be fun trying to drill into titanium.
I look after my gear wash it down disassemble and lanolin marine grease after use. I bought from new. Has this happened to anyone else?

I thought the wings float...I guess not when still attached to fuselage I wonder if they should be using 3 bolts instead of 2 to connect the fuse and mast like my old NP alu, the mast would usually bend before the bolts break.

Should we be leashing to the fuse instead of under the tuttle head? My new SS has less than 2 runs on it and that scares the hell out me, lucky you were able to grab it!.

Maybe they do float. I have not checked. I wasn't risking losing it at the time. Perhaps that is why I didn't lose it. It was certainly getting heavy holding it with one hand and holding the boom with the other when sailing home.
I was using the 84 cm wing at the time. So maybe there is more stress on it. I would have thought it could take a small breach though. How do they loop and land (albeit with smaller wings) in the videos? They are not just using the carbon foils in the earlier slingshot vids.

Gwarn
Is stainless stronger than titanium or is it just cheaper and you change them regularly?
this has me spooked for future use.

The phantasm set up is bound to be expensive but hopefully they fix this issue. Will be interesting to see how the have the different mast positions A, B and C
I have not seen anywhere in the slingshot material saying how often to change the bolts. By the way the bolts are $12 each on the Aussie slingshot site but are $9 on the Aussie ride engine website.
it could add up getting 2 at a time plus delivery if they have to be done every couple of months.

I bought my foil new in October 2018.
I have been happy with it as a learning platform and have had good service from slingshot when I had an unusual issue with a mast early on.

7Nation if you read this can you give us some feedback on the issue?

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KDog said..
Oops I meant stainless not a aluminum.

Low to medium grades of Stainless steel are weaker than titanium and Ti is lighter and more corrosion resistant for salt water users.
What grade stainless steel did you use. If it's not a really high grade then why would your stainless bolts not break too?

They are not titanium bolts. My Slingshot came with generic stainless bolts, with no head stamping to indicate they were made to any industry standards for strength.

I replaced mine with proper stainless A4 bolts with correct stampings. Not some Chinese garbage bolts.

The foil brands who claim titanium bolts, are really just stainless bolts with titanium coating.

I used my new slingshot foil for the first time on the weekend.
i must admit I was sceptical of the mast fuse connection when I first put it together.
i think there will be lots of broken bolts with the use of large foils and long masts especially and heavier riders.
It's a good set up for Metal fatigue in the bolts
in my opinion.

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snides8 said..
I used my new slingshot foil for the first time on the weekend.
i must admit I was sceptical of the mast fuse connection when I first put it together.
i think there will be lots of broken bolts with the use of large foils and long masts especially and heavier riders.
It's a good set up for Metal fatigue in the bolts
in my opinion.

I snapped my titanium bolts (fuse/mast) a year ago, I suspect that I hadn't tightened them sufficiently, perhaps they worked a little loose making them easier to snap.
I reported it to Slingshot USA, they responded saying they would pass the info on to Wyatt (Slingshot Brand Mgr). All good

I replaced the bolts with stamped stainless steel A4 70 - cost only a few bucks each.
I've foiled 150+ sessions, 4500 km on these bolts often in big swells and winds, with all wing sizes including 84cm.
Might be time to renew them (preventive maintenance) - does stainless weaken appreciably with that amount of use?

I reckon you could over-engineer anything so it never breaks - but then you're probably dragging extra size/weight around and perhaps incurring an additional cost.
I'm happy to replace a couple of bolts every year if need be, and enjoy the carve of the awesome Slingshot foils

Stainless bolts have a bigger yield range than titanium. This means that stainless bolts will stretch more before breaking. Titanium will break without much yield (more brittle). I used to work in a metallurgy lab that tested all these alloys.

The overall tensile strength for most stainless and titanium at sizes from M6 through 1/4-20 to M8 to M10 is plenty for foiling. If any of them breaks, it is because of a flaw in the grain structure or manufacturing.

I use nothing but stainless, as do 99% of my foiling buds in the gorge. We have not had any problems. Most of us tap our gear from M6 to 1/4-20 in order to have a good selection of stainless bolts and screws in the USA.

I use heated high strength bolts(ISO 10642). But they are afraid of corrosion(I ride in fresh water). But very durable and does not bend particularly M6 for fixing deep tuttle.

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segler said..
Stainless bolts have a bigger yield range than titanium. This means that stainless bolts will stretch more before breaking. Titanium will break without much yield (more brittle). I used to work in a metallurgy lab that tested all these alloys.

The overall tensile strength for most stainless and titanium at sizes from M6 through 1/4-20 to M8 to M10 is plenty for foiling. If any of them breaks, it is because of a flaw in the grain structure or manufacturing.

I use nothing but stainless, as do 99% of my foiling buds in the gorge. We have not had any problems. Most of us tap our gear from M6 to 1/4-20 in order to have a good selection of stainless bolts and screws in the USA

Makes sense. Thank you for clarifying why stainless is a better choice then titanium. Or as mentioned "Chinese titanium coated bolts"

What type of bolts did those who changed to stainless buy. I realize some mentioned M8 x 50mm a4 stainless. I assume it's metric does anyone know the thread pitch( I guess I could ask slingshot)

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azymuth said..
I replaced the bolts with stamped stainless steel A4 70

Should the bolts be stamped a4 70. Did you stick with the Allen head?

8 mmx1.25 thread pitch is a very common size ,A4 stainless is a little harder to find at your local hardware store.I wouldn't be against using non stainless like Atonmik said because I have to remove my mast every time for transport.

My local hardware stores are hopeless for metric stainless, even the marine shops are terrible. I am considering running a leash down to my fuselage now.

I get mine via Ebay. Perhaps a risky approach?

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CAN17 said..

segler said..
Stainless bolts have a bigger yield range than titanium. This means that stainless bolts will stretch more before breaking. Titanium will break without much yield (more brittle). I used to work in a metallurgy lab that tested all these alloys.

The overall tensile strength for most stainless and titanium at sizes from M6 through 1/4-20 to M8 to M10 is plenty for foiling. If any of them breaks, it is because of a flaw in the grain structure or manufacturing.

I use nothing but stainless, as do 99% of my foiling buds in the gorge. We have not had any problems. Most of us tap our gear from M6 to 1/4-20 in order to have a good selection of stainless bolts and screws in the USA

Makes sense. Thank you for clarifying why stainless is a better choice then titanium. Or as mentioned "Chinese titanium coated bolts"

What type of bolts did those who changed to stainless buy. I realize some mentioned M8 x 50mm a4 stainless. I assume it's metric does anyone know the thread pitch( I guess I could ask slingshot)

azymuth said..
I replaced the bolts with stamped stainless steel A4 70

Should the bolts be stamped a4 70. Did you stick with the Allen head?

In the US I would check McMaster-Carr.com. They have EVERYTHING.

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gorgesailor said..

CAN17 said..

segler said..
Stainless bolts have a bigger yield range than titanium. This means that stainless bolts will stretch more before breaking. Titanium will break without much yield (more brittle). I used to work in a metallurgy lab that tested all these alloys.

The overall tensile strength for most stainless and titanium at sizes from M6 through 1/4-20 to M8 to M10 is plenty for foiling. If any of them breaks, it is because of a flaw in the grain structure or manufacturing.

I use nothing but stainless, as do 99% of my foiling buds in the gorge. We have not had any problems. Most of us tap our gear from M6 to 1/4-20 in order to have a good selection of stainless bolts and screws in the USA

Makes sense. Thank you for clarifying why stainless is a better choice then titanium. Or as mentioned "Chinese titanium coated bolts"

What type of bolts did those who changed to stainless buy. I realize some mentioned M8 x 50mm a4 stainless. I assume it's metric does anyone know the thread pitch( I guess I could ask slingshot)

azymuth said..
I replaced the bolts with stamped stainless steel A4 70

Should the bolts be stamped a4 70. Did you stick with the Allen head?

In the US I would check McMaster-Carr.com. They have EVERYTHING.

I'm in the great white north. HD supply Brafasco seem to usually have everything but they only carry 18/8 which I learned is a2 not a4. Is this a big deal if it is a2 or a4.
A4 is more of a "marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304"

Two common grades:
-Grade 304 stainless steel (A2): chromium 18% + nickel 8% (known as '18/8')

-Grade 316 stainless steel (A4): chromium 18% + nickel 8% + molybdenum 3% (known as '18/8/3')

From my research it seems the only difference in A4 is it contains "Molybdenum is a silvery-white metal that is ductile and highly resistant to corrosion. It has one of the highest melting points of all pure elements - only the elements tantalum and tungsten have higher melting points. Molybdenum is also a micronutrient essential for life"

My main question is are A2 bolts going to rust. I think A4 is a better choose because of that. Will they not last as long as A4 bolts, strength wise??

Didn't we learn in highschool that pure steel os the strongest?
Add anything else might make it more brittle.

Strong is the balance between stiff and flexible.

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CAN17 said..

gorgesailor said..

CAN17 said..

segler said..
Stainless bolts have a bigger yield range than titanium. This means that stainless bolts will stretch more before breaking. Titanium will break without much yield (more brittle). I used to work in a metallurgy lab that tested all these alloys.

The overall tensile strength for most stainless and titanium at sizes from M6 through 1/4-20 to M8 to M10 is plenty for foiling. If any of them breaks, it is because of a flaw in the grain structure or manufacturing.

I use nothing but stainless, as do 99% of my foiling buds in the gorge. We have not had any problems. Most of us tap our gear from M6 to 1/4-20 in order to have a good selection of stainless bolts and screws in the USA

Makes sense. Thank you for clarifying why stainless is a better choice then titanium. Or as mentioned "Chinese titanium coated bolts"

What type of bolts did those who changed to stainless buy. I realize some mentioned M8 x 50mm a4 stainless. I assume it's metric does anyone know the thread pitch( I guess I could ask slingshot)

azymuth said..
I replaced the bolts with stamped stainless steel A4 70

Should the bolts be stamped a4 70. Did you stick with the Allen head?

In the US I would check McMaster-Carr.com. They have EVERYTHING.

I'm in the great white north. HD supply Brafasco seem to usually have everything but they only carry 18/8 which I learned is a2 not a4. Is this a big deal if it is a2 or a4.
A4 is more of a "marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304"

Two common grades:
-Grade 304 stainless steel (A2): chromium 18% + nickel 8% (known as '18/8')

-Grade 316 stainless steel (A4): chromium 18% + nickel 8% + molybdenum 3% (known as '18/8/3')

From my research it seems the only difference in A4 is it contains "Molybdenum is a silvery-white metal that is ductile and highly resistant to corrosion. It has one of the highest melting points of all pure elements - only the elements tantalum and tungsten have higher melting points. Molybdenum is also a micronutrient essential for life"

My main question is are A2 bolts going to rust. I think A4 is a better choose because of that. Will they not last as long as A4 bolts, strength wise??

I believe 316 is more corrosion resistant but marginally weaker than 18-8. However, I leanrn't that 18-8 is not as precise a classification & can include 303,304 or perhaps other variations. IMO 316 is best for parts you can't inspect often for corrosion but in my experience 18-8 usually works fine for parts you are using allot - installing/uninstalling etc... In any case McMaster has good variety of 316 screws & bolts.

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Windbot said.. I am considering running a leash down to my fuselage now.

I will be too until I find bolts. But has anyone tested if the wings float with the fuse attached? At the end of the day it's still bad news if you have to try and get broken bolts out of your mast. And the possibility of wing damage if your board impacts the wings after a bolt failure( assuming wings and fuse don't sink).

The Infinity 84 on the 61cm mast does not float in fresh water (the wing itself would, but not the wing/fuse/mast assembly). I haven't sailed it in saltwater yet but I doubt it would make a significant difference. I use a leash made of kite-line, looped around the top of the mast and attached to the back footstrap. It's a little bit of a weed-magnet but provides some measure of security against a blowout.

In Windance in Hood River I saw a kite foil leash that went to a stick-on base at the top of the foil mast. If your foil does not have a flange (like my AFS-2) you can't just loop some kite line around the mast; it will slip off the top.

So, the stick-on seems OK, but they did not have any for sale as a separate item.

So, you might try those stick-on bases for zip ties. I use those in my fishing boat. They stick very well.

If you use kite line, be sure to get the type that is encapsulated in a plastic sheath. They survive many many tyings and untyings without fraying. If you can see the braid, it will fray.

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gorgesailor said..
I believe 316 is more corrosion resistant but marginally weaker than 18-8.

Bolt Depot says the opposite, that 316 is stronger. ASM data sheets seem to confirm that - they give 580 MPa as the tensile strength for 316, and 505 MPa for 304 (from asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ316A and asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A).

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segler said..
In Windance in Hood River I saw a kite foil leash that went to a stick-on base at the top of the foil mast. If your foil does not have a flange (like my AFS-2) you can't just loop some kite line around the mast; it will slip off the top.

So, the stick-on seems OK, but they did not have any for sale as a separate item.

So, you might try those stick-on bases for zip ties. I use those in my fishing boat. They stick very well.

If you use kite line, be sure to get the type that is encapsulated in a plastic sheath. They survive many many tyings and untyings without fraying. If you can see the braid, it will fray.

www.windance.com/NSI-SUP-Rubber-Mounting-Plates/13560/

I've seen one locally.

Someone is going to make a killing selling 1m long pieces of used kite line.