I was told by a very reputable company owner to use marine lithium grease on my foil screws, but what I am finding is sand sticks to the grease and gums up the threads on the screws and in the nuts. I was making it hard for one wing screw to go in, felt like it was cross threading. I was also told a long time ago by Bruno at AFS to use WD-40 on the foil screws and will be going back to that. Note all my screws are A4 stainless steel.
Tefgel is really good stuff
WD-40 won't do much more than clean it, then evaporate
Select to expand quoteaeroegnr said..
Tefgel is really good stuff
WD-40 won't do much more than clean it, then evaporate
WD-40 is a lubricant and also anti-corrosive after it evaporates, that is more than A4 stainless steel needs IMO.
My concern about Tefgel is based on its name, gel, and since it is a paste would get sand stuck in it too. I do not have a corrosion problem, was just using the lithium grease as a lubricant that did not wash away, but that is the problem!
WD-40 doesn't lubricate much at the best of times abs definitely not in water.
You shouldn't need any lube. I never bother with my foil which is disassembled each use.
Select to expand quoteGrantmac said..
WD-40 doesn't lubricate much at the best of times abs definitely not in water.
You shouldn't need any lube. I never bother with my foil which is disassembled each use.
I agree, did not mean I would spray on WD-40 every time, just once in a while, figure it can not hurt to have a little lubricant and corrosion protection on the screw threads.
The afs foils are from memory carbon/stainless components, far less susceptible to electrolytic reactions/corrosion than aluminium in the same mix. Which is more than likely why WD40 has been ok for it. But WD40 only provides a thin film of protection, which washes off in no time flat in salt water.Its more or less a waste of a can of WD40 putting it on.
whilst grease and sand don't mix well, if you can manage to not drop the threaded parts in the sand, grease is a more permanent film that doesn't wash off easily and gives better protection than WD40. Tefgel is even better, its designed specifically for the job.
The bolts that get undone every time you pack up to go home don't need anything. Put Tefgel on the bolts that don't get undone for a season or more. Isn't that the way it works?
Select to expand quoteIan K said..
The bolts that get undone every time you pack up to go home don't need anything. Put Tefgel on the bolts that don't get undone for a season or more. Isn't that the way it works?
Yes, I still use lithium grease on the stabilizer screws because they do not get undone often.
Select to expand quoteLeeD said..
Attach and detach in a clean spot.
Once tightened, sand stays out.
In 14-20 knots setting up on beach sand gets into everything no matter how careful I am. Do not have a sheltered place to set up gear.
Select to expand quoteSubsonic said..
The afs foils are from memory carbon/stainless components, far less susceptible to electrolytic reactions/corrosion than aluminium in the same mix. Which is more than likely why WD40 has been ok for it. But WD40 only provides a thin film of protection, which washes off in no time flat in salt water.Its more or less a waste of a can of WD40 putting it on.
whilst grease and sand don't mix well, if you can manage to not drop the threaded parts in the sand, grease is a more permanent film that doesn't wash off easily and gives better protection than WD40. Tefgel is even better, its designed specifically for the job.
That is what I want, a thin film of protection/lubrication so I do not wear out the inserts in the fuselage used to mount the wing. Replaced them once after an accident damaged them, do not want to have to replace them again!
TefGel on bolts covered with couple wraps of teflon plumber's tape. No need to over torque to keep thing tight. Plus easy to remove. I leave the wing and stab attached all season. Sort of Belts and Suspenders overkill. Doesn't take much time to pull off old and apply a fresh tape at the end of the session on the fuse mounting bolts. Supposedly the tape reduces the chance of "vibrations" from loosening the bolts. Seems to work.
TefGel alone. As noted above. Just don't expose it to grit. Any grease will collect sand, dirt...
Select to expand quoteOldGuy3 said..
No need to over torque to keep thing tight.
Only yesterday I stumbled across an engineer on the internet talking about torque and loosening of bolts.
The primary purpose of torque is not to prevent them coming loose but to preload the mating surfaces. If an engineer selects M8 bolts then he intended them to be torqued to spec.
www.engineeringtoolbox.com/metric-bolts-maximum-torque-d_2054.html
If the threads are lubricated you knock off ~30%. For M8s it looks like close to 30Nm dry, a bit over 20 if lubricated.
The max torque you can apply with a screwdriver handle is about 10 Nm. Best use a torque wrench to at least calibrate your tightening every now and then. You're not going to get m8 bolts tight enough with just a handle, you'll need some sort of leverage extension.
www.researchgate.net/figure/Maximum-torque-a-person-could-produce-on-a-handle-significantly-varied-for-the-handle_fig3_51698033
Select to expand quoteIan K said..OldGuy3 said..
No need to over torque to keep thing tight.
Only yesterday I stumbled across an engineer on the internet talking about torque and loosening of bolts.
The primary purpose of torque is not to prevent them coming loose but to preload the mating surfaces. If an engineer selects M8 bolts then he intended them to be torqued to spec.
www.engineeringtoolbox.com/metric-bolts-maximum-torque-d_2054.html
If the threads are lubricated you knock off ~30%. For M8s it looks like close to 30Nm dry, a bit over 20 if lubricated.
The max torque you can apply with a screwdriver handle is about 10 Nm. Best use a torque wrench to at least calibrate your tightening every now and then. You're not going to get m8 bolts tight enough with just a handle, you'll need some sort of leverage extension.
www.researchgate.net/figure/Maximum-torque-a-person-could-produce-on-a-handle-significantly-varied-for-the-handle_fig3_51698033
Yeah , but keep in mind , those figures are probably for mild steel . Torqueing up a bolt stretches it , keeping the preload of mating surfaces . A lubricated thread will create more tension , not less , on the bolt because you have less friction turning it causing more preload of mating surfaces . A lubricated thread will unwind itself more easily but it would have to be very loose to do that . For a bolt to unwind it would have to be rattly loose . One of two things would have to happen , 1 , the bolt has stretched too much and wont stretch back , or , 2, the thread is wearing , most likely in the hole and is about to pull out . Aluminum is much softer and prone to wear . That's if your screwing into aluminum of course . So if its only 20 nm for lubricated bolts into mild steel , I would think 10 nm lubricated into aluminum would be about right . The same for brass or stainless inserts in carbon parts . I wouldn't overtighten into aluminum or you'll flog out the thread . Also stainless bolts are softer , weaker , stretchier and wont hold tension as steel bolts .
2 cents worth from an engineers point of view .
Select to expand quoteImax1 said..Ian K said..OldGuy3 said..
No need to over torque to keep thing tight.
Only yesterday I stumbled across an engineer on the internet talking about torque and loosening of bolts.
The primary purpose of torque is not to prevent them coming loose but to preload the mating surfaces. If an engineer selects M8 bolts then he intended them to be torqued to spec.
www.engineeringtoolbox.com/metric-bolts-maximum-torque-d_2054.html
If the threads are lubricated you knock off ~30%. For M8s it looks like close to 30Nm dry, a bit over 20 if lubricated.
The max torque you can apply with a screwdriver handle is about 10 Nm. Best use a torque wrench to at least calibrate your tightening every now and then. You're not going to get m8 bolts tight enough with just a handle, you'll need some sort of leverage extension.
www.researchgate.net/figure/Maximum-torque-a-person-could-produce-on-a-handle-significantly-varied-for-the-handle_fig3_51698033
Yeah , but keep in mind , those figures are probably for mild steel . Torqueing up a bolt stretches it , keeping the preload of mating surfaces . A lubricated thread will create more tension , not less , on the bolt because you have less friction turning it causing more preload of mating surfaces . A lubricated thread will unwind itself more easily but it would have to be very loose to do that . For a bolt to unwind it would have to be rattly loose . One of two things would have to happen , 1 , the bolt has stretched too much and wont stretch back , or , 2, the thread is wearing , most likely in the hole and is about to pull out . Aluminum is much softer and prone to wear . That's if your screwing into aluminum of course . So if its only 20 nm for lubricated bolts into mild steel , I would think 10 nm lubricated into aluminum would be about right . The same for brass or stainless inserts in carbon parts . I wouldn't overtighten into aluminum or you'll flog out the thread . Also stainless bolts are softer , weaker , stretchier and wont hold tension as steel bolts .
2 cents worth from an engineers point of view .
yes , for the smaller starboard M6 screws i use 5 Nm for the wing, 4 for the stab.
after washing and drying i spray Inox MX5 on threads and fuselage. my oldest fuselage still looks pretty good.
I can almost guaranteethat if you load up, most of the bolts that come with production foils that are manufactured in China or Thailand, with 30nm they will snap off. I have managed to tear heads off 5 mm bolts with a small Allen key. I doubt most manufacturers have the resources to randomly test the hardware their suppliers provide them with. Just because it says titanium or stainless steel on the bolt doesn't mean that's what they are actually made off.
Select to expand quotestehsegler said..
Just because it says titanium or stainless steel on the bolt doesn't mean that's what they are actually made off.
I think the bigger problem is that inferior grades of stainless or titanium alloys are used. With stainless, that may be A2 instead of A4, which is not too terrible since mechanical properties are similar, and you may even notice the problem since the bolts rust a bit in salt water. With titanium, the issue is more severe. That's partly because the bolts are much more expensive, so there's more incentive to cheat, and partly because lower grade titanium screws can contain more oxygen, which makes it more brittle (news.berkeley.edu/2015/02/05/oxygen-titanium/). Seems there are at least 35 grades of titanium alloy (www.mj-metalproducts.com/Viewtd/titanium_alloys_by_astm_grade.aspx), and I bet that most companies never check which grade is actually used in their screws, if they even spec'd the grade.
You don't want to hard-torque screws with tapered heads going into tapered-hole carbon wings. Torque hand tight only. I have seen those carbon tapered holes split from too much torque on the screw. Hand tight is enough for my AFS and SAB wings.
You can torque tapered holes in aluminum, such as SS mast to fuse. Also, you can usually torque any flat fittings with or without a flat washer.
I don't see any of the manufacturers or their reps using a torque wrench in any of their assembly videos.
Select to expand quotesegler said..
You don't want to hard-torque screws with tapered heads going into tapered-hole carbon wings. Torque hand tight only. I have seen those carbon tapered holes split from too much torque on the screw. Hand tight is enough for my AFS and SAB wings.
You can torque tapered holes in aluminum, such as SS mast to fuse. Also, you can usually torque any flat fittings with or without a flat washer.
I don't see any of the manufacturers or their reps using a torque wrench in any of their assembly videos.
I have never seen torque values published by foil manufacturers and most of the tables on the net are for steel nuts and bolts with known properties.
Your best bet is to have a look at torque values printed on aluminium and carbon bicycle components and take it from there. The torque settings for the foil will want to be a bit less when you consider for example the stabilizer only has a few threads engaging the aluminium fuselage, fewer threads than what you would see in a bike stem or seat clamp.
The idea for using a torque wrench is to prevent stripping the tread which is not hard to do torqueing blindly by hand ; you would be surprised how little 4Nm is.
Once you have used the wrench a few times you get a good feel for it and can then do it by hand.
I believe the torque value is how much the bolt can take, they assume there's enough threads there to hold . One thing for sure you can't just believe the torque figure, I've seen many bolts or components strip before the torque is anywhere close.
the face plate of the that bike stem will go before the bolt does.
Select to expand quoteBen1973 said..
I believe the torque value is how much the bolt can take
They should specify but if not you'd assume the torque to give the "typical clamp load" is what they'd give you 
Select to expand quoteBen1973 said..
I believe the torque value is how much the bolt can take, they assume there's enough threads there to hold . One thing for sure you can't just believe the torque figure, I've seen many bolts or components strip before the torque is anywhere close.
the face plate of the that bike stem will go before the bolt does.
Torque value is not 'how much the bolt can take' it is the quantifiable amount the manufacturer wants you to torque in order to avoid damage to the parts. The breaking strain of the bolt is 'how much the bolt can take' e.g moderate high tensile bolts have 8.8 stamped on the head. If there is nothing on the head assume it's a rubbish soft 'butter bolt'. If it doubt swap out the bolts for quality ones from a quality supplier.
Agreed,
If you are concerned with your bolts change to 316 A4 stainless
All reputable bolt suppliers can supply a material test certificate verifying the material grade if you are still nervous, In my experience I have never come across a 'dodgy bolt'
Just change them out if you have any concerns
My foil bolts and screws are all A4, I only hand tighten, and what is interesting is the stainless steel screwdrivers I got have different size handles for the Philips #3 (big handle) versus the Torx #30 (small handle), and so the handle size limits how much hand torque I can apply.
The other thing is be observant of the screw tension at the end of the session. If they are loose you either did not tighten enough or something else is loose causing vibration.
AFS included a Torx #30 screwdriver with their foil, the screwdriver handle had rubber ridges running along the grip, I always tightened the screws until my hand started to slip due to those rubber ridges folding over. Never had a wing/stabilizer screw come loose. Unfortunately that screwdriver tip rusted overtime, that is why I got the SS screwdrivers.
If you can, leave your foil assembled, or at least in as few seperate parts as possible. Assemble with Vaseline between all joints and screws, wipe off excess. I've done some testing and normal Vaseline has great anti corrosion properties and easy to use, cheap too.
I leave my Naish foils assembled for months, no corrosion or seized screws. Just give each screw a tweak when you get to the beach.
Select to expand quoteairsail said..
If you can, leave your foil assembled, or at least in as few seperate parts as possible. Assemble with Vaseline between all joints and screws, wipe off excess. I've done some testing and normal Vaseline has great anti corrosion properties and easy to use, cheap too.
I leave my Naish foils assembled for months, no corrosion or seized screws. Just give each screw a tweak when you get to the beach.
Well I have to remove the foil from the board, so those two screws are always being inserted/removed, the front wings gets switched back and forth between the F1080 and F770, and so now I just remove the front wing after each session (3 screws), makes it easier to get in/out of the house. So that leaves the stabilizer which I leave attached (2 screws), and those get teflon taped threads which never goes bad.
But good to hear Vaseline works, the issue for me is it will collect sand like any grease or paste, and sand combined with grease turns into an abrasive mess.
Select to expand quoteboardsurfr said..stehsegler said..
Just because it says titanium or stainless steel on the bolt doesn't mean that's what they are actually made off.
I think the bigger problem is that inferior grades of stainless or titanium alloys are used. With stainless, that may be A2 instead of A4, which is not too terrible since mechanical properties are similar, and you may even notice the problem since the bolts rust a bit in salt water. With titanium, the issue is more severe. That's partly because the bolts are much more expensive, so there's more incentive to cheat, and partly because lower grade titanium screws can contain more oxygen, which makes it more brittle (news.berkeley.edu/2015/02/05/oxygen-titanium/). Seems there are at least 35 grades of titanium alloy (www.mj-metalproducts.com/Viewtd/titanium_alloys_by_astm_grade.aspx), and I bet that most companies never check which grade is actually used in their screws, if they even spec'd the grade.
Windsurfing friend IMHO over torques the stock Ti bolts the came with his set up. He thinks I under torque my bolts. Since they don't move based on a mark with a Sharpie, unless they rotated a perfect 360 degrees I tell him BS. Both his bolts sheared at the same time in about the same location. Then he blames the manufacture and replaces with some high end 6/4 Ti bolts from a known quality USA maker.
6/4 Ti has a lower sheer strength than 316 stainless. Which has a relatively low sheer strength for steel. 316 is still at risk of failure from over torque or if below water application subjected to crevice corrosion. On the sailboat. Sheared a properly bedded, deck mounted chainplate mounting bolt couple seasons ago. Why I would definitely grease and remove as normal maintenance if using 316 for our below water application. Teflon tape is probably adequate if using Ti. Just don't over torque. Also, over torque is probably not good for the insert threads.
I also use Inox MX4 (Lanox) and it seams to work well (no problems so far, 2 users of use).
The Inox product is Aussie made. WD-40 have now copied them with a "specialist" lanolin product.
I use Tefgel on joints that do not need to be undone on the beach, i.e - wings to fuselage. I use nothing on joints that are undone each session.
I mistakenly used it on my bolts in my deep tuttle box to the mast head. The Tefgel became compacted in the bottom of the bolt hole in the mast head and I couldn't screw my bolt fully into the mast head. I had to clean the compacted material out in order to get a secure fit.
Well now that I just use WD40 on the foil wing screws they all go in fine, was getting worried since any of the 3 screws would start to cross-thread in the one insert 3 out of 4 times.
