I have a bit of an on-going saga with my footstraps on my 2020 Fanatic Blast. In short I've always found it very difficult to tighten the straps because the screws are so difficult to turn. I have the proper screwdriver (#3 PH), and I'm no stranger to working with tools being a mech eng, doing my own car repairs, bike repairs, making boats, etc. It turns out (apparently) that my board was shipped with the wrong screw size, a 7mm thread forming screw. This took me 1.5 years to figure out after finding this: forum.fanatic.com/d/27111-blast-undersized-hole-update
So I bought some 6mm "cobra" screws from Chinook, which are said to fit most boards including Fanatic.

The 6mm screws from Chinook have a different thread pitch than the 7mm screws so I'm now at a crossroads (there are actually two standards for plastic forming threads so there are at least 2 different pitches for each of 6mm and 7mm). I can keep using the 7mm which are too big and may have already cross-threaded the plugs, or I can switch to 6mm. But I'm not sure it makes sense to put the 6mm in a plug that previously had the 7mm because of the different thread pitch. I can currently make either thread work but I'm worried that eventually the threads will get thrashed. Given that this board is the third most expensive thing I've ever purchased (admittedly a very distance third behind a house and a van), it drives me nuts that these threads could be getting wrecked through no fault of my own.

Maybe someone else with a 2020 Blast can let me know if they have 6mm or 7mm screws. At this point I have zero confidence in knowing what size and pitch of thread these plugs were actually designed for.
Any advice on what to do? Keep the 7mm? Go to 6mm? Drill out the plugs with a 7mm drill bit and hope I don't go through the bottom?

stick with the 7, the 6 is not gonna work once you've put the bigger one in. Greese the bolt (heard washin gup liquid works well) and just tighten them up

Oh boy. Mast bend business.., now screws. I saw some interesting stuff but I never in all my 15 years of windsurfing encountered this. I saw longer screws which can be cut but no different diameter and thread step ones. Frankly I never purchased any screws. I have 5-6 spares I accumulated through my windsurfing 'career' LOL. Thankfully they are stainless.

If I were you and still wanted to use standard, I would take some clear Gorilla glue put a few drops into each hole sprinkle with water and screw in 6mm screws. Gorilla glue is not like epoxy and hardens to hard rubber so you should not have problems unscrewing. You can also try to wrap each 6mm screw with white thread teflon tape . Then unscrewing will be like a walk in the park.
I used teflon tape wrapped screws a few times to build dif diameter threads in carbon foil masts with carbon powder and epoxy. Works amazing.

Just a tip for getting the screws in. Lubricate them......some soap or i have even used olive oil. makes it SO much easire.

I realize you may have already done this, but make sure screws are not a fraction too long and hitting the bottom of the hole, also it could be that the core diameter of the 7mm is too tight in the hole (i have seen this before myself) and if that's the case you will have to go back to 6mm ones unless you drill the hole bigger
What I would do is play with one hole on board in spot you would not ever use the strap in

I carry a cake of soap and use it on the screw thread if they are tight, same as i do with fitting a fin of foil mast to my tuttle box
Seek help from a friend if required because it sucks if you strip the holes out

I recommend looking up this issue with the Fanatic forum. Apparently on some boards they mis drilled the final step and the holes are undersized. It was a PITA on my blast. Craig from fanatic says it is ok to drill them out just slightly to get the screws to fit properly, but it's worth searching for that thread.

I ended up finding replacement screws with pure luck and they fit perfect. I didn't want to drill it out so I'm thankful I found the right size screws by chance.

This all makes sense as only two brands changed to 7mm screws - Fanatic and Starboard. In the transition time its hardly surprising that Cobra drilled some holes too small as they were doing 20 other brands with 6mm screws.

The minor diameter on the normal M6 screw is 4mm. In my boards, I drill the inserts with an imperial bit that works out to 4.2mm. Dunno what gauge or what fraction it is, but Smish it seems you're used to doing those kinda things so it will be easy for you. Just find the imperial bit that's a tiny bit larger than the minor dia on your 7mm screws and carefully redrill all the inserts
Sorry for the suck eggs part but not too deep, there is only about 5mm plastic at most in the bottom of the inserts
Or, better yet buy a handful of 'normal' Cobra style M6 screw, see how they work, If they every pull out, then do the above....?

As Mark says , be careful not to drill too deep . A sharp drill will suck down the hole and out the other side real quick .
Ill be using twin screws next build .

I recently bought a board in pristine condition, only sailed a couple of times since new. But I couldn't for the life of me get the footstraps tight. Can you see why? (Maybe same issue for you.)

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mikey100 said..
I recently bought a board in pristine condition, only sailed a couple of times since new. But I couldn't for the life of me get the footstraps tight. Can you see why? (Maybe same issue for you.)

Yes, I've already implemented the "screw is too long" solution: www.seabreeze.com.au/forums/Windsurfing/General/Tightening-footstraps-2

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aeroegnr said..
I recommend looking up this issue with the Fanatic forum. Apparently on some boards they mis drilled the final step and the holes are undersized. It was a PITA on my blast. Craig from fanatic says it is ok to drill them out just slightly to get the screws to fit properly, but it's worth searching for that thread.

I ended up finding replacement screws with pure luck and they fit perfect. I didn't want to drill it out so I'm thankful I found the right size screws by chance.

The forum is where I learned about the wrong size issue. One of my concerns is about the thread pitch. I could drill the holes to fit 7mm but what thread is in the plug? The 6mm and 7mm threads could be completely misaligned from each other. I don't suppose you know the pitch of the replacement screws you have? And where did you get them?
cheers!

If you checked that the length is right maybe you can try this to make the hole a tiny bit bigger: get a piece of 100-120 grit sand paper and roll it until it is the diameter of the hole. Cut the roll an inch longer than the hole and put it in the drill. You have created a file that will eat very little at a time. I think you just need to remove very little material for the screws to move a little bit more freely. You can also try with coarser grit. I have never done that but it should work and should be very safe (not drilling through or over bore it).
you can even glue a piece of sandpaper to a thin wood dowel or similar (even the shaft of a drill bit?) as long as it fits almost snug it should remove material.

The holes have no thread until a screw cuts it. I don't think you will have an issue with pitch. Again, if the M6 ever loses bite, drill and use M7

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shmish said..

mikey100 said..
I recently bought a board in pristine condition, only sailed a couple of times since new. But I couldn't for the life of me get the footstraps tight. Can you see why? (Maybe same issue for you.)

Yes, I've already implemented the "screw is too long" solution: www.seabreeze.com.au/forums/Windsurfing/General/Tightening-footstraps-2

Well done for your " Yes, I've already implemented the"screw is too long" solution" Mr Shmish. But, I do note that your referenced link above, in fact links to a separate thread from 9 months ago (titled "Tightening footstraps") to the one that my referenced reply was contained in. Sadly, I had not seen your multiple posts in that 'other' thread. I am truly and deeply sorry if my above post and accompanying photograph, which was done with only the purest intention of offering an opinion as an offer of help to you as creator of this thread, has offended you to such a degree that you have felt so strongly so as to feel the need to make comment and supply all and sundry on this forum with a direct link to your comment on that 'other' thread.
I have obviously, inadvertently and erroneously thought the point that you were trying to make in your so eloquent a post in 'this' thread was the fact that you had replacement screws that were of a different thickness (6mm and 7mm, as in the photograph you supplied) and to which you referenced no less than five times in your previous post within 'this' thread), whereas my post, (also with photograph supplied) was a graphic depiction of two screws that were the SAME thickness but which were clearly and obviously very different in length, something which I did not see as being so obviously evident in your supplied photograph or noted in your earlier post in this thread. On a subsequent review of your supplied photograph, I can now observe that the two screws in your photograph are indeed of different length, an observation that I had not made on my previous viewing. How silly of me!
Again, my sincerest and most heartfelt apologies for any grief I may have caused you in this serious matter. Good luck in solving your 'screw' issues which appear to have plagued you for such a long time..
Cheers.
P.S. I obviously have too much time on my hands now that I have retired.

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mikey100 said..

Hi Mikey, I'm super sorry, I really didn't mean it like that. I was just a bit rushed and wanted to get some responses in before I left for work. I absolutely appreciate you (and everyone) taking time to respond. I can't even remember how I used to solve problems pre internet and web forums, and I always try to be helpful and respectful. I hope you believe I'm being honest about this.
cheers

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shmish said..

mikey100 said..

Hi Mikey, I'm super sorry, I really didn't mean it like that. I was just a bit rushed and wanted to get some responses in before I left for work. I absolutely appreciate you (and everyone) taking time to respond. I can't even remember how I used to solve problems pre internet and web forums, and I always try to be helpful and respectful. I hope you believe I'm being honest about this.
cheers

All good. Cheers.

Who would have thought strap screws topic has so much heat . Lucky the topic wasn't vent plugs .

You can use the thinner screws so long as they are still fairly firm to setup. The last 1/8~1/4 of turn should be fairly tight. Use my anti twist trick and you'll be good to go for a while.

Straps and pads will set in and require additional tightening after the first session(s). Then, check them every once in a while. Normally straps will start twisting when the screws get loose so watch for that.



PS: last few years fanatic straps will twist no matter how tight because of their non slip (but still slip) design. All of the rental center straps here twist...

I bought a slightly used Fanatic board that had 7mm footstrap screws. Ugh! I removed those and used 6x25 thread forming screws in the same holes. They work fine. What is important is to ditch the phillips heads and go with something like torx or square drive, or even hex. They don't slip.

I use torx. With a bench grinder you can remove the sharp pointy tips.

Ugh, I'm kind of an idiot on this one. I know that the footstrap plugs use thread forming screws and I know what thread forming screws are. Yet for some reason I got it in my head that the plugs were also pre-tapped to some extent. I didn't even think to look at some of the holes that I had never used. And of course, they are just straight bores.

So the best solution for me was to drill the holes, since I had already formed threads in several holes. These screws are "Delta PT" and the pre-tap drill size is 0.8 x nominal diameter. So 0.8 x 7 = 5.6 mm = 0.220" which is very close to 7/32". So I drilled them with a 7/32 bit. Luckily I used a jig of sorts to restrict the drill depth. The thermoplastic really wanted to grab the drill bit and pull it down.

Thanks for all the replies.