A nuke-proof repair method for stripped FCS screw threads?

[alexeyga]

Just got a used 2013 SS surfboard with one set screw thread stripped, my first repair attempt using the most common "fill the hole with epoxy and re-thread"-method came out so-so... It will hold for the next couple of fin install/removals, but I surely can do better.

Which brings the main question of my topic - is there a better method of making a solid and long-lasting repair? I do remove fins between sessions - and since the whole FCS interface doesn't look like it was made to last (shame on you SS for switching from mini-tuttles) - I foresee a lot more repairs...(((

With that said I was thinking about 3 other possible solutions:
1)Stainless steel thread inserts
2)Stainless steel helicoil inserts
3)Go radical by replacing all fin-boxes with FCS-II

Only thing that worries me about #1 is that most thread inserts require re-drilling the hole to .375" - which i s lot over the original 9/64" and there isn't that much "meat" to begin with. I've seen some inserts that only require .281" hole, but I have yet to find these in stainless. Has anybody tried that solution already? Inserts of which length are required?

Thanks in advance for any constructive input guys!

[naishdude]

Just got a used 2013 SS surfboard with one set screw thread stripped, my first repair attempt using the most common "fill the hole with epoxy and re-thread"-method came out so-so... It will hold for the next couple of fin install/removals, but I surely can do better.

Which brings the main question of my topic - is there a better method of making a solid and long-lasting repair? I do remove fins between sessions - and since the whole FCS interface doesn't look like it was made to last (shame on you SS for switching from mini-tuttles) - I foresee a lot more repairs...(((

With that said I was thinking about 3 other possible solutions:
1)Stainless steel thread inserts
2)Stainless steel helicoil inserts
3)Go radical by replacing all fin-boxes with FCS-II

Only thing that worries me about #1 is that most thread inserts require re-drilling the hole to .375" - which i s lot over the original 9/64" and there isn't that much "meat" to begin with. I've seen some inserts that only require .281" hole, but I have yet to find these in stainless. Has anybody tried that solution already? Inserts of which length are required?

Thanks in advance for any constructive input guys!

Maybe not the best solution for you:
Take a thin tiewrap( nylon strap to put cabling etc together) put the tip of in in it and srew in the screw.cut off the rest sticking out..it will hold, as long as you do not take it out, and that is where it is not interesting for you.
Dude

[alexeyga]

Yeah, thanks, but I need something more "numerous fin-removal&installation"-friendly. As a temporary solution - a toothpick is probably the KISS wonder.

More I think about it and more an insert+longer set screw sounds like the best solution. Just need to find the appropriate model.

[SO_FL_Kiter]

Just saw you had already considered the helicoil option...

I have no experience with these in fiberglass, but that was where my first thought went. I've had great success with them in many other applications.

[alexeyga]

Yeah - thanks! Helicoil is another option that i'm considering as well - and given the nature of the application, it might actually be a more desirable solution to solid inserts. Solid setscrew+flxible helicoil in soft plastic VS solid setscrew+solid insert in soft plastic holding a piece under constant dynamic loads. To mechanical designer in me - helicoil sounds more... well... sound! )))

[robertovillate]

Can you re-tap to next size up set screw?

[Johnny Rotten]

I ripped the screws clean out of my probox, with a rock impact.

I sprayed the plastic with acetone to clean and improve the bond. I covered the screw in mold release then filled the hole with a paste like mixture of milled glass fibers and epoxy I reinstalled the screw and let it cure then twisted it out.

I don't know how "bomb proof" it is, but it was the best I could do. and its holding up.

The real problem is your likely overtightening the screw....go easy it doesn't need much

the area is a little small for helicoils and over size screws. you'll probably end up ripping out the screw the next time your board rolls if you remove too much material.

[alexeyga]

Thanks for sharing your experience Johnny, I actually had a chance to test my first repair - seems to hold for now and given that our season is basically over - I've got till spring to find a sound solution.

Here's a list of things I've seen so far that riders do and it works (in short term at least):
1)fill with epoxy+re-thread
2)M5 set screws (don't require any re-threading)
3)helicoils (there are some models made for aluminium with a rather small outside diameter - .281" or less).

Haven't found any feedback on threaded inserts at all.

Got really knowledgeable about fin systems... Still think that mini-tuttle is the best one out there, but unfortunately for board manufacturers - it is also the most robust one.

[SteveT]

I've had 2 boards with FCS stripped plugs and found a simple cheap and easy fix.
There is an extra Long FCS screw you can buy on EBay it picks up on the good thread above where the thread normally strips when over tightened at the base of the plug and has worked on both boards really well they tightened up nicely.
If you search FCS Extra Long Grub Screw you should find it but make sure they are Stainless Steel, I have also bought a couple extra screws so when I travel with my boards I swap a small screw for an extra long one as it's normally when your putting your fins in when you end up stripping a thread.
Hope this helps

[fpvSB]

You want time serts if longevity is what you want. That's what is used on the restored motorcycles and cars I've seen.