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Slot Box Thread Repair

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Created by shaggy696 > 9 months ago, 13 Feb 2017
shaggy696
WA, 78 posts
13 Feb 2017 12:17PM
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I hit my fin on the reef which partially pulled the front screw through the threads. It holds the fin in place but can not fully tighten as much as would like. Any suggestions on best way to fix?

Upon Google search I found this old thread.

Hooksey did you manage to fix?

Squid Lips
WA, 708 posts
13 Feb 2017 12:44PM
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If it were my board I'd rather use something like a Helicoil kit. You drill and tap a larger hole then wind in a new (stainless) steel thread to suit the original screw.

Mark _australia
WA, 23454 posts
13 Feb 2017 6:54PM
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What type? there is at least 3 types of screw inserts in slots....

MarkSSC
QLD, 642 posts
13 Feb 2017 9:55PM
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Helicoils are your best bet because they have the strength of the original thread. Permatex and Locktite make thread repair compounds but I don't think they will last. I tried it once on a table saw and got a short term result. Stick with the helicoil idea.

forceten
1312 posts
13 Feb 2017 10:28PM
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I would try a simple method first, the principle is the same for different screws, I would epoxy the hole and then redrill.

Mark mentioned screws, as different types, that's fact, most use self taping screws, several use grub screws which are like FCS screws, as in Simmer, they insert into a stainless steel housing with a internal hex head, if it were this type , one would probably need to remove the housing insert. Epoxy and retap with a self tap screw.

IMO, epoxy would be better than a helicoil, which you would need a thread compatible , unless they self tap.
Epoxy at any rate. The real bottom line may be replacement of the box entirely.

shaggy696
WA, 78 posts
14 Feb 2017 5:08PM
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Thanks all for advice

Select to expand quote
Mark _australia said..
What type? there is at least 3 types of screw inserts in slots....



mark from memory it looked like self tap but I am working away currently. It is a tabou if you know what they are.

i would of thought the suggestions on filling with resin or something should do the trick as there are still bits of threads still there. I have been still sailing it for past year or so with a matchstick jammed in between to swell in the water and keep tight.

P.C_simpson
WA, 1491 posts
14 Feb 2017 6:48PM
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what board is it in?

MarkSSC
QLD, 642 posts
14 Feb 2017 9:28PM
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Select to expand quote
forceten said..
I would try a simple method first, the principle is the same for different screws, I would epoxy the hole and then redrill.

Mark mentioned screws, as different types, that's fact, most use self taping screws, several use grub screws which are like FCS screws, as in Simmer, they insert into a stainless steel housing with a internal hex head, if it were this type , one would probably need to remove the housing insert. Epoxy and retap with a self tap screw.

IMO, epoxy would be better than a helicoil, which you would need a thread compatible , unless they self tap.
Epoxy at any rate. The real bottom line may be replacement of the box entirely.


I disagree in a friendly way. Even with the epoxy you would have to drill and tap using the right size drill and thread size. Helicoil safe widely used so the right type should be easy to find...no harder than finding the correct size tap to cut the thread. Stay clear of self tappers because they are usually associated with non structural applications ie. they lack the strength in these sort of jobs

Mark _australia
WA, 23454 posts
14 Feb 2017 7:32PM
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If a matchstick is doing it yeah I'd go ;
Wax screw with shoe polish (as in Nugget / Kiwi not the liquid with a sponge stuff schoolkids use!!)
Clean hole out goodly with acetone and cottonbud
Fill it up with a metal filled epoxy. Try not to use the 5min ones, 24hr waaayyy better.
Run the screw in and leave it
DONT leave epoxy on the head of the screw, wipe it off, lest you entomb it forever

After removal any excess should eb able to be filed out of the box

It won't work if it it fully stripped but if a match has been working I reckon you're rigght

shaggy696
WA, 78 posts
14 Feb 2017 8:11PM
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Select to expand quote
P.C_simpson said..
what board is it in?


Taboo twister

shaggy696
WA, 78 posts
14 Feb 2017 8:14PM
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Select to expand quote
Mark _australia said..
If a matchstick is doing it yeah I'd go ;
Wax screw with shoe polish (as in Nugget / Kiwi not the liquid with a sponge stuff schoolkids use!!)
Clean hole out goodly with acetone and cottonbud
Fill it up with a metal filled epoxy. Try not to use the 5min ones, 24hr waaayyy better.
Run the screw in and leave it
DONT leave epoxy on the head of the screw, wipe it off, lest you entomb it forever

After removal any excess should eb able to be filed out of the box

It won't work if it it fully stripped but if a match has been working I reckon you're rigght


Cheers mark sounds like a simple way that would at least be worth trying.
It is only the front screw I need to do it on. The back still holds fine.

forceten
1312 posts
15 Feb 2017 3:10AM
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Select to expand quote
shaggy696 said..
P.C_simpson said..
what board is it in?


Taboo twister


So we now know that the slotbox is made by Cobra, and yes you are probably correct they are self tap.

forceten
1312 posts
15 Feb 2017 3:24AM
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Select to expand quote
MarkSSC said..
forceten said..
I would try a simple method first, the principle is the same for different screws, I would epoxy the hole and then redrill.

Mark mentioned screws, as different types, that's fact, most use self taping screws, several use grub screws which are like FCS screws, as in Simmer, they insert into a stainless steel housing with a internal hex head, if it were this type , one would probably need to remove the housing insert. Epoxy and retap with a self tap screw.

IMO, epoxy would be better than a helicoil, which you would need a thread compatible , unless they self tap.
Epoxy at any rate. The real bottom line may be replacement of the box entirely.


I disagree in a friendly way. Even with the epoxy you would have to drill and tap using the right size drill and thread size. Helicoil safe widely used so the right type should be easy to find...no harder than finding the correct size tap to cut the thread. Stay clear of self tappers because they are usually associated with non structural applications ie. they lack the strength in these sort of jobs


If the damage is restricted to 'just' the hole, your coil , along with the drill kit , could very well work. You would need to drill a precise hole into a very narrow area, a larger hole than the coil, insert coil , after making certain it doesn't extend into the cassette cavity, you also need like you said a new screw, that has a head that will recess into the hole, don't think you want it sticking up any.

If the surrounding area , that around the hole is damaged, your coil does nothing to reinforce that.

There is more than one way to bake a cake.

The slot box has inherent weakness, this is the worst, screws that get pulled out or stripped. It's designed for multifins to save weight, length not so long, twin size typically.Some freestyle boards use it as a weight saving measure, pure bullcrap that.

Starboard have a , 2 or 4 times improved version , Starbox, I think it's called now current using USBox fins and slots with some mod.

To date the best strongest slot box is from Flikka, using G10 inserts to hold the screws, and using internal hex head screws, all components made in house.

The majority of structure on slot box fins, is the fin being held in the fin base cassette, the screws secure it to the other side, unless it's a Witchcraft , who have screws on both sides.



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"Slot Box Thread Repair" started by shaggy696