Question About Fixing Up & Down blade play in a Lock Back Folder…

S

sh00ter01

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Sep 26, 2007
Messages
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So I have a used and abused Cold Steel Gunsite II folder that has developed some noticeable vertical blade play. The lock still holds strong without fail and there’s negligible side to side play, but I find the excessive up and down quite annoying.

Is there anyway to correct this?

I was thinking of welding a small bead on the face of the lock bar and grinding it back down to a tight fit, but here the kicker, the knife is riveted together and I only have access to a mig welder which would probably get things to hot.

Anyone have other possible solutions that can be done knife intact? Any help would be appreciated:thumbup:

A pic of the blade in question (it was reground to eliminate edge damage and Cold Steel’s god awful serrations)
1307471536.jpg


Thanks
-sh00ter
 
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Another possible solution I've thought up is to use a staking tool to knock some material from either side of the lock bar into the gap between it and the blade. I have no idea how this would hold up or if it would even work because of the hardness of the lock bar.

Generally speaking, are the lock bars hardened close to the blade RC or are they softer?

I realize that some up and down is normal for lock back designs, but this is excessive and I'd like to bring it back to an acceptable amount.

Any help or advise would be appreciated:thumbup:

Thanks
-sh00ter
 
Add some thin layers of superglue on the lockbar surface? Need to be careful not to use too much & spread it to the sides.

Or add thin aluminium foil strips to it. Never tried before, just some ideas.

Add test
I have a different problem on my Navy k631. When open, the lockbar goes a tiny bit deeper, although no up/down play, but the end of the lever where you press to unlock just a bit too high & not flushed to the handle.

Added 2 layers of normal transparent tape (office supplies) to the lockbar surface that takes the pressure when cutting or flicking open (acts as stop pin). Now it locks up as tight, but the engagement is just nice that the lever doesn't jut out anymore.

I guess this is one of the problem Demko solves with Tri-ad lock.
 
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You have either worn or bent the blade pivot pin. Replacing it should tighten it back up. Make sure the new pin is a very tight fit in the blade.

If there are other problems, you should see displaced metal on either/or the blade or lockbar.
 
Chris "Anagarika";10115192 said:
I guess this is one of the problem Demko solves with Tri-ad lock.
Click to expand...

Indeed it is:thumbup:

Bill DeShivs said:
You have either worn or bent the blade pivot pin. Replacing it should tighten it back up. Make sure the new pin is a very tight fit in the blade.

If there are other problems, you should see displaced metal on either/or the blade or lockbar.
Click to expand...

No displaced metal, so I guess the pin may be worn/bent (wouldn't surprise me with all the abuse:D).

Any tips for replacement? Know anywhere to get more rivets? Or a place to pick up an adjustable pivot that would fit after drilling out the existing rivet?

-sh00ter
 
File the head off the existing rivet, and drift it out.
Chuck a common nail in a drill and file it to exactly the proper diameter. Use it for the pivot. File the ends square, with 1/16" protruding on either side. Place on an anvil of sorts and gently peen one side. Use a very small (tack hammer or smaller) hammer and short, light taps. You want to deform the end of the pin only. Turn the knife over and repeat. Swap sides peening, until the blade is snug.
 
I think I'm gonna pick up a barrel and screw set and try going that route in terms of replacing the pivot (it'd be nice if it was adjustable as well). Hoping that Cold Steel used a standard 3/16 hole for their pivot in the older voyagers. Anyone know if they did?

Bill DeShivs said:
File the head off the existing rivet, and drift it out.
Chuck a common nail in a drill and file it to exactly the proper diameter. Use it for the pivot. File the ends square, with 1/16" protruding on either side. Place on an anvil of sorts and gently peen one side. Use a very small (tack hammer or smaller) hammer and short, light taps. You want to deform the end of the pin only. Turn the knife over and repeat. Swap sides peening, until the blade is snug.
Click to expand...

If all else fails, I will fall back on your suggestion:thumbup:. Any brand of nail better then others (I want to be able to beat on this thing like I always have)?

-sh00ter
 
Chris "Anagarika" said:
Add some thin layers of superglue on the lockbar surface?
Click to expand...

I was searching today (or technically yesterday - I work the afternoon shift) before work for an answer to this, because my new Large Espada G10 in Aus10a had some slight blade wiggle up and down out of the box. I looked at the tang and lockbar to see if I could figure out how to fix it with a file, but the play was just too slight and nothing obvious jumped out at me, hence the search. I noticed the suggestion quoted above, and wanted to mention that I can vouch for its efficacy, at least in a case where I did something very similar. I recently modded a Voyager to a wharncliffe (or lambsfoot?) and then tried to make a pair of G10 scales for it. Well I misaligned some of the holes ever so slightly, and the notch in the tang of the blade did not mate up with the stop pin perfectly. It locked open, but then seemed to grab the stop pin, refusing to close again. Among the fixes I attempted were grinding slightly inside the notch in the tang. This seemed to work, but the action had already become sloppy from other fixes along the way in the scales, that I withdrew, and reassembled the knife back into the aluminum and FRN handles from the factory, then shaped them as closely as I couldto what I wanted to do with the G10 handles. Long story, longer, everything fit back into place, but there was (foreseeable [facepalm!]) up and down balde play due to my molestation of the notch in the tang. I figured I'd already ruined the knife, so why not true some Gorilla glue cyanoacrylate in there to see if it helps? One drop, not even very precisely placed, dried overnight, and guess what: bank vault lockup!

How long it will last is another question, as this happened only a week or so ago, and I think it is deteriorating a bit; the knife has been flicked open aggressively quite a bit over the last week. But the knife is functional, even with possibly microscopic play. If it gets worse, I can always do it over again. I hope this can help anyone else out there with a "ruined" knife.
 
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