Fixing a Deficient Liner Lock

G

Greggy

Joined
Feb 4, 2022
Messages
549
Recently received a liner lock knife. The issue is this. The liner lock bar insufficiently engages the landing pad on the blade body. Only about 1/3 to 1/2 of the liner bar actually engages the blade landing pad and only about 20% of the blade landing pad is covered by the liner lock surface. As a result, when I tap the back of the opened blade against a table, the lock gives and the blade tries to close. This happens about half the time, with the blade holding up the other half. Not acceptable and unsafe.

Question. I intend to take a micro file to either the liner lock contact surface or the landing pad surface on the blade body. The latter is slightly angled so that the force of the liner lock tends to push the blade firm against the blade stop. This I understand. Is a micro file the answer? I suppose that I only need to take 1/1000 of an inch or thereabouts off the surface. My inclination is to lightly file the blade body angled landing surface. This will allow the liner lock to push further into the blade and to better engage the blade.

Any thoughts or advice is appreciated. Thanks.
 
If it was cheap, I say go for it. If it was pricey, send it back.
 
jlauffer said:
If it was cheap, I say go for it. If it was pricey, send it back.
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A $60 knife, which to me is intermediate priced. I have no problem working on it, but am wondering if there is a better way other than returning the knife.Thanks.
 
I’d try to adjust the liner lock tension by taking the knife apart, noting where the lock bar is stationed and bend it in a tad bit. That will let you know if there’s room for the lock to travel over some. If it causes lock stick without moving over into the blade more, then it is a manufacturer mishap.
Remember, once you do anything to the knife, it’s yours.
 
Greggy said:
Recently received a liner lock knife. The issue is this. The liner lock bar insufficiently engages the landing pad on the blade body. Only about 1/3 to 1/2 of the liner bar actually engages the blade landing pad and only about 20% of the blade landing pad is covered by the liner lock surface. As a result, when I tap the back of the opened blade against a table, the lock gives and the blade tries to close. This happens about half the time, with the blade holding up the other half. Not acceptable and unsafe.

Question. I intend to take a micro file to either the liner lock contact surface or the landing pad surface on the blade body. The latter is slightly angled so that the force of the liner lock tends to push the blade firm against the blade stop. This I understand. Is a micro file the answer? I suppose that I only need to take 1/1000 of an inch or thereabouts off the surface. My inclination is to lightly file the blade body angled landing surface. This will allow the liner lock to push further into the blade and to better engage the blade.

Any thoughts or advice is appreciated. Thanks.
Click to expand...
If you are going to do this, do it on the tang, and don't use a file. Use a fairly fine grit stone with flat surface, such as a Norton India stone. Go a bit at a time, check the fit and action, repeat as needed. Done carefully you'll keep the proper lock interface geometry and maybe improve the lock action by smoothing out the face on the tang.
 
I'd send it back, it's easy to screw it up even more. Liner lock interfaces can be difficult to get right. What kind of knife is it, if you don't mind?
 
Arathol said:
If you are going to do this, do it on the tang, and don't use a file. Use a fairly fine grit stone with flat surface, such as a Norton India stone. Go a bit at a time, check the fit and action, repeat as needed. Done carefully you'll keep the proper lock interface geometry and maybe improve the lock action by smoothing out the face on the tang.
Click to expand...
This is what I am thinking. About the comments above, I did take apart the knife and examine and clean/lubricate. I slightly bent the lock bar to increase tension and put the knife back together. This did not help much. But it did increase the tension on the detent when closed. I was careful and barely applied pressure on the lock bar, so no big change here. I have to admit that this is fixable and am looking forward to a project. But, I will wait and sleep on it. May still return it and am aware that once I attempt the repair the knife warranty is void. No big deal, it is only a $60 knife.
 
jux t said:
I'd send it back, it's easy to screw it up even more. Liner lock interfaces can be difficult to get right. What kind of knife is it, if you don't mind?
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I was going to not mention make and model. But why not. It is a Kizer Horn.
 
Its not really hard to do, it just takes a lot of time and patience. You'll need to re-assemble-disassemble-re-assemble a few times, checking the engagement and the geometry often, making sure the angles are maintained and the lock face stays flat, until you get it to work. Once you get it right the lock should work better than new.
 
Arathol said:
Its not really hard to do, it just takes a lot of time and patience. You'll need to re-assemble-disassemble-re-assemble a few times, checking the engagement and the geometry often, making sure the angles are maintained and the lock face stays flat, until you get it to work. Once you get it right the lock should work better than new.
Click to expand...
I am used to detail work, so it doesn't intimidate me. Still going to sleep on it. Thanks.
 
Arathol said:
Its not really hard to do, it just takes a lot of time and patience. You'll need to re-assemble-disassemble-re-assemble a few times, checking the engagement and the geometry often, making sure the angles are maintained and the lock face stays flat, until you get it to work. Once you get it right the lock should work better than new.
Click to expand...
Agreed, but need to be careful. It will wear over time, so it can go from what you thought was "just right" to "too much" pretty quick.
 
If it is a custom, some makers will take it and make it better. And some will not.
 
jlauffer said:
Agreed, but need to be careful. It will wear over time, so it can go from what you thought was "just right" to "too much" pretty quick.
Click to expand...
I will bias my approach more towards taking too little off as opposed to too much. If I decide to go for it. I appreciate all the advice. I am new here and this site is a great resource.
 
Mass manufactured makes me lean toward immediate return to the vendor; they should cover you. Emphasis on should, of course.
 
If you bent the lock out more, I'd say it's yours but if you explain things to Kizer or the dealer, they might still take it back. Any knife that has lock failure shouldn't have left the factory at all. It's Kizer's bad here. Before you try anything though, I'd just flip it a couple hundred times. Sometimes it'll just break in. If not, I'd do what the others said. Go slow and check constantly. Don't be surprised if it develops lockstick but at least that makes the lockup stronger. Can't be any worse than it is right now.
 
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