Sanding liner to help with blade catching on close?

[lithicus]

So, I never knew this section existed and this is my first post here. Probably a few other posts of mine should've been here as well.
I'm not super experienced, but I have tightened a few blades up in a vise, peened the pin, and sanded it down before. I've also fixed blade centering on a knife or two when it was easy enough.

Anyway, I just got a 1974 Case medium stockman. I am super happy with it, but there is one problem. About half of the time, when I snap the pen blade opposite the sheepsfoot and clip closed, it snags on the liner and hangs / doesn't close completely. It's odd that it only happens sometimes as there is no blade play on any blades with this knife as far as I can tell. It seems to catch about halfway down the pen blade edge. It's actually started to bite pretty good into the brass liner as the liner now has a sharp "sticker" if you run your finger down it. I already VERY lightly sanded (2000 grit) the "sticker" so I can't catch my finger on it and hurt myself on accident. But, it will still catch on occasion if I let it snap shut as opposed to guiding it into the blade well gently avoiding the liner.

As I said, I have fixed blade centering on some other knives in the past, including one stockman. But, on that stockman, the only thing I fixed was the clip blade centering and it had blade wobble on that side that needed fixed anyway. This knife scares me because if I try to center the pen, odds are it's going to catch the sheepsfoot and then I'd have to center that too. There is enough room between the sheepsfoot and clip to do this, but I'm worried I would introduce blade play which I would prefer not to have to fix. I obviously can't / don't want to send this back to Case; can't imagine it getting any better while keeping the original parts.

I was thinking about a simpler solution. And so, I guess my question is... might it be possible for me to continue sanding the liner at the contact point to make some room for the pen? Maybe thin the pen out some too? It seems like a simpler fix that is less likely to introduce mechanical issues with the knife. But, I also feel like I may not be able to remove enough material to really fix the problem.

Worst case scenario, I just leave it as-is and close the pen blade very carefully But, I'm a tinkerer and if I can fix this without making things much worse, I'm all for it.

Much appreciate everyone's advice! Thanks!!

 

[Obsessed with Edges]

Some pics, close up, of the affected liner & blade edge, and the spacing between the liners & other blades might shed some light on what might work.

First thought that occurred to me was, just a tiny bit of sharpening on the blade edge catching the liner might be enough to change how the edge contacts the liner - OR, if it does make contact, it might just make it deflect off the edge's bevel, instead of impacting the apex of the edge itself and catching. Sometimes contact issues between blade & liner, or between blade & backspring can be changed with just a tiny bit of sharpening.

But again, some pics of the situation might make things clearer for gathering useful feedback.

 

[lithicus]

Yea, should've put pics to begin with Almost always better than not having them. I don't have the best equipment for photography... so, I did my best. Although, looking at some of these pictures and inspecting the knife more, I'm not sure if sanding the liner / thinning the blade will work. The most odd thing to me is how well the blade sits when it doesn't hang. Seems to be plenty of clearance between the pen and the liner... not sure what's up with that.

Here are some pics of the pen blade hung up. You can also see some of the blade spacing good in this picture.

Here is a pic with just the pen blade fully closed and not hung up. If you look closely, it seems like there's adequate spacing... very odd to me.

All blades closed. It's a stockman so it's always a tight fit. The tip of the pen is not bent, it's just the lighting. The clip is fairly well centered too which leaves less room to move the sheepsfoot/pen.

Lastly, two pics showing the liner only where it is catching. It's obviously going to be the bright spot inside the circle.

 

[lithicus]

I dunno.... in that third pic is almost looks like the liner is bent inward? I'll have to check it with my calipers to be certain. The gunstock pattern creates kind of an optical illusion when trying to sight down it.

 

[old4570]

Hmmmmmmmm ........................

1) Bevel the liner and polish it ..
2) Bend the blade very gently ...

I would try cleaning / bevelling / polishing the liner first ...

Trying to bend the liner outward ? .......................... ?

 

[lithicus]

0.213" by the pen tang
0.203" by the clip/sheepfoot tang
0.192" where the pen catches the liner

This is a new one for me lol Do I try to somehow bend that liner back out?

 

[lithicus]

Hmmmmmmmm ........................

1) Bevel the liner and polish it ..
2) Bend the blade very gently ...

I would try cleaning / bevelling / polishing the liner first ...

Trying to bend the liner outward ? .......................... ?

I think you might be onto something with beveling and polishing the liner. And also trying to bend it outward somehow. After taking some measurements and looking at those pictures more closely, it certainly seems like somehow that liner got pushed/bent inward. Haven't read/seen much on doing that, but I imagine it would be fairly straight forward.

 

[old4570]

Problem is , you would be pushing against the scales + the middle liner ..
You might fix it ? Or make it worse ? By trying to bend the liner out again . It's tricky .. Might be ok ? Might not ?

If you bevel and polish the liner in question , the blade should not hang up on it ! ( Least risky option )
Nuff Said !

 

[lithicus]

Yea, since my comment I've been thinking about it and bending that liner out is far from straightforward. I'd presume the backsprings kept things even down on the bottom of the knife and that the liner is only "bent" up top. But, bending the whole liner back with a jig and a vise would put stress on the pins. You'd really only want to "bend" the top out, but that'd still put stress on the bone. I'd have to bend it past "center" so it would return to a proper position when the pressure was released... I can think of a few ways to counter some of these issues but the more I thought about it the riskier it became. I'm still thinking about different approaches because I like critical thinking, but you're right. Don't over complicate things, especially at this stage in the game.

Bevel and polish the liner first, see how it turns out. Maybe even thin the pen blade or put an edge on it that'll help it deflect off the liner instead of grab it. Trying to crink the blades or bend that liner out is really a last resort as it could start to get destructive. I don't even use the pen all that often on stockmans so it's not the end of the world if I just have to be gentle with it.

 

[Bill DeShivs]

The blade is bent.
Bend it back.

 

[lithicus]

One thing I wanted to do was take a straight edge to the liner to try to double check things. Don't see any reason I couldn't do the same with the pen blade. It does kind of look like it might be bent in the first two pictures. And, my understanding is only the sheepsfoot should be bent/crinked on a stockman. So, I'd think the clip and pen should both be straight.

If I can get good pictures with a straight edge I'll post em here just for completeness sake.

 

[Obsessed with Edges]

I'm also thinking you should have enough room to slightly (gently, barely) bend the blade back inline. Shouldn't take much to keep it from catching the liner to the outside, while still leaving enough slip-space next to the adjacent blade to the inside.

I wouldn't mess with trying to bend the brass liner - you'd have to press outward against the bone cover, which could crack the bone.

 

[lithicus]

I'm going to follow this post up with another one including some more pictures. But, I do wonder if the slight blade bending/crinking might be necessary. I assume everyone here is talking about crinking the blade at the ricasso and not truly bending the blade. I've only crinked a blade two or three times on much cheaper knives, but I always did it like this:

I believe the video above is more or less how they do it in the factory, like in the GEC tour video (they just have a press, iirc). An annealed tang is arguably mandatory (?) for this to work well, or at least easily. But, last night, I was thinking about another video I had seen and was wondering why more people don't do it like this:

It would seem that using a jig in a vise like that would be less prone to introduce blade wobble / blade play as you're not banging on the pivot. Might even behave more like the press from GECs youtube tour? And, Felix actually makes this point in his video about this method not introducing blade play. My only guess is that the SAK wood saw is not hardened like a blade would be? And so, a hard cutting blade would be more likely to snap if you tried to do this with it? When I went back and watched Felix's video, I was quite surprised with how "springy" the saw appears to be!

Anyway, just something I was thinking about regarding "bending" the blade back. I'd probably go with the tried and true method in the first youtube link if it seems necessary after beveling/polishing the liner. Just have to take it real slow so I don't end up on the other side of things where it's closing on top of the sheepfoot. And certainly don't want a blade snapped in half. My biggest concern with crinking the blade away from the liner with the hammer method is introducing blade play and having to squeeze the bolsters in a vise, peen the pin, sand it flush, all without pinching the blade and affecting the action. Almost every time I've crinked a blade it ended up with some play that needed fixed. Maybe I'm missing something here?

 

[lithicus]

So, one thing I noticed is that most stockman's pen/spey blade looks to be sort of crinked toward the liner; which I found odd. Never noticed before. Also, makes me wonder how bad the blade being discussed really is. I do think after looking at these pictures that the blade we are discussing is further out of line than the others.

Here are 4 pictures. Sorry, I tried to make them smaller so they were easier to view. But, that didn't quite work well. I aligned the liners to a grid and cropped the image so that it should be easier to see how "straight" the blade is. First is a very new case medium stockman, then my old case medium stockman we are discussing, then a 34OT, and then a 35 cattle knife:


The all seem a little crinked toward the liner side, but I do tend to agree that the blade in question is the worst.

And FWIW, I noticed that the bone is actually separated from the liner a little bit where the liner is bent inward. It's hard to see, but I think you guys will pick up on the shadow inside of the circle.

So, I think it is a combination of the liner being bent in and the blade being crinked a little too far toward the liner that is causing this issue.

 

[lithicus]

Oh, and I agree about not trying to bend the liner back into place. It seemed the simplest solution at first, less likely to introduce blade play etc etc. But, I do worry it would result in cracked bone no matter how I go about it. Just seems like a bad idea. Most information I've found about fixing bent liners involves disassembling the knife, which I'm not apt to do.