All About Pocket Knives

Ok- so I have this Challenge Teardrop Jack. Nice enough knife, except that the main blade has some wobble at full open position. The secondary blade is tight. Perfect, actually.

What does this likely mean? Do I have a broken pin, or is this something that might be fixed with a light peen? If the peening might work, would I peen the mark side or the back side, or does it really matter?

As seen in the photo, the pin on the mark side is actually raised above the bolster- microscopically so, but you can feel it. Seems probable this knife has been taken apart and put back together at one time.

I'm pretty sure I could do the peening without causing any undue heartache, if that would do the trick. Anything else and I'll have to wait until I get to to speed with repair techniques. I've just gotten a few old beaters to take apart and re-assemble, just to get learning.

Ray

what has happened, in my less than expert opinion, is something like this. Think of the pivot pin on that side as a T shape, with the vertical part of the T the part than runs through the knife. the cross of the T is the Peened area. this area holds the blades tight. over time, this T ends up looking more like a Y, which allows some side to side movement in the blades. this may be more evident when the blade is open, if the tang is slightly beveled. putting in a very thin shim, or slackener, then peening it back to our hypothetical T would likely tighten up your action.

I'd get some more opinions before you go and take mine though

two more cents...

I think that if the small blade is tight, what might have happened is wear to either the pin or the pivot hole in the big blade....imagine that most big blades get used 2x or 3x to every time you use the small blade. This means that much more wear. If the pivot hole in the blade has enlarged a bit (or the pivot pin has eroded), this can translate into side to side movement when open.

Or, during manufacture, the large blade had a slightly larger hole drilled...resulting in a wobble right from the start.

Or, the large blade has been "pried with", which could raise the edge of the peened pin up a bit. I've done this when I haven't peened very well, and then ground off too much of the bolster and pin during final polish and shaping. (ie the resulting peen is too thin to resist the force from prying) Look at the bolster from the side and see if the pin looks like a cup (like a contact lense sitting on the table). If so, you might be able to rectify with some peening and polishing.

Or, a combination of the above. Particularly if the small blade is just fine.

Is this happening? well, I can't tell you without taking the knife apart. You could always do a very light, repeat very light, re-peen of the pivot pin. (either with or without a slackner) and see what happens. Either the blade will get tighter, or it won't....

If it was me, and I didn't care about the result, but was more interested in experimentation, then I would peen a bit and see what happens.

Orvet?
Muskratman?
Rigwelder?
anybody else?

D

Thanks for the replies, Adam and Diligence.

This talk of T's and Y's makes me realize that I might not have the first clue, really, as to what the insides of this part of the knife look like and how it fits together. I mean, I have a gist, but maybe the pin functions differently than i suppose? Anybody have a photo of this end of a knife taken apart, pin(s) and all?

Ray

I was just trying to illustrate without the aid of any kind of graphics It's tough while I'm at work sneaking AAPK peeks on the laptop

When I get home, I'll diagram something up for you real quick that kinda explains how that stuff is laid out, unless someone beats me to it. D and I are both talking about the same thing for a bit, but he does bring up a good point with pivot hole being a bit bigger, or the pin being worn. that can definitely happen

*edit* home now, this should maybe help illustrate what we were talking about

Hey Adam- thanks for knocking out the illustration. Very cool of you, and helpful. As I said, I've got a few old knives here I'm going to crack open to have a look at & practice on before I start in on the better knives.

Thanks again

Ray

I think Jaye has pretty well covered all of the likely scenarios that have caused your pins to loosen.
I think the most likely possibility is that someone has pried with the blade. That seems to me to be the most common cause of side play in a blade. I doubt your knife has been taken apart, but it is hard to tell, especially from the picture.

Excellent illustration Adam! Sure beats a hand-drawn picture (especially my drawing).

If you want to learn to repair knives I recommend going to a flea market and buying a bunch of medium quality knives and working on them. Often you can find decent quality knives at a very good price in a flea market. Most of us got our start working on knives in precisely this manner. If you buy the really cheap knives and end up getting some with shell handles, it will be much harder for you to repair them. The construction of a shell handled knife does not lend itself to easy repair. You can tell of the knife is shell handled by looking at the end and seeing a little tab of metal bent down to hold the shell handle on. The brand names that you will usually find with shell handles are; Imperial, Hammer Brand (the later ones made by Imperial after the mid-1930s), Colonial, and Rogers of Sheffield. These are not the only makers of shell handled knives but they are the most common, and the ones that come to my mind at this moment. Imperial and Colonial do make knives that are not shell handled, and they would be fine to work on. Just look for the little tab at each end of the knife.

Some people hone their skills at knife repair by buying some inexpensive Chinese made knives such as; Rough Rider, Steel Warrior or some other brand. I guess that's fine if you don't mind supporting the Chinese economy. Personally I prefer working on the old American-made knives.

When you start working on knives be sure to take a before picture and an after picture and bring them into the forum and show off your handiwork. It allows you to be proud of the work you've done and sometimes someone can make a suggestion that will help you in future projects.

One thing you need to be aware of: customizing and repairing knives is far more addicting than just collecting them.

Go for it, enjoy it and let us see the results of your work.
Dale

Thanks for the advice Dale, regarding shell handles & etc.

It is sort of odd how addicting even the idea of knife repair has become- but then I've always been a pretty hands-on guy and mechanically inclined, so I guess I shouldn't be very surprised that I'm being sucked into it.

And, on another note: TGIF

Ray

My only reason to use Rough Riders for "NEW" modifications, is that I can throw them out in the trash and I don't feel bad at all. I bought a bunch at $3-$6 each 3 years ago - seems that they cost twice that now - or more. I did buy them at a dealers cost including some e-toes. They are for experimental "stuff" as well as having some 1095 and 1084 carbon steel scrap pieces for just filework. Nice soft annealed steel - you can work it pretty fast.

I'd feel bad if I screwed up an old but cheap American knife. If I had not gotten the RR's at a low price, I probably would not have bought them as throw away's.

semloh, you do know about the swinden key style knifes don't you? I'm no knife maker or fixer but I have saw both styles taken apart before. I think there was only a handful of companies that built their knifes using the swinden key style. One of the other members with more knowledge than me can explain how the swinden key knifes are made and work. Wish I had the talent to make/repair knifes like these guys on here do. Collecting knifes is a big enough habit for me, making/repairing knifes is a very strong bug to be bitten by they say.