Blade wobble "cure" (Wanted)

coyote711

coyote711

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Sep 19, 2009
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Squeezing the bolsters in a vise, whomping the bolsters with a rubber mallet, even super glue (a la Jani) ..... all possible cures for blade wobble. I've tried the first two methods, with success on some knives, and no effect on others. Regardless, it usually leaves the pin visible in the bolsters afterwards. I would assume at one stage in the manufacturing process the pins are also visible, and then they are polished, or buffed, or something is done to make them "invisible". Anything a layman can do to "hide" the pins again?

I realize I'm getting in over my head here, but it would seem that the only thing accomplished is to have temporarily squeezed the bolsters a little tighter, and without somehow also compressing the pin, or at least making the pin & bolster "one" again ..... well, all ya have is a temporary fix which comes undone when you put some lateral pressure on the blade -- so you're right back where you started - blade wobble - plus now you can see the pin in the bolster. :rolleyes:

Perhaps some knifemakers, or others more knowledgeable than I, can explain the folly or wisdom of these homemade fixes. ;)

P.S. I'm hoping Gus & Elliott will be able to leave this in the Trad. sub-forum, but if it has to be moved, it has to be moved. ;)
 
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You probably need to sand it out and use then dremel with cotton end in green polising combound to polish the mark. Usually getting from 1K to 2K grit sandpaper and then polish it could do the trick.
 
Keith, it's better if it's moved for a couple of reasons...

First, a permanent link with the Traditional Forum is left behind so folks can find it easily...

Second, this way all members of the forums, even those who don't frequent our little corner of the universe, will be able to find it in the area set up to house such threads.
 
Get a buffer (or grinder if on an economy like me). The 1700rpm is much easier to use, but if you are careful 3600 is fine. Get a fine cratex wheel for one side and a soft buffing wheel for the other side. Lowes has a very nice yellow buffing wheel (get two and put them on together for a thicker surface). You will need some appropriate compound for this wheel. Get a small ball peen hammer and grind down the small side to a V shape (a little flat on the end instead of sharp). Take an old butter knife and cut about half of the blade off, then sharpen the rest of the blade (not sharp, just enough to be a pry).

With these simple tools you can solve many of the cosmetic problems that come your way with knives. Less than $100 can save a lot of time / headaches.

Put the bolster on a piece of wood (bolster only, no slab touching on the backside); and tap the top with the big side of the hammer. Test to see if the fit suits you; when it does spread the protruding pin with the V side of the hammer. Clean up the bolster with the cratex wheel, then get a mirror finish with the buffing wheel.

If you get it too tight, or if you have one that is not snapping like you want, you need to loosen the joint up. Open the blade that is tight, place the butter knife inside the liner wherein the blade closing on it will put outward pressure on the joint. Essentially pinching the butter knife between the closing blade tang (done use the blade itself or you will mar it) and liner. This butter knife can also be used to shear pins when taking a knife apart.

One more good tool is a wire cutter that has the solid side ground to flat to allow more of a flush cut. You can buy flush cutters but they are usually a lighter weight than a good wire cutter.

Also, a 1" belt sander is very useful and can take care of those blades sitting too high in about 5 seconds. Once you have a belt that is about bare of grit, it can be used to straighten up those factory edges that are coming so poor these days. Once it has no grit on it, use it as a high speed strop.

Using these tools to correct small issues will give you much more appreciation for the complexities.
 
Mike, thanks so much for sharing your knowledge! :thumbup: I have some questions related to the following:
knifeswapper said:
Get a small ball peen hammer and grind down the small side to a V shape (a little flat on the end instead of sharp).

..... when it does spread the protruding pin with the V side of the hammer.
Click to expand...

Would a very small chisel or punch (ground a little flat) work in place of grinding down the ball on ball peen hammer?
Are we basically just trying to mushroom the pin so it's attached to, or grips the bolster better?
And would I need to do both sides if the pin, or only the side protruding?

Thanks again, Mike!

(Totally understand the move, Elliott). ;)
 
The V on the hammer is to enhance the flare. If you just pound the bolsters / liners together without locking them by peening; it is only a temporary fix. Also the V working around the edges will actually spread the surface as opposed to just smashing the whole pin. Don't know if that makes sense.

Most factories do this operation with a shim in place to prevent getting it too tight for smooth movement. That often times leads to the movement that is so dreaded. You try getting a couple to suit you and you may never be bothered by a little movement again ;>

Only the side protruding is fine. If you try the brute force method you will get the other side protruding anyway.

Many makers use a taper bit on the holes before peening; this gives you more grab from top to bottom instead of just on the surface. This keeps you from causing as many cracks on the slabs as well.
 
Mike, everything you said in your last post makes sense, and clarifies what is trying to be accomplished here.

I just tried the fix with a small ball peen hammer and block of wood on a Queen, a Case, and a Buck that all had blade wobble - the wobble is gone on all three now and they still have a satisfactory amount of snap on all the blades! I probably didn't use quite enough finesse in peening the pins and consequently had a few dimples in the bolsters, but some fine grit sandpaper and steel wool removed them to my satisfaction for now. I'll look into a cratex wheel and a buffing wheel as per your suggestion for the final finish.

Thanks once again, Mike! :thumbup:
 
so, couple of slippies had a little side play

took:
knife :)
hammer
2 pieces of wood

made a sandwich of the wood and the knife (knife laid on the wood and a piece of wood on the bolster only)
hammered on the piece of wood that is on the bolster twice with not much force
wobble away! now I have to sand down the pin that rised from the bolster, any way to push it in? instead of sanding?

haven't understood the part with the V hammer, any pics? thanks!

it worked for me

maxx
 
A "V" (cross pein) hammer is not really necessary.
The pin heads must be flared, or they can't hold the bolsters tight. After flaring, they can be sanded flush.
 
With a small hammer. Use the flat head. Tap gently on an anvil.
 
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