How tough is cardboard?

J

Jack Goertz

Joined
Feb 28, 1999
Messages
91
My Wegner jr. is a couple of months old and I cut up LOTS of cardboard boxes. I don't mean just a flatting them out - but rather whacking them up into strips. They are heavy shipping boxes and after doing a couple of them the kife needs resharpening to keep it slicing really well. The blade is ATS-34, which is pretty good stuff, and the hardness is Rc 59-61. I've noticed fine scratches on the blade angling back with the direction of the cuts. The scratches could only be put there by the cardboard. They're not deep, in fact the blade must be held up to the light just right to see them, however, they are unmistakable. How abrassive is that stuff, and has anyone else had this happen? I'm not concerned about the esthetics - the knife was purchased to be used, but I'm surprised that carboard could do that.

Jack
 
It's not so much the paper fibers in the cardboard but the various and sundry other materials which find their way into the cardboard. I've even used cardboard to strop some knives before and it worked well (if that gives you an idea of how abrasive it is). Paper products are rarely just wood pulp. A lot of papers contain kaolin which is a type of clay. That is why glossy magazines are so heavy. I hope this helps a little, i'm sure some of our more scientific forumites can explain better than I.
 
Jack, cardboard seems to be one of those things that can dull a knife quickly. I'm sure Paul is right about the 'extra' ingredients, in cardboard, being the main abrasives. I find a coarsely sharpened blade holds up better against cardboard, as opposed to a knife stropped to a razor edge. If cardboard is what you cut the most, try using a coarser stone and leave out any final edge finishing. Different materials tend to require different sharpening techniques for the best results. Perhaps someone on the forum, with more "cardboard" experience can give you some better info.

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Bill
"Walk softly and carry a big folder... and a small folder... and a SAK... and a multi-tool..."
 
That's why EVERY ONE should own a SPYDERCO SHARPMAKER!

Not only is it fairly easy to use, it's FUN!

Had to put that plug here, what a better place for it
wink.gif


Mark
 
The cardboard that we use in our edge tester is custom made, but it has a predetermined amount of abrasive (quartz) built into the card. This is because cardboard in general has the "other stuff" mentioned by Bill & Paul.

thanx, Mark.

sal
 
When you say "coarse sharpening for cutting cardboard," are we talking about the coarseness of the medium stones of the Sharpmaker? Or coarser than that?


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Work hard, play hard, live long.
Outlaw_Dogboy

6/3/99 3:45pm- Thanks phone_archer


[This message has been edited by Outlaw_Dogboy (edited 03 June 1999).]
 
Outlaw, I've had the best luck using a Norton fine india stone. It's not very coarse (600 grit - I think), but I don't finish the edge on a strop. There is a good FAQ on sharpening, but what I do is the following. Making sure to hold the blade at a constant angle, I sweep each side alternately until I get a burr. I then raise the angle a few degrees and make a couple of light swipes on both sides. This removes the burr and gives a 'micro-bevel'. The knife will now be sharp - it may not be a 'hair-popping' razor edge; but it seems to hold up well on things like cardboard. If I want a razor edge - I skip the last step and strop it on leather charged with honing compound.

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Bill
"Walk softly and carry a big folder... and a small folder... and a SAK... and a multi-tool..."
 
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