A friend of mine recently showed me a neat way to sharpen a knife. Use the edge of a vehicle's window glass. That's right...roll the window down, and run your knife back and forth on it just like you would on a whetstone. Use a little more pressure at first, ease off of the pressure when it starts getting sharp. I was amazed. My Spyderco (regular blade) with AUS-8 steel that is normally kinda hard to sharpen on a stone was razor sharp after about a dozen strokes.

great trick. do that all the time. I drive an HVAC service truck and when i can't find my razor knife I use my pocket knife to cut foam insulation tubing or cardboard.
Stop at a red light rool the window down and start touching up the edge.
just don't do this when a cop is stopped next to you.

I've run across this hint a number of times now, haven't tried it yet, but I see no reason why it shouldn't work fine- glass is for sure a lot harder than steel, and the edge probably is just "frosted" to a useful "grit" size. Obviously, if you do it a LOT, eventually you'll wear the edge of the glass.

You have to wonder, though- if it works well, why does no one market a sharpener made this way? A frosted glass rod could be set in something else to give it strength, and even alone, it's probably not a whole lot more fragile/brittle than some of the ceramic rods- and bound to be a lot cheaper.

Back when I used to work for the Falk corporation as a machinist, the tool room used to have blocks of compressed corrugated cardboard for fine tuning sharp blades. According to the individuals using those blocks, the effect was the same as stropping on a leather belt.

Anyone else hear or see anything like that elsewhere?

Bountyhunter

A dab of Carborundum paste on cardboard or even newspaper on a flat surface will do wonders.

Yep, I know someone who strops on the inside of a cornflake box.

Someone on knifeforums said that corrugated cardboard is what Mike Stewart, of Bark River Knife & Tool, uses to keep his personal knives sharp... but BRK&T knives are a bit unusual in being full-convex ground, like Fallkniven knives, and thus can be stropped flat against whatever... other folks, though, report no success with the method. I owned a couple of BRK&T knives briefly, but I didn't hang on to them long enough to need to sharpen them.

Cardboard carries lots of fine abrasive grit, it's routinely used to dull knives, or get some feel as to how long they'll hold an edge, so it should work for sharpening with different angles. Note that Trace Rinaldi feels that because of it's 45-degree micro-shearing (as opposed to steel's 90-degree), LiquidMetal (LM1) actually can actually get sharper from cutting cardboard, not duller!

just wonderin', never been real good with knife sharpening by hand, but when "stropping" a knife either on the window or cardboard. is it like you are trying to cut the item (ie, push the blade towards the edge or pull it away from the edge?)

thanks!

If you are doing this on the window, you will be pushing the knife as if you were trying to slice off a thin layer of the window.

I do that all the time...
I have a little piece of cardboard and have put Metalglo on one side, green compound on the other, and left the other two sides(it is folded in two) plain... I use the Metalglo first, then the green, then the plain...Works great...