Stones for sharpening, etc

[Hirsh]

I have a few large knives and axes that make more sense to sharpen by taking the stone to them, rather than the other way around. I have many stones and such in my yard that I was hoping to use to do this, but have no idea where to begin. Does anyone have any insight as to which types of stones are well suited for sharpening like this? Im not looking to put a new edge on these things, the edge bevels are already established and suitable for my needs. Im really just looking to hone the edge and create a nice sharp point.

Im assuming that a flat, smooth, and dense stone would be good...but thats just all in my head, hopefully someone here has done this before and can really tell me what to look for. Im also aware the roughness of the rock will probably play a big part in how abrasive it will be. I do have some nice water-stones and oil-stones that I use to sharpen woodworking tools, but they are too small for this, and honestly I don't want to drive to the store and spend money on something I know I can just find 10 feet from my door.

Thanks for your help.

[Rick]

You can't just pick up a stone and use it to sharpen a knife or an axe. The impurities in the stone along with the random density throughout the stone will not give you a uniform edge. That's why commercial stones were developed. You need a stone who's surface is uniform in grain and density and maintains that structure throughout the depth of the stone if you intend to continue using it.

[kyratshooter]

We call them "sharpening stones", and some of them are made from natural materials, but there are very few rocks one can pick up from the yard and use to sharpen a tool.

My sugestion to someone with as little experience as you seem to have, is to go to Wallmart and buy a sharpener off the rack.

http://www.walmart.com/ip/Mustad-Del...pener/16563481

A device like this will retain, repair and sharpen the edge of most tools. They are simple to use and do a fair job.

[Wildthang]

Kray, before I would just use any old rock, I would use a cinder block. It will give you a rough hone. I needed to sharpen a hatchet one time, and used a cinder block. It was not a fine polished finish, but it got the edge back. I seriously doubt I would use it on a good knife unless it was a have to case, but for a hoe or hatchet, it works pretty good for a very course sharpening.

[kyratshooter]

Just like anything else, if you have the basics of sharpening down you can make many questionable things work, sort of. Thing is you have to know what you are doing and exactly what to look for.

When I was a kid I had a section of the cement patio polished smooth and it did wonderful work on my Sabre brand Barlow knife. My Mom used to hand me her kitchen knives out the back door and demand I put good edges on them. Fact is, she has always shoved knives at me to sharpen every time I visit the house!

I once "visited" some folks in a tropical region who had a nice flat rock down by the river and they would send their kids down there to sharpen the machettes.

Then there were the people I worked with that made "shanks" by grinding away on the cement floor with anything they could find.

I still like Crash's system better. A Grizzly Grinder and buffing polish!

For a hatchet, axe, machette or garden impliment I would just as soon have a good file handy. I am picky about most of my knives though.

[Hirsh]

We call them "sharpening stones", and some of them are made from natural materials, but there are very few rocks one can pick up from the yard and use to sharpen a tool.

My sugestion to someone with as little experience as you seem to have, is to go to Wallmart and buy a sharpener off the rack.

I do have a good bit of experience with conventional sharpening methods and using the standard commercial stones. As a woodworker I am always challenged to keep my handplanes, chisels, drill bits, etc. sharp in order for them to work. I also grew up working in the woods with my father as a "lumberjack," so I also have basic knowledge on how to use hand-rub stones on axes and what-not. Im not really a big fan of those plastic-handled sharpeners because I dont get to determine the bevel angle that I put on my blade (or axe or whatever). Id rather be able to control that manually, first by grinding my bevel, and then honing a micro-bevel or just retaining the same angle. And then sometimes the angle of those grinding edges inside the sharpener dosent match what the axe or knife already has on it, so if the sharpener is too acute you dont actually sharpen the edge at all, just the shoulder of the bevel.

What i really dont have experience with is the sharpening stones that can be found naturally. I was hoping to find something more "primitive" and gain knowledge so that if i were out on the trail and wanted to sharpen something, I would know what to look for...and also what not to look for. Now that i see they are somewhat rare and harder to find (stone with uniform density and grain as Rick said) Ill probably just resort to using a store-bought hand stone here at home. Which is no biggie at all. I have heard of the "Arkansas Novaculite" stones. This seems to be a very popular natural stone, but I have no experience with them.

So just for the sake of trying to learn more...if I were to look for these naturally occurring stones what exactly would I look for in a "natural sharpening stone?" Is something like slate a good choice? it would be relatively easy to get a flat surface...but I would not be sure how the grain and density of the stone is. To me it seems soft...but maybe that is a good thing? I have a set of old cement steps out back, so maybe I will give that a try tomorrow just for fun...along with some other random river rocks laying around to see of they even work at all.

[randyt]

For a natural stone consider a piece of natural sandstone with water as a lubricant. You'll have to try out a few until you find one that works to your satisfaction. The good thing is they're priced right. I like a puck or file for sharpening an ax but options are always good.

A stone can be scrubbed against a harder stone to help true it up.

[Rick]

I was going to mention that as well but only as a last resort type of thing. Sandstone is pretty plentiful just try to find a decent stone that appears to be fairly uniform in grain size. The metal shavings you cut off the knife or axe are called swarf. Using water helps as a lubricant but it's real benefit is carrying the swarf away so you don't continue to roll the blade over it. You want the metal to make contact with the stone.

About the only natural stone that is truly good for sharpening is Novaculite but it's not something your apt to find in your yard. Here's a wikipoo on it.

http://en.wikipedia.org/wiki/Novaculite

[crashdive123]

If you are going to look for a "feral" stone for sharpening in the part of Florida where I live, you will be looking for quite some time. Lots of sand and sea shells, but not stones.

[randyt]

I hear tell that fossilized coral and petrified wood makes a passable whet stone. TBH though I don't have experience with those rocks..

[Hirsh]

I was about to ask about fossilized coral. Now go figure that there are two chunks of this in my yard. Ive only been in this house 10 months or so...and it seems like the previous owner had them in/around a flower bed out back. Ill head out back right now and try it out and report what happens. Maybe a fresh slice in my finger is all.

Seeing as it is quite rough...and ideas on how to true the surface? I dont have any commercial truing stones...and ill start by just trying a harder stone or the concrete steps out back and see what happens.

[crashdive123]

Fossilized coral, before it is baked is relatively soft. As far as the "rough" areas go, you want what is below that. Breaking or splitting fossilized coral should reveal a solid surface. You should be able to knap a flat spall from it if it doesn't crumble. I haven't tried to sharpen with one, so can't tell you how it will work - but will say that you can probably produce flakes that are sharper than your knife.