Sharpening a RAT 7

[dibble]

Howdy folks - hope someone can help!
I've just recieved my Ontario RAT 7 in 1095 steel, and unfortunately it came as sharp as a butterknife! I've got a Spyderco Sharpmaker - advice from Bladeforums.com was to use a 30 degree angle to begin with to remove the shoulders, then sharpen with a 40 degree angle as usual.
I've been at it for a few days now, and it's got a little sharper but not as sharp as it could be.
Does anyone know of any places (preferably in the Notrh West) where I can take it to get an initial edge on it so I can maintain it in the future with my Sharpmaker?
Thanks in advance!

 

[Hoodoo]

The Sharpmaker is really not suited for reprofiling knife edges, especially on a knife as large as the RAT-7. Not sure what to tell you about getting the edge in shape. There is literally a TON of info on this site about sharpening. You might want to do some exploring.

Sharpening is hard work, especially if you are reprofiling the edge. But a good edge is worth the work. If you are trying to remove significant metal, you need more than the Sharpmaker. Sandpaper, stones or diamond sharpeners will help shape the edge a lot more quickly than ceramic stones.

 

[Yorkshire Boy]

Well, I'm a complete novice.
I screwed up my Falkniven F1 trying to do what the experts do.
I made it fairly blunt and put big blocks of scratches all over it!
Very upset

I got a wetstone and slowly worked on it.
Then I gave it a few swipes on a leather belt.
Hey presto, a bald leg!!!

Slowly but surely it will happen.

My knife is still marked from sandpaper and wet and dry.
I'm sure it won't effect the blade, it just doesn't look cool anymore.

Keep the faith in your knife (very important if you ask me).

Best of luck,
Yorkshire Boy.

 

[Ramapo]

There is literally a TON of info on this site about sharpening. You might want to do some exploring.

That's part of the problem!

I just got that TAK-1 in D2 a little bit ago, and I'm in the same boat: I know it's a decent knife, but boy, it came with an edge that was less than impressive. So, I've done some digging on here and spoke to a knife maker that I have a blade on order with and I've taken a few preliminary steps.

I've ordered a soft Arkansas sharpening stone and a book on sharpening...and sifted through a lot of the info on this site, but...

...I'm pretty new to this and not certain that I'm taking the steps that best resolve my situation. So here are a couple specific questions:

1. How do I identify what type of edge I have now. I know the factory edge is not a scandi, but how do I tell if it's flat or convex etc.? If I'm going to be messing around trying to hone the edge, I need to know what I've got to work with.

2. I assume that I can get a great edge using the Arkansas stone and a strop, is that correct?

3. How do I ensure that the angle I'm sharpening the bevel on is correct? Can I do this freehand being the noob that I am, or do I need some sort of a jig to maintain a consistent ange?

4. Is there anything I'm missing?

Any advice specific to sharpening up a factory edge on a RAT blade would be very greatly appreciated!

 

[Hoodoo]

That's part of the problem!

I just got that TAK-1 in D2 a little bit ago, and I'm in the same boat: I know it's a decent knife, but boy, it came with an edge that was less than impressive. So, I've done some digging on here and spoke to a knife maker that I have a blade on order with and I've taken a few preliminary steps.

I've ordered a soft Arkansas sharpening stone and a book on sharpening...and sifted through a lot of the info on this site, but...

...I'm pretty new to this and not certain that I'm taking the steps that best resolve my situation. So here are a couple specific questions:

1. How do I identify what type of edge I have now. I know the factory edge is not a scandi, but how do I tell if it's flat or convex etc.? If I'm going to be messing around trying to hone the edge, I need to know what I've got to work with.

2. I assume that I can get a great edge using the Arkansas stone and a strop, is that correct?

3. How do I ensure that the angle I'm sharpening the bevel on is correct? Can I do this freehand being the noob that I am, or do I need some sort of a jig to maintain a consistent ange?

4. Is there anything I'm missing?

Any advice specific to sharpening up a factory edge on a RAT blade would be very greatly appreciated!

Scandi edges are obvious. Large, flat grinds that go up the blade a ways. Sometimes half way up. Get a 10X hand lens for looking closely at the edge if it has a small bevel. As far as I know, the TAK comes with a secondary bevel that is not convex.

The Arkansas stone is less than useless for profiling an edge. Too fine. That is a stone for final steps. If the edge really needs some work, you need something more coarse.

There is this myth that the angle has to be precise. Not really. But what has to occur is that the sharpening on both sides of the bevel has to go all the way down to the edge. Lots of people sharpen and sharpen and sharpen and don't realize they are working on the upper part of the bevel and not the lower part. You know you are on the lower part when you have formed a wire edge on the opposite side of the bevel. Sharpen one side until you get this wire edge. Then turn over and do the other side. Use a hand lens to check your work. Use a black felt tip marker to mark the edge and then make a stroke or two and check it. This will tell you where you are sharpening on the bevel. You may want to spend some time on the upper part of the bevel, though, if it is too thick for you purposes.

Practice, practice, practice.

 

[eros69]

You could buy diamond stones for your sharpmaker, that would do the trick but they are pricey (£55 ish). If you dont mind paying postage there and back I will sharpen it for you gratus. Drop me a Pm if this helps Dibble. All the best Eric. Oh and dont under any circumstances let any one persuade you to use a grinder on it. The heat can ruin the temper.

P.S This is my first post on here so am not known. My usual haunt is on British Blades. You can check out my rep on that if you are wary of posting your knife to a stranger.

 

[Ramapo]

...TAK comes with a secondary bevel that is not convex.

Okay, help me out with this one! I'm not sure I'm understanding the distinction between a (primary) bevel and a secondary bevel. I think it's just difficult to describe in writing. Do you know of any links to a good diagram that can help me out here?

The Arkansas stone is less than useless for profiling an edge. Too fine. That is a stone for final steps. If the edge really needs some work, you need something more coarse.

Damn! How about a coarser Arkansas stone? Or is there something else you'd suggest?

There is this myth that the angle has to be precise. Not really.

At last, some good news!

Lots of people sharpen and sharpen and sharpen and don't realize they are working on the upper part of the bevel and not the lower part.

Again with the upper & lower bevel. I bet the reason this happens is because they're like me and can't distinguish between the two properly!

You know you are on the lower part when you have formed a wire edge on the opposite side of the bevel. Sharpen one side until you get this wire edge. Then turn over and do the other side.

I'm not sure what you mean by wire edge here, Hoodoo. Do you mean, a sort of slight bur that wraps around the other side of the blade?

You may want to spend some time on the upper part of the bevel, though, if it is too thick for you purposes.

I have a lot to learn apparently!

Practice, practice, practice.

You know it. This seems like a good skill to have. And I need to learn before I get my Skifa!

 

[Ramapo]

By the way dibble, I'm not trying to hijack your thread! I hope you find my questions helpful. It seems that advice that's good for you will be good for me (and vice versa) in this situation.

 

[Longstrider]

Hi guys, As those who know me are already aware, I swear by diamond hones for sharpening just about anything. Whether it's a blade that simply needs a little more attention than a few wipes on the strop, or a full re-profile job. Obviously, you need a range of grit sizes to be able to cover all eventualities, but they work for me so I stick with them.
A coarse, or even better if you can get one, Extra Coarse, dimaond hone should manage to re-profile a knife in half an hour or so. After that it's just a case of working down through the grit sizes to Extra Fine, then strop for a polished "shaving sharp" edge.

The difference between the primary and secondary bevels on a knife are best described if you can imagine a blade with some sort of coating on it. The blade will normally have a section near the spine that has parallel, flat sides. This is the un-ground section of the blade. The primary bevel is the "sloped" bit that goes from the flat parallel towards the edge. On a coated blade this will have the coating on it just the same as the un-ground portion. A secondary bevel is the (normally) very fine bit right at the edge where the metal is shiny, because this is the bit you sharpen. Take a look at a picture of something like a Cold Steel TrailMaster with the black coating on it and you'll see the different portions of the blade clearly defined.
A "Scandi" ground knife has only a single bevel (no secondary) and should be sharpened by removing steel from the whole flat surface of the grind. A convex grind should also be sharpened without a secondary bevel, but this time the steel has to be removed from the entirety of the convex curved section of the blade (the convex grind). A knife with a hollow grind (like a Buck 110) has a secondary bevel, as do many knives with flat grinds or "sabre" grinds.
When sharpening a knife with a secondary bevel I usually work free-hand, and as I like to have the secondary bevel on my knives to be slightly convexed I make them so with my diamond hones before stropping to a polished edge.

You're right about the "wire edge" It's the little burr that can form at the very edge of the blade which will flop from side to side as you try to remove it. I personally never do as some folks say to do and rely on the strop to remove this "wire" as a stroke or two into the edge with my Extra Fine hone removes it for me prior to stropping.

If either of you are still really struggling with your knives, like eros69, I'd be willing to do them for you for the price of postage (and perhaps a small something for my poor dry throat if we ever get to meet up at a Moot )

 

[Hoodoo]

Okay, help me out with this one! I'm not sure I'm understanding the distinction between a (primary) bevel and a secondary bevel. I think it's just difficult to describe in writing. Do you know of any links to a good diagram that can help me out here?

Damn! How about a coarser Arkansas stone? Or is there something else you'd suggest?

At last, some good news!

Again with the upper & lower bevel. I bet the reason this happens is because they're like me and can't distinguish between the two properly!

I'm not sure what you mean by wire edge here, Hoodoo. Do you mean, a sort of slight bur that wraps around the other side of the blade?

I have a lot to learn apparently!

You know it. This seems like a good skill to have. And I need to learn before I get my Skifa!

Oooops! Sor-ry for the confusion. When I said upper and lower, I was talking about the same bevel, just a different place on the bevel.

A secondary bevel is the tiny bevel right at the edge. Some knives have them, some don't. The Skifa you will be getting does not have a secondary bevel. It just has one large bevel called a scandi bevel, and you sharpen this bevel by laying the entire bevel flat on a stone. Your arkansas stone will work great for this for awhile.

So, the secondary bevel is the bevel right at the edge. When you sharpen this bevel, and you are holding the knife lower than the actual angle of the bevel, you will be working on the "upper" part of the bevel. This is fine if you want to thin the bevel a bit. eventually though, you want to make sure you sharpen the entire bevel. in other words, you need to make sure that you are not just grinding on the "upper" part of the bevel. When you have created a burr or wire edge on the other side--one you can feel with your fingers--you know you have sharpened all the way to the edge of the blade. You also want to make sure the burr extends the entire length of the blade. Once you have that, sharpen the other side the same way until you have the wire edge on the other side. Continue this process with finer and finer stones and then strop to remove the final burr. Or as was mentioned, you can remove the burr by raising the blade slightly and making a few passes on a very fine stone.

I would read over the material here on sharpening first. There's a lot here. I'm sure British Blades has an FAQ as well. Do a Google search on Sharpening FAQ and you will find Joe Talmadge's FAQ on sharpening that explains things in much greater detail, along with some finer points.

A good method of sharpening is to use wet/dry sandpaper. This is my preferred method. It's cheap and effective. Just attach a piece to a board. When it gets worn down, replace with a fresh piece. There's lots of info here on that method as well. I think it's part of the sharpening sticky.

 

[weaver]

An easy way to learn sharpening is to use a black magic marker to color the edge of the blade about 5mm wide and the full length of the blade. Now when you hone the blade you get immediate feed back as to what is happening.

If the black is disappearing away from the edge you need to raise the back of the knife.

If the black is disappearing only at the very edge then you need to lower the back of the knife.

You should be removing metal on a scandi for the full width of the grind.

And on any other knife the 1.5 - 3 mm at the very edge unless you are reprofiling then further back from the edge.

Recolor the edge occasionally to see how well you are progressing.

 

[dibble]

Wow! Cheers for all the advice folks!
The Sharpmaker did an excellent job on my Mora, but is definately struggling with the RAT!
Eros (or Eric) - thanks for the offer - I'll PM you if thats ok

 

[eros69]

Thats cool Dibble. Should have your blade honed and back within a week at most. PM me and I will send you the postal address. Longstrider is right. If you have diamond hones it makes life a lot easier. I favour DMT hones for free hand sharpening if you are looking to invest in a set. All the best Eric

 

[Ramapo]

Eric, which DMT hones do you have? I was just checking out the DMT whetstones online, but they're pretty pricey. I was wondering which ones ou like.

Can you achieve the same degree of sharpness with Arkansas stones?

 

[weaver]

DMT seems expensive but consider it near a lifetime investment. My first one is over 10 year old and still works like new. I had a few other brands that wore out in a couple years.

If you get an extra coarse, fine and extra fine you will easily put a razor edge on every knife, chisel, ax and plane blade you own many times over. Far out performing any Arkansas stone.

I can shave with the finish straight off the extra fine stone. I usually strop to make cutting easier and the edge last longer but in a hurry it is sufficient.

I have the largest machinist plate, a couple of pocket stones and a rat tail for serrated knives.

 

[Ramapo]

Weaver, when you say that they out perform an Arkansas stone, do you mean that you get a good edge faster, or that the finished edge is better with DMT irrespective of the amount of time that you spend sharpening?

The bad thing about the interenet is that too many options can drive you nuts. I don't want to waste money on sharpening equipment that can't do the job, but I really do just want some sort of stone to start sharpening and learning with. I could spend all day researching whetstones online, but never get to the hands on learning curve...

 

[Ramapo]

By the way, Hoodoo, I found Joe Talmadge's FAQ. it has a lot of good info. Thanks for the heads up.

Also, do any of you guys know if all this info applies to a hollow grind like the one on the AG Russell Featherlite pocketknife?

 

[C_Claycomb]

Hollow grind usually just applies to the main grind, not the cutting edge. Chris Reeve's Sebenza has a hollow grind, but the cutting edge is done with a little convex "apple seed" shape.

I too like the DMT hones. I have water stones for the bench at home, and they are hard to beat for planes and such, but for knives, the DMT folding hones are great. For re-profiling I have had good luck with a 220grit great brick of water stone, which was cheaper than the DMT, but dishes out over time. Messy, but fast.

Arkansas stones are pretty slow. The one I have will give a nice polished edge eventually, but no where near as fast as a water stone, or diamond. The diamond works well on on everything, water stones take longer on high alloy steels. It is really a time thing. I use waterstones for sharpening s30V and D2, but I know it would be a little faster with diamond, but I haven't seen a real problem. With the Arkansas stones I have been there a long, long time, and not made a lot of progress when I need to re-profile.

 

[eros69]

Hi Rampao. Apologies for taking so long to get back to you. In answer to your question I have the ones that open like a butterfly knife (I think they call them diafold stones). They are double sided so have a different grit on either side. I have an extra course/course, and also a fine/extra fine. I also have a full set of their tiny pocket key ring sharpeners from extra course down to extra fine. They fold out a bit like a flip phone does. Thay are great for carrying about. The DMT stones are more expensive, but they should last a long long long time. I have had mine for years and there is no sign of wear yet. They also dont hollow out in the middle like stones can. Hope this helps

 

[weaver]

Weaver, when you say that they out perform an Arkansas stone, do you mean that you get a good edge faster, or that the finished edge is better with DMT irrespective of the amount of time that you spend sharpening?

I mean they are much faster and easier.