To Burr Or Not To Burr?

[MetalManiac]

I'm trying to learn to use water stones. I've got 240, 1000 and 6000 stones. I've read that you grind each side until you get a burr on the course stone, do the same thing on the medium stone, then alternate side-to-side on the fine stone.

HOWEVER, I've also read that you should grind each side to get a burr on the course stone, then alternate sides on the medium and fine stones until the previous stone's scratches are gone.

What say y'all?

Also, if I'm just doing maintainence on a not particularly dull knife, should I skip the course and just grind to burr on the medium and alternate to polish on the fine?

Thanks!

[Fred]

Correct. The burr doesn't have much to do with cutting but it has a lot to do with communicating to you how the sharpening is going.

[Oded]

I second that.

I would not be using anything lower then 1000 unless the blade is really dull and need some serious grinding.
Properly maintained and un-chipped blades rarely if ever fall into the 'Dull' category.

I started experimenting passing the blade on the 6000 and 15000 before (or after) each use - I want to see how long I can run like that without going to my medium stone (2000) att all.
No conclusions yet - I am on a contract that takes me away from home for most of the time so I do not have much time for cooking these last few weeks.

[RETREVR]

If I am just touching-up a relatively sharp knife...I will sometimse just alternate sides on a fine stone. After doing this, I will run my fingers down the blade (use whatever method suits you to evaluate the edge). If I am satisfied, I call it quits. If I am not satisfied, I may drop down to a courser grit, raise the burr and go from there.

This is half comment,half question:
I was watching that video from shapton ( on their website) where the guy dmonstrates the stone flattener, and demos tool sharpening. He started on medium stone...lets say #1000. He raised the burr and then removed the burr on a fine stone...lets say #8000. He said "now the tool is sharp to #1000". He then moved up to the next finer grit( say #3000) and raised the burr and removed it on the fine stone.
Now, this method may be more appropriate on single bevel jap knives and may not be appropriate at all on double bevels. Does anybody use this method? Comments?
I usually raise the burr and wipe it off on the same grit then go to the next finer stone.

[Fred]

I leave the burr alone. By the time I get to 8000 grit there isn't much burr left.

[louisianacook]

Maybe had had already flattened/polished the back and didn't want to make any scratches? Not sure what he meant. Should work well on a yanagi, although I have seen the sharpeners on the Suisin videos use a coarser stone on the back side as well, not sure why...

Lee

[Fred]

Possibly to get the inside of the blade flat. I had to a lot of grinding to flatten the inside of my budget model Kikuichi Takohiki. Once it was done, it was a terrific performer but it did take some work. I used a 240 grit stone to flatten it.

[Oded]

Interesting...

This is the way I have learned to sharpen chisels:

Assume a Japanese chisel with primary bevel cut at 27 deg. (All Japanese chisels I know of are cut with only primary bevel, always at this angle). I also assume that the back of the chisel has already been honed flat and polished nicely to something like 2000 (I do that to all new chisels).

Step 1: Create a small bevel at 33 Deg with the 800 / 1000 stone until you raise the burr on the flat side. This is best achieved with the honing guide that ensures you can maintain the angle. This bevel should not be much more then 1 - 1.5mm. When it does, it is time to regrind the primary bevel.

Step2: Increase the honing angle to 35deg and hone a micro bevel (should hardly be seen) on the 8000 stone.

Step 3: Take the chisel off the honing guide and polish the back until you floated the burr. Sometime though, the burr will float when wiping the chisel with a towel but it is still a good idea to polish the back.

I think that when it come to knives, I tend to use the same stones UI used for the bevel on the back i.e. if I started with 2000 on the bevel I will hone the back starting with 2000. Thinking about it, I realise this is probably redundant and removes too much steel. I will try applying the above chisels method to single bevel knives and see what happens.

[Fred]

[ QUOTE ]
Interesting...
I also assume that the back of the chisel has already been honed flat and polished nicely to something like 2000 (I do that to all new chisels).


[/ QUOTE ]

This is something you wouldn't want to assume with the less expensive single bevel Japanese knives.

[MetalManiac]

So it seems like a decent rule of thumb (until I get better at all this) is to grind each side until I get a burr on whatever the coursest stone I'm using is, then alternate the rest of the way. So if I'm going coarse-medium-fine, I would grind to burr on the course, then alternate on the medium and fine. If I'm going medium-fine I'd grind to burr on the medium, then alternate on the fine.

Sorry, I'm bad at sharpening knives, but really good at not understanding things . /ubbthreads/images/graemlins/crazy.gif

[Fred]

The idea is to grind until you get a burr on one bevel. Then grind on the opposite bevel until you get a burr. When you've ground enough that a light swipe on each side produces a burr from one end of the blade to the other, Then you're ready for the next smaller grit. It's that simple.

[barbouni]

So I just got these cool Shapton stones and I'm feeling pretty good about my decision. However, I still am not quite sure if I am raising a burr or not. I have never done this before and am a little lost. Is there a way to check visually to see if you have raised the burr all along the edge? What magnification would be required? I tried the nail trick and feel a little difference between sides, but.... Any other tips on checking and how many strokes (how long time?) typically on 1k stone with German stainless.

Thanks

[Fred]

The difference you feel with your nail is the burr. There is no such thing as a number of strokes or anything of that nature. You're doing fine. Just keep working with the nail. Take care.

[VHo]

just received the 4 piece set of nortons (andy 777's advice) and ready to join the stone age! 220 / 1000 / 4000 / 8000 yee haa all them grits!

barbouni, I'm w/ you, pretty clueless, but I trust the bottle washer and andy. we'll learn together, sort of. /ubbthreads/images/graemlins/smile.gif

vho

[D & R Sharpening]

Hi barbouni,
Fred's right and gives good advice so keep at it.

I'd like to add one more thing that might help a little.

When you first begin sharpening it often helps to use a black magic marker on the edge. This will show you what part of the edge you are hitting and from that information you can adjust for corrections.

When the majic marker is completely removed down to the very extreme edge then it's safe to assume (one of the rare times in life you may do so) that a burr has been formed.

*Note - If neccessary, use magnification to make sure that all of the majic marker has been removed. Don't guess - make sure.

Flip the blade over and repeat.


--Dave M.--

[VHo]

with a single bevel knife, you're supposed to grind the beveled edge (the one w/ japanese writing) at 15 degrees. then grind the other side flat till the burr is easily moved side to side, then go to next stone?

vho

[barbouni]

Thankd for the tip D&R.

[D & R Sharpening]

VHo,
It doesn't matter what edge on what tool we're talking about as the same (magic marker) technique can be used universally well.

The biggest thing to remember when sharpening chisel ground knives (with hollow backs) is to first flatten the back side completely before moving on to the beveled side (face/outer side). This is a very important step that you will spend most of your time on, especially the first time you sharpen the knife.

After flattening the back side (hollow side) flip the knife over and sharpen the beveled side completely. When that's done, all the way to the very edge, flip the knife over and run the blade flat on a polishing stone to bend the burr back straight.

Then you flip the knife back to the beveled side - repeat, then back to the flat (hollow) side - repeat...and so on until no burr remains.

A chisel ground knife is no different than a chisel itself when it comes to sharpening. You must flatten the back first before going to beveled side.

--Dave M.--

[D & R Sharpening]

You're welcome!! /ubbthreads/images/graemlins/smile.gif

--Dave M.--

[D & R Sharpening]

Hi guys,
I've been thinking about what I just posted regarding sharpening chisel ground knives. I need to point something out and make a correction to my post.

Flattening the back side of a chisel first (or second) is something that's debated within woodworking circles. Both methods have advantages and disadvantages to them.

Most people believe it's best to do the bevel first followed by the flattening of the back. I've tried both and prefer to do the back flattening first and this comes from my experiences with several different types of tools that have chisel grinds to them. There are exceptions to my preferance and this is why I'm posting this "correction" now as I wish to reduce the confusion I nay be creating.

After some careful thought, I think that it would be best to advise to grind the bevel side first.

When going directly to the back side (flattening the back) first, there's several key variables that need to be considered. These variables are difficult, and uneccessary, to explain here.

I often forget that I'm talking from a different perspective than most have when it comes to sharpening.

Sorry for any confusion. /ubbthreads/images/graemlins/crazy.gif

--Dave M.--

[louisianacook]

Another important thing to remember when sharpening a yanagi is that it is hollow on the back for a reason. Don't grind the back side so much that you start to lose the concavity of the back. The two bevels on the spine and the edge should be pretty narrow. If the knife maker has done his job, there shouldn't be a need to "flatten the back" very much, if at all. Also make sure when you do this that your stone is dead flat.

[Fred]

Some single bevel knives aren't flat enough on the inside. I understand thay are concave. What I mean is that the perimeter of the blade on the inside needs to be flat. If it isn't then you need to do some grinding until it is.

At that point, I agree with dave. Once the inside is flattened do your grinding on the outside and it takes just a single stroke on the inside to finish the job. Take care.

[D & R Sharpening]

Yeah, you guys have it. That's what I was trying to say. /ubbthreads/images/graemlins/smile.gif

--Dave M.--

[yuzuha]

Right. I picked up a cheap deba at a local Japanese market (talking cheap < $25) and the back was concave but the blade was not really flat (wound up doing quite a bit of lapping on a diamond plate to get a flat perimeter around the edge of the concave back before I could properly sharpen it on stones)

[VHo]

thanks all for the input. /ubbthreads/images/graemlins/smile.gif

yuzuha, I'm curious what you use to, look at / evaluate, the blade. a magnifying glass? microscope?

too wiped out from work to do any grinding yet, but excited to give it a go.

vho

[yuzuha]

I have one of these http://www.microscopesusa.com/Vision.html
I got the 10x30 version with supplemental lenses and eyepieces so I can go get between 5x to 120x.
Fun for looking at a lot of other things besides knife blades too ^-^

Would be really cool if I could afford the trinocular version with the digital camera so I could post web pictures!

[epkmack]

Fred and others, in regards to "There is no such thing as a number of strokes or anything of that nature." How much do you use the diffrent grits percentage wise?
Is is something like 1000Grit 80% and 6000 grit 20% or is it more like 50/50?

[VHo]

hey, that was fun! /ubbthreads/images/graemlins/smile.gif worked the nortons for the first time. started out on the $20 chef knife, I'm sure my technique will get better, but that knife has never been sharper. so went directly to the powdered steel, seems you can feel the different angle of bevel, anyway no problem.

I was a little hesitant about getting into stones, but what a blessing! does that make me fully accredited?

thank you fred, your knife reviews got me going down this path a couple months ago, and my how life has changed - for the better! /ubbthreads/images/graemlins/smile.gif

cooking is a whole lot more fun.

vho

[Fred]

Glad it worked out. Cooking should be fun.

[barbouni]

I'm enjoying my stones as well. Just got the 15k Shapton to go with 1 and 5 and put a very nice edge on a few knives. I guess I do need a coarse stone after all, since it looks like I will be the official family and friends knife sharpener. What should I use for blades in very neglected condition?

L

[VHo]

What should I use for blades in very neglected condition? [ QUOTE ]


[/ QUOTE ]

a 200 grit or so, is what the experts around here have suggested. /ubbthreads/images/graemlins/smile.gif

off to work, have a good one.

vho

[yuzuha]

Well, I do a lot of experimenting with polishing the sides of blades (and sometimes just small blocks of different kinds of steel) so I use my stones differently than most. I'd say about 50-50 coarse/medium-finishing. Your coarse stones will wear much faster than the fine stones, but, unless you beat the heck out of your knives, you'll probably use the medium stones most (1,000-4000 grit). Also, if you've done a good job with the coarse and medium stones, it doesn't take long for the finishing stones to smooth out a bevel so your 80-20 guess doesn't seem too far off.

VHo, I use the microscope for looking at my handiwork. Since my eyes are not what they used to be, I also find a hand lens like this http://www.geo-tools.com/lens.htm to be quite helpful (mine is a metal one, but pretty similar). These are very easy to use while in the process of sharpening to see how I'm doing on profiling that edge or if I've removed the scratches from the preceeding stone and am ready to move on to the next one (also great for seeing that last vestiage of marker when doing the old magic marker trick on the bevels)

Barbouni: The Shapton 1k is pretty agressive (more than other 1k stones I've used) but I use DMT diamond 10x4 duolaps for really banged up stuff, but agree with VHo, something like that pink ceramic 220 brick, several places like Blade Gallery and Epicurian edge sell, would be good for grinding out chips and reshaping the edge of a damaged blade.

[VHo]

I can see where that microscope would be so nice to see what you're doing. I pulled out a cheap plastic magnifying lens to have a look, it helped a little. perhaps somewhere down the road I can afford the luxury of a microscope. maybe a glass magnifyer till then.

thanks,

vho

[barbouni]

[ QUOTE ]
I have one of these http://www.microscopesusa.com/Vision.html
I got the 10x30 version with supplemental lenses and eyepieces so I can go get between 5x to 120x.
Fun for looking at a lot of other things besides knife blades too ^-^

[/ QUOTE ]

"Can a human soul be glimpsed through a microscope? Maybe—but you'd definitely need one of those very good ones with two eyepieces."

Woody Allen

[yuzuha]

[ QUOTE ]
I can see where that microscope would be so nice to see what you're doing. I pulled out a cheap plastic magnifying lens to have a look, it helped a little. perhaps somewhere down the road I can afford the luxury of a microscope. maybe a glass magnifyer till then.


[/ QUOTE ]

Actually the microscope is pretty worthless to see what you are doing. You would skuzz it all up keeping it near your sharpening station so you'd have to clean and dry your knife, take it to the scope, then get the light and focus right. It is good for admiring your work after you are done, but not much use while sharpening.

Do try one of the 10x-15x hand lenses. This one http://www.geo-tools.com/lens.htm has gotten very good reviews and you can't beat the price (13.05) for the quality of it (some of the low quality ones aren't worth having) Here is a review of it http://www.njminerals.org/loupes.html

Much flatter field of view and way more magnification with less distortion than you can get with a regular magnifier.


You can also get them here
http://www.deakin.com/index.cfm?action=d...;product_id=102 (http://www.deakin.com/index.cfm?action=display&product_class_id=5&produc t_group_id=66&product_id=102)
http://www.egeology.com/magnifier.html
http://www.frostproof.com/catalog/meas02.html
http://www.kingsleynorth.com/skshop/search_results2.php?catID=310
and various places that sell jewelry making supplies or geology/prospecting stuff.

Just hang it around your neck so you don't have to hunt for it and can grab it easily while you are sharpening. Just put it close (about 3" ) to your eye and check your blade, drop it and go back to grinding. 10x-16x will show you an amazing amount of detail, though the 10x is a bit easier to handle and quite sufficient to see what you need to see.

[VHo]

that's in my price range. it is done! thanks for the advice Yuzuha. /ubbthreads/images/graemlins/grin.gif
it's been nothing but gold around here. I love this place!

vho

[mrsadm]

Thanks for the suggestion of the loupe, yuzuha. I just ordered one. I have a microscope but as you say, it doesn't really help you see much when you are sharpening.

[yuzuha]

Thanks, Hope you and VHo let me know how you like them.

I love mine, particularly since my eyes are not what they used to be, and I've not quite learned to read the little glints you can get off the bevel by rotating the blade under a strong light.

Oh, I've seen some people try to use them like an ordinary magnifying glass and that doesn't work too well, so here's a page on the proper way to hold one http://www.diamondhelpers.com/ask/0034-useloupe.shtml (alas, I've never found a diamond /ubbthreads/images/graemlins/grin.gif).

Those low power 3-7x loupes you hold in your eye like a monacle (there are also some that clip on to glasses frames) are also really handy when you need both hands free, like when you are trying to dig a sliver out of your finger /ubbthreads/images/graemlins/blush.gif

[VHo]

thanks for the loupe lesson! /ubbthreads/images/graemlins/grin.gif I see your point, that is very thoughtful and considerate of you. will let you know how it goes.

vho