Creating a burr

KKOLA:  If it’s your first few knives, please be aware that the diamond stones need to be “broken-in” before you can expect best results.  The diamond particles are attached to their substrate in a plating process.  To assure full coverage, there is a substantial excess of particles laid on.  Those particles not actually touching the substrate will have to be knocked off.  Eventually, the particles will uniformly cover 100% of the surface area.  Until then, you can expect rough surfaces and less than hoped-for results.  Since each stone is an individual, the time required to complete the breaking in process is variable.  It could be ten knives or fifty, depending on your technique and pressure applied.  Generally, the guys here recommend sticking to less expensive knives during this period.  Some of us go out to thrift shops and buy a few knives to practice on and to move the break-in process along.  I had an 800 grit stone once that had a few really bad spots that refused to break off.  I eventually chucked up a section of plate glass and within a dozen or so strokes the surface of the stone was beautiful.

After five years, I’m on my third 400/600 and 800/1000 stones.  When I start with a new stone, I dig out some old, cheap knives and my glass plate.  When they’re well broken in, I’ll put them in my lineup and remove the old stones.

A stone not yet broken-in will feel and sound scratchy and rough.  A well broken-in stone will feel smooth – like a fine grit sandpaper.

You will probably not notice a burr with the coarser grits, or when using alternating strokes.  Maybe not during the break-in period either as the high-sitting grit will tend to rip the burrs off.  When you transition up to 400 grit, use alternating strokes until you think you’re close to the apex, then try ten strokes on one side, then feel for a continuous burr on the other side.  Once you have a burr full-length, switch to the other side and repeat.

We all have our preferred technique for using the burr as an indicator that you’ve reached the apex this one is mine and certainly not the consensus, but I thought it would give you a start.  A burr tells you that it’s OK to move on to the next grit.  If you haven’t reached the apex, moving on to a higher grit will be a waste of time and effort.

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Alan, wickededge

All the above is good advice…. my .02… from your description it sounds like you reached the edge, like tcmeyer said, if you’re alternating strokes, you’ll probably never feel a burr.  And because the stones are new, they’re a bit “rough”.

If you’re sure you’re at the edge, I’d go try just the finer stones again… say start at 400g and go up from there.  Spend enough time at each level to insure that it’s smoothed out the previous grit.  Test the edge at 600g, it should be able to easily slice paper at that point, and no longer feel ‘jagged”.  If you’re not sure you’re at the edge, recheck using what EvilTwin posted.

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wickededge

kkola wrote:

Thanks everyone..I do believe that I may have been a bit too acute, as EvilTwin noted, and may have had to remove more steel than necessary and never getting to a burr, but rather a jagged edge. This forum is going to be a great tool if just a few guys are willing to step up as I saw here. I was also not aware that the break in for these stones was as extensive as tcmeyer stated. That is a bit discouraging, but I hope the broken in stones will be fine performers for some time after break in. Thanks again for your help.

Don’t be discouraged… When I was teaching engineering to 4th and fifth year students in their co-op phase, I could tell when my students were not getting it… so I attack a position from different angle. As a teacher, nothing is more rewarding than to see that light bulb go off in your student’s face when they ” get it”.

There is more of a science to knife sharpening than a novice might think but its not so insurmountable that anyone can not get it.  when I first came here I said.. what all this science? is just like putting a point on a stick.. cave men could do it.  <i>Its a little more involved than putting a point on a stick.</i>

In two months, I went from knowing nothing to knowing enough. Now my curiosity drives me into the science. There are some very qualified people here to help you. I am not qualified, because while I can sharpen a knife I have not taken it to the science. Most of the learning will come with experience. Knowing what works and what doesn’t work.  Also there are some tricks, you may find along the way. For example. I thought using wet n dry #2000 grit sandpaper wet would be good, but after some experimenting, I found that the more I used a dry piece of #2000 grit , the more worn it was, the better it worked at refining the bevel. Don’t be too in a hurry to learn it all. Learn some things to get you to the next level and experiment with touch and feel, also pressure. See how light pressure and firm pressure effect your technique. This is how I’ve approached this discipline. Understanding what is going on, will help turn that lightbulb on.

Welcome to the forum.

Bill aka ET

kkola wrote:

Thanks everyone..I do believe that I may have been a bit too acute, as EvilTwin noted, and may have had to remove more steel than necessary and never getting to a burr, but rather a jagged edge. This forum is going to be a great tool if just a few guys are willing to step up as I saw here. I was also not aware that the break in for these stones was as extensive as tcmeyer stated. That is a bit discouraging, but I hope the broken in stones will be fine performers for some time after break in. Thanks again for your help.

Getting a “jagged edge” should mean you were at the edge, so while it never hurts to double check, I think it’s more likely it just needs to be refined.

Also, should have mentioned before… use light pressure… that will alleviate some of the roughness issue, especially during the “break-in” period.  Diamonds in particular, don’t need a lot of pressure to get the job done.