stupid question #........oh hell i forget

S

sergeant69

Guest
anyway, decided to put a hold on the NWG until i retire in 2 years, for lots of reasons. by that time will have time and $$ to devote to doing it right rather than trying to cobble it together in a hurry and it not being right. in the meantime bought a D-5010 from TEXAS KNIFEMAKERS. i have decided that i am going to learn to sharpen on this thing or die trying (i live on a river and dull a lotta knives fast decimating the catfish and occassional deer and wild hog population). i have the edgepro system and like it but a jig/stone rig is so slow. the D5010 came w/a 220 belt and the first time outta the chute i sharpened a knife so sharp is scared me. so tried an old k-bar and not so good. guy at texas knifemakers suggested i get a MICRON FILM BELT in 600 or 900 as a final deburr/polish belt. all the stuff i read says a leather strop w/compound is the way to go though. so i guess my question is, after the 220 grit, and i see the burr etc etc, what next? 600 then 900 then leather strop on my grizzly 1x30" sander or...????? or a leather wheel? THANKS for the help.
 

rob45

Well-Known Member
You mentioned trouble with an old K-Bar even though you had success with another knife. How bad was the edge starting out? The most important thing starting out is obtaining the burr, but it has to be a consistent burr all the way along the blade. If the edge was really trashed to start, you may be better served starting out with a slightly coarser belt. This would allow faster, easier, complete setting of the initial burr and considerably prolong life of your 220 belt.
Also, something very important to keep in mind is the fact that different steels can have a huge impact on the ability to take a keen edge- some steels are more refined than others. Seems like some of them you merely have to put 220 to it and then strop it and you're done, while others require ten different steps in the sharpening process.
Relatively speaking, a highly refined steel will obtain maximum benefit from a detailed sharpening procedure, whereas with a less refined steel we may be wasting our time because "it's as sharp as it's ever gonna get".

I'm not familiar with your machine, so I do not know what belts are readily available to you. In any case, belts can be custom made if not available as stock in your desired grit.
Some belts are rated in grit, and others are in microns. I do not have a conversion chart in front of me, so these figures are off the top of my head, but they'll get you in the ballpark. I accept no responsibility for inaccuracies on conversion simply due to the fact that very few charts exactly agree, but the main idea is to go progressively finer (meaning a smaller number in micron or larger number in grit) without making too big of a jump in grit size from one step to the next.


I like to use the following method as a general purpose method, at least until I develop a feel for what each blade benefits from and what is wasting my time.

1. 100 micron belt for initial setting of burr. This is somewhere around 120-150 grit. Make sure you have a consistent burr along the entire edge of the blade. If you already have a reasonable edge that's simply dull, you may be able to skip this step.

2. 60 micron belt. This is somewhere around 220 grit. When done with this, you still have a sizable burr, just smaller.

3. Some people go to a 40 micron for this step, while others go to 30 micron. Regardless, it will be somewhere around 300-400 grit. After this step, your burr will be small, but you should still be able to feel it with your thumbnail, even though you may not be able to easily see it.

4. Something around a 20 or 15 micron belt. This puts you in the range of 600 grit. After this step it may be hard to determine the presence of a burr because it is so small as to easily be moved by your thumb pressure, so you may not even feel it. But rest assured it is there.

5. Now go to around a 9 micron belt. This will be somewhat equivalent to a 1000-1200 grit.

6. Finish up with the leather and polishing compound if you want. This puts final polish on the edge by removing the microscopic burr that you cannot feel.
Many people do not even use the leather/polish. You're pretty much on your own with this step, and it will probably require experimentation on your part. The reason is because not all polishes are the same. Probably the most glaring example is the black compounds. One source may give finer results than your last belt (9 micron/1200 grit), while another source may give results that are actually a step backwards. I have some black compound that seems like I just finished with 320! Not good when I just finished using a 1200 grit belt.

Probably the best thing to do is source your compound from the same manufacturer (this certainly includes your belts, too) to prevent the "grit designation discrepancy".

When sharpening on your grinder, do not use too much pressure. Let the abrasives do the work instead. Too much pressure will build too much heat.

Many people scoff at the idea of using 5 different grits before getting to the leather, but this method produces the best results for me. It doesn't take long, and the (finer) higher grit belts seem to last forever.

Yes, you can still get a "sharp" edge without doing it this way. If the 220 belt, 600 belt, and leather are all you have, it's still a lot better than a coarse/fine stone.
You mentioned using 220, 600, 900, leather as an option. That would probably work, but even better would be to put a 400 in there, too.
Your edge will be "the ultimate" if you follow the basic regimen outlined above. An edge refined in this manner should be sharper, last longer and be easier to maintain.

Many people have a hard time understanding this process because it is difficult to see what is happening since it is an edge. But here is a simple experiment to make somebody a believer:

Take two pieces of flat scrap steel of same composition. Try to polish both to a mirror finish, but use two different methods.
On the first one, use sandpaper in the following progression of grits: 220, 600, buff/polish.
On the second one, use 220, 400, 800, 1200, 2000, polish.
Three steps versus six steps, but the second piece (6 steps) will get done easier, faster, and have a much better finish.
And even though you're initially starting with twice the number of grits, you will actually have less money invested in materials to achieve the mirror finish, because with the first method you will use a ton of 600 grit paper to eliminate the 220 scratches, if you even can.

Sharpening an edge and polishing a steel plate are fundamentally the same concept- you're removing metal to make a surface more refined, but you're doing it for different reasons.

Notice that as you go finer in the abrasive (higher in grit), the bigger "jump" you can get away with. At the coarser stages, small jumps are best.
For example, jumping from 220 grit to 800 grit is not considered good. This is a "grit difference" of around 600.
But notice that it is perfectly acceptable to follow 1000 grit with 2000 grit, even though we now have a "difference" of 1000.
If sharpening, the reason for this is due to the fact that something finished at 1000-1200 grit is already shaving hair, etc. and it's harder for us to perceive the difference of the bigger jump.
If polishing, we are already detecting "shine" by this point, and our subjective human eyesight becomes the judging factor for further refinements. But if you skip too much at the lower (coarser) levels, you will always have those initial scratches still there, no matter how "polished" you make it, and the same lack of refinement will occur on an edge.


Maybe this is more than you wanted to know, but I hope it helps.

Good Luck,
Robert
 
S

sergeant69

Guest
right after i read this i watched a tutorial on KD w/a guy using a 1x30 sander and he basically did the exact same thing you say to do. belts are cheap enough that i can easily keep a supply on hand of the diff. grits. i timed it, and it takes 5 seconds to change a belt on my grinder. literally. so theres really no reason not to go coarser to finer. and reading ur post i realized that the kbar was MUCH thicker in the blade than the other one that sharpened so easily but i used the 220 grit on both as was all i had. well, i also had an 80 grit but didn't want to grind the blade in half. so anyway that is now solved/understood. more belts are on order. i tried 3 other blades and 2 got sharp in a hurry w/the 220 and a ceramic rod and the other so-so. so, i'm getting there. THANK YOU for the time and effort in your reply. much appreciated! learned a lot!
 

James Terrio

Well-Known Member
Lots of good tips in Robert's post! All I can add is, gosh 220 or lower is awful coarse for "normal" sharpening. Once you have the edge established the way you want, you'll rarely have to go that coarse unless you really knock the heck out of your edge.

Frequent touch-ups are always better than letting an edge get really dull and starting over. Think of a professional butcher or sushi chef who steels his knife very often but rarely has to touch it to a stone or belt.

I've recently read some interesting info about heat build-up when using belts, and how it can slightly soften the steel at the very very edge, even when you use caution. I don't think it's a huge issue, but it couldn't hurt to use a fine stone or strop to polish off any steel that might have been affected. Seems to me this is another good reason to employ a slight microbevel. Just a thought.
 
Last edited:
S

sergeant69

Guest
i agree. i would much rather "touch up" than "re-do". course sooner or later you have to re-do to some extent. so far, i have bought all my blade blanks (all 6) from one place. reason is that their catalog goes into lots of details on the blades, important to a knife know-nothing like me. their blades are stainless steel and an option they offer is the Deep Cyrogenic Tempering (-305F) treatment which they claim enhances the blade edge holding properties. is this a good option? are the claims true? i know these blades are a hell of a lot harder than anything i now have. thanks for the reply!
 

tedinatl

Well-Known Member
I spoke to Brad Stallsmith of Peter's Heat Treating about this the other day, and he said that he does the Cryo freeze as a standard part of his heat treating process, because it significantly enhances the edge retention of the blade. He specify how much (differs by blade, I suppose), but he did say it was enough for him to keep doing it.
 

James Terrio

Well-Known Member
I agree, cryo is worth the extra couple bucks on high-alloy steels. They need it as part of the quenching process to fully convert the steel to hard and tough material. :thumbup:
 
Top