Can't get reasonable edge on 1095 on sandpaper

D

damib

Joined
Jul 7, 2021
Messages
119
Hello,
as I've already stated on the forums, I am quite new to sharpening, but I've sharpened a few knives and tools now (carbon or stainless). I am sharpening my knives on sandpaper with edge trailing technique with success. Today I noticed that my Tops CAT is seriously dull and can't cut things like flowers without problem. So, I've picked up 800 and 1200 grit sandpaper and I've been sharpening on bot of them for at least 4 hours, but the sharpness is only insignificantly higher. I tried the sharpie thing and I am sharpening all the way to the edge evenly. Where is the problem exactly? Should I try lower grit? I've been unable to build a burr and bring the knife to hairsplitting sharpness before, but it at least sliced paper and I don't really know where the problem could be now. Can you determine the edge and the burr by optical means at home somehow?
 
damib said:
I've sharpened a few knives and tools now (carbon or stainless). I am sharpening my knives on sandpaper with edge trailing technique with success.
Click to expand...
I would start with what you did to sharpen with success. I would start at a lower grit if my knife was "seriously dull." One Eighty or 220 grit is a good starting point. What brand, type and grit sand paper are you successful with?
 
9D2D89BC-A060-4C8B-A3AC-655447DE87CB.jpeg
8A82C2DA-0EC6-494C-B546-B83D836DDFD0.jpeg

Convex finishing kit.

D damib the TOP’s knife probably has a very abuse edge - never seen a TOP’s that didn’t. You might want to do the heavy lifting with coarse stones prior to fine tuning with sand paper. Sandpaper re profiling is possible, takes a very long time. Lower grits, coffee and a sharpie are helpful. scottc3 scottc3 recommended some good stuff as well.
 
Luetheg, at my age tool boxes are running out of room... never thought about putting stickers on the microwave... just need to warn the sons if the mrs "owns" the microwave ;-)...
 
I really like DLT trading. So much that most things I use daily have a DLT sticker 😂. I’m not being paid to promote them - they are awesome though.
 
scottc3 said:
I would start with what you did to sharpen with success. I would start at a lower grit if my knife was "seriously dull." One Eighty or 220 grit is a good starting point. What brand, type and grit sand paper are you successful with?
Click to expand...
It's some relatively cheap generic sandpaper from hardware store. You can't practically buy 3M paper here, but I've had success with that sandpaper from hardware store. I think that it maybe won't be so generic after all. They just don't advertise the manufacturer, but many of the sandpapers here are from German brands like Bosch.
 
Glue or firmly affix the sandpaper to a hard backing (hardwood, stone, glass), for best results. If the sandpaper is just laying atop a hard backing and not firmly attached to it, the paper tends to lift or roll or otherwise move under pressure from the edge, and it rounds off the apex. This is likely the most common cause of sub-par results when using sandpaper.

The softer mousepad / cushioned methods do well for convexing the grind behind the apex. But for finishing the apex itself, it's ALWAYS better to use a hard backing (or better yet, a stone) to make the apex as crisp as it can be.
 
Obsessed with Edges said:
Glue or firmly affix the sandpaper to a hard backing (hardwood, stone, glass), for best results. If the sandpaper is just laying atop a hard backing and not firmly attached to it, the paper tends to lift or roll or otherwise move under pressure from the edge, and it rounds off the apex. This is likely the most common cause of sub-par results when using sandpaper.

The softer mousepad / cushioned methods do well for convexing the grind behind the apex. But for finishing the apex itself, it's ALWAYS better to use a hard backing (or better yet, a stone) to make the apex as crisp as it can be.
Click to expand...
Thanks for your advice. I've been having success with relatively hard mouse pad, but I've been thinking about sticking the sandpaper to something. I've also come across some sticky diamond sandpaper designed for knife sharpening, but it's so expensive that it would be better to buy Arkansas stone.

I've bought 220, 380 and 600 grit sandpaper. Used sharpie a lot. Still no burr. I've been able to make the knife slice the paper again, but it would do it only after a couple of tries. Could it be that maybe the burr is just so small that it's not perceivable by typical techniques for burr detection? I think that I will have to smuggle it under the stereoscopic microscope somehow and look at the apex, because if I shine a light on the edge, there are like two shiny surfaces. Maybe I did somehow introduce a microbevel or sort of convexed the edge? Remember that the mousepad is quite hard and I am using relatively low pressure.
 
Most likely the edge needs a good bit of metal to be removed to get a crisp apex.
Edge trailing on sandpaper could take a while especially 800/1200 grit.
 
willc said:
Most likely the edge needs a good bit of metal to be removed to get a crisp apex.
Edge trailing on sandpaper could take a while especially 800/1200 grit.
Click to expand...
And with 220 grit? I am kinda concerned about removing too much because I don't know how much time/strokes it can realistically take to apex the edge without removing too much steel.
 
Specs on the TOPS CAT knife seem to show it's a pretty heavy (thick) blade @ 0.160". So, assuming the steel behind the edge is also fairly thick - and it often is on tactical knives like these - it may be worth using the 220-grit to apex it. The thicker grind near the edge will also be more prone to convexing at/behind the shoulders of the edge bevels. Need to keep the angle conservatively LOW - less than the current edge angle - to avoid or minimize risk of rounding off the edge. If trying to maintain and hold the original edge angle on sandpaper, it's much more likely the apex will be rounded off in doing so. A low-held angle will take steel from the shoulders of the edge bevels - that's almost always a GOOD thing, to improve cutting geometry by thinning the grind behind the edge.
 
I'd recommend gluing the sandpaper to a hard flat surface like said above. This stuff just takes a while to get down. Sometimes a long while. The 800 grit is way to high to start at. That's a fine finishing paper. I don't use sandpaper, I have in the past, but my sharpening progression goes 50 to 100 grit (depending on how bad the edge is), 140 grit, 300 grit, and 600 grit. After 600 grit I strop it on leather for a few minutes and I'm done. I like to have a little toothiness to my edges, especially on a knife like you're sharpening.
 
LimpCroissant said:
I'd recommend gluing the sandpaper to a hard flat surface like said above. This stuff just takes a while to get down. Sometimes a long while. The 800 grit is way to high to start at. That's a fine finishing paper. I don't use sandpaper, I have in the past, but my sharpening progression goes 50 to 100 grit (depending on how bad the edge is), 140 grit, 300 grit, and 600 grit. After 600 grit I strop it on leather for a few minutes and I'm done. I like to have a little toothiness to my edges, especially on a knife like you're sharpening.
Click to expand...
Exactly how much time are you talking about? All the manuals on the internet say that 2-3 strokes with 220 grit should do the job, so I am kinda afraid that I would grind it down way too much with let's say 50 strokes.
 
damib said:
Exactly how much time are you talking about? All the manuals on the internet say that 2-3 strokes with 220 grit should do the job, so I am kinda afraid that I would grind it down way too much with let's say 50 strokes.
Click to expand...
Watch for a burr. Don't count strokes at all. Focus on making sure the paper is hard-backed and secured, as I mentioned earlier - that makes the paper work more aggressively (faster), with the hard & secure backing. Keep the angle low and held as consistently as you can. And look or feel for a burr after every stroke or two. At 220-grit, a steel like 1095 or any low-alloy stainless at the hardness spec'd for this knife (HRC 56-58) should produce an obvious burr as soon as the edge is apexed. The only way you might not see a burr is if there's too much angle variation and the edge is rounding off before apexing.

Extremely hard steels in the 60s HRC or harder sometimes will shed burrs almost immediately due to the brittleness of the steel at high hardness, so it's difficult sometimes to detect those. But this blade isn't hardened to that extent, and the burr should hang on long enough to either see it or feel it.
 
Last edited:
It depends if you're trying to reprofile an edge to get a new angle or keep the same angle and just sharpen. However I've never seen a knife get sharp with 2-3 strokes on anything save a powered belt sander. It takes a whole lot more than that, especially if you can't cut paper yet. There is no number of strokes I can tell you, but it'd be more like 50 on each side or more in my opinion. You won't remove too much steel believe me. I take my 50 grit diamond stone to my edges for sometimes 100 strokes and it still doesn't remove any noticeable amount of steel behind the edge. The key to sharpening is you want your knife to be smoothly cutting through paper every time when you're done with the lowest grit (your 220 grit). That's where your knife gets sharp. Any grits above that just polish your already screaming sharp edge. I'd warn about going up too high in your grit progression while you're learning though because once you have your sharp 220 grit edge, the longer you stay sharpening the more chance you have of accidently rounding off your edge.
 
Obsessed with Edges said:
Watch for a burr. Don't count strokes at all. Focus on making sure the paper is hard-backed and secured, as I mentioned earlier - that makes the paper work more aggressively (faster), with the hard & secure backing. Keep the angle low and held as consistently as you can. And look or feel for a burr after every stroke or two. At 220-grit, a steel like 1095 or any low-alloy stainless at the hardness spec'd for this knife (RC 56-58) should produce an obvious burr as soon as the edge is apexed. The only way you might not see a burr is if there's too much angle variation and the edge is rounding off before apexing.

Extremely hard steels in the 60s HRC or harder sometimes will shed burrs almost immediately due to the brittleness of the steel at high hardness, so it's difficult sometimes to detect those. But this blade isn't hardened to that extent, and the burr should hang on long enough to either see it or feel it.
Click to expand...
Yup OP, follow what he's saying here, it's all about the burr. It can be very hard to detect. The best way I've found is to shine a flashlight on the edge perpendicular to the edge from the spine. It'll show any burrs that you can't feel.
 
damib said:
Hello,
as I've already stated on the forums, I am quite new to sharpening, but I've sharpened a few knives and tools now (carbon or stainless). I am sharpening my knives on sandpaper with edge trailing technique with success. Today I noticed that my Tops CAT is seriously dull and can't cut things like flowers without problem. So, I've picked up 800 and 1200 grit sandpaper and I've been sharpening on bot of them for at least 4 hours, but the sharpness is only insignificantly higher. I tried the sharpie thing and I am sharpening all the way to the edge evenly. Where is the problem exactly? Should I try lower grit? I've been unable to build a burr and bring the knife to hairsplitting sharpness before, but it at least sliced paper and I don't really know where the problem could be now. Can you determine the edge and the burr by optical means at home somehow?
Click to expand...
I would recommend you pick up a stone like the Norton combination India, it has a coarse and fine side, or a combination Crystolon, either one will serve you well. Affordable at less than 25 bucks for a 8x2. A stone will allow you to take edge leading and trailing strokes with out the fear of cutting your paper and no need to lift the knife on each stroke, things will go much faster for you and it will be a lot easier to maintain your angle and raise a burr. These stones are all over the place at pawn shops and used tool places for dirt cheap. Just get one that isn't dished if you go used.

I think this guy is a member here? I'm not sure, but it's a really good style and method to emulate.
 
LimpCroissant said:
Yup OP, follow what he's saying here, it's all about the burr. It can be very hard to detect. The best way I've found is to shine a flashlight on the edge perpendicular to the edge from the spine. It'll show any burrs that you can't feel.
Click to expand...
Are you saying that the second reflection above the edge is actually the burr?

Well, as to my progression. I've been sharpening for 2-3 hours now and although I tried to identify the burr, I counted the strokes and it was like 200 strokes on each side for 220 grit, but if the burr is the second reflection above the edge, then I was there little bit before. Then 100 stroke on 400 grit and 100 stroke on 600 grit. The knife isn't still shaving though. I also noticed that the paper I tried to cut wasn't exactly the best kind to cut, so I tore up some newspaper. It now cuts the paper fairly well. I've also done some food prep with it and I am satisfied with it. It cuts onion and fancy bread without too much problem or destroying them. It feels more like razor edge when in contact with skin. I will start from 50 grit sandpaper next time and get the sandpaper glued properly to some glass. It's reasonably sharp for me right now I'd say as I will be using it mainly for mundane EDC task in next 3 weeks.
 
damib said:
Are you saying that the second reflection above the edge is actually the burr?

Well, as to my progression. I've been sharpening for 2-3 hours now and although I tried to identify the burr, I counted the strokes and it was like 200 strokes on each side for 220 grit, but if the burr is the second reflection above the edge, then I was there little bit before. Then 100 stroke on 400 grit and 100 stroke on 600 grit. The knife isn't still shaving though. I also noticed that the paper I tried to cut wasn't exactly the best kind to cut, so I tore up some newspaper. It now cuts the paper fairly well. I've also done some food prep with it and I am satisfied with it. It cuts onion and fancy bread without too much problem or destroying them. It feels more like razor edge when in contact with skin. I will start from 50 grit sandpaper next time and get the sandpaper glued properly to some glass. It's reasonably sharp for me right now I'd say as I will be using it mainly for mundane EDC task in next 3 weeks.
Click to expand...
Hey sorry I just saw this. Yes you'll see the burr reflect the light from the flashlight. You have to have the light facing the right way though. Imagine setting the knife flat on top of a table, and then you shine your flashlight from the spine to the edge. If theres a burr there, you should be able to see it
 
You must log in or register to reply here.
Back
Top