Burrs/Overhoning

[binder]

I have a question about overhoning and burrs. As far as I know overhoning is when a person creates a burr that can break off. How does a person know when they have overhoned or have a burr? I have been trying to sharpen a razor. I have tried using various amounts of pressure, including using minimal pressure. I find the razor will only get so sharp, but I can't get it sharper. It doesn't give a comfortable shave; doesn't cut well, and have razor burn. I have been using the Norton 4/8K hone. I'm just wondering how much overhoning has to with honing or what other things could be the problem. I mostly use alternating strokes each way with the razor.

Thanks

 

[Gamma]

Not enough info.
Post pix of the blade if you can.
Did you set the bevel before going to 8k?
do you have a 1k or something in that zone?
What was the condition of the blade before you tried to hone it?
Was the stone lapped flat on both sides?
Did you soak the stone before using it?
Did you read any of the honing threads or watch any of the videos?
Alternating strokes of what kind, how many, on which side of the 4/8k, etc?
Did you do any edge tests while you were honing? If you did, what were the results?

Chances are, you'll need to set the bevel and you can do that on the 4k, but it's easier to do on a 1k.
Most sharpening happens on grits before 4k. If you're not getting sharp then your bevel work might not be done.

 

[cb91710]

Overhoning is talked about a lot on forums, and I am not convinced that it is common.

Someone runs 200+ laps and then blames the bad edge on "overhoned" when in fact the problem is they never properly set the bevel. They spent an hour creating a very fine polished surface, a couple of microns behind the edge.
IMHO, it is EXTREMELY difficult to hone up a burr if you are using alternating strokes.
Circles and half-laps are great for the initial stages, but once the bevel begins to form, the process needs to move to full strokes.

 

[Doc226]

I am not a believer in overhoning at higher grits. I do think you can create a burr with lower grits but as long as the strokes are even side to side it should not be a problem.

I did have a blade a little back that would not last a shave. I mean after a few strokes the edge was dead. I think this was due to a foil edge. This razor had been honed on synthetics and then I tried turning it to a JNAT. It had a good bevel and felt sharp but just would not last.

I always set my own bevels now usually on natural stones. Have not had a problem since.

I digress. I think the fellas ahead of me hit the nail on the head.

 

[alx gilmore]

Not enough info.
Post pix of the blade if you can.
Did you set the bevel before going to 8k?
do you have a 1k or something in that zone?
What was the condition of the blade before you tried to hone it?
Was the stone lapped flat on both sides?
Did you soak the stone before using it?
Did you read any of the honing threads or watch any of the videos?
Alternating strokes of what kind, how many, on which side of the 4/8k, etc?
Did you do any edge tests while you were honing? If you did, what were the results?

Chances are, you'll need to set the bevel and you can do that on the 4k, but it's easier to do on a 1k.
Most sharpening happens on grits before 4k. If you're not getting sharp then your bevel work might not be done.

Binder
You have sparked what is essencially the nut of a treatise here on honing as Gamma has so adroitly laid out. Although sharpening or "honing" as its refered to here is a craft that anyone can learn, the basics are the same from person to person and blade to blade. Compounding errors are the bugaboo, and the resulting dull edge is the end result. A reset bevel can set a lot square real fast so you can go on and practice on refining your technique, but careful observation and notation of each and everyone one of your hand movements is needed in order so that they can be implanted into your muscle memory as repeatable.

I look at overhoning as the distortion of a perfectly set bevel. Some distortion has to be accepted, and this is why we have strops. But they are only useful if the distortion is of the level as Doc refers to as the foil edge. Using synthetics like I do as a bevel setter is quick but they are agressive cutters. A false edge or foil edge is the result of a very light hand where as a burr is the result of a heavy hand or coarser grits. But as long as your bevels are essentially flat your finishing stones can work down through the heavier scratches to leave a finer pattern and then the strops can do their work.

Alx

 

[binder]

Not enough info.
Post pix of the blade if you can.
Did you set the bevel before going to 8k?
do you have a 1k or something in that zone?
What was the condition of the blade before you tried to hone it?
Was the stone lapped flat on both sides?
Did you soak the stone before using it?
Did you read any of the honing threads or watch any of the videos?
Alternating strokes of what kind, how many, on which side of the 4/8k, etc?
Did you do any edge tests while you were honing? If you did, what were the results?

Chances are, you'll need to set the bevel and you can do that on the 4k, but it's easier to do on a 1k.
Most sharpening happens on grits before 4k. If you're not getting sharp then your bevel work might not be done.

Thanks for replies

Sorry I can't take pictures. I don't have a camera available.
I have 3 razors that I have tried to hone:
1. 4/8 half hollow
2. 5/8 full hollow with slight smile on spine and edge
3. 5/8 full hollow: I think slight warp: edge lays flat on one side and I need to roll the edge on the other.
Hones: 1200 King, 4/8K Norton

The 4/8 I got from Whipped Dog and it shaved good, but I dulled it and tried to hone it again. Tried using the 8K, but went down to the 4K after that. The other 2 I got used and honed starting with the King stone.

I lapped and soaked all the hones before using.

I've watched all the honing videos I could find on Youtube: Alex Jacques, heavydutysg135, gssixgun, hi_bud_gl, ken Rup. Also read a number of articles. I think I understand the basics, but don't know why I'm having problems.

I start out at times using half strokes or chisel strokes, but finish with alternating x strokes. I can't remember exactly how many strokes I've done on each razor, have lost count. I've done 100s of strokes on the 1200 (feels good on TNT). Can pop arm hair dry at skin level; can't seem to get better than that. Then about 100 on 4K and 8K. I've gone through that a few times, then stick with 4/8K.

I tests I have used are the TNT and the TPT. Tried running the thumb parallel with the edge, but didn't find I could tell much with this, so usually test it like a knife.

 

[Gamma]

Cool

1.2k - popping arm hair is good. That's about what you'll get off that grit. Maybe a bit better, perhaps not.
At 4k, you refine the bevel until it's ready to finish.
When you go to the 8k, with minimal pressure, you should not see heavy swarf marks coming off the blade.
If you do - then your 4k work isn't done - go back.
Then - try again on the 8k.

Couple of things - check the bevel during the 1.2k phase, make sure you're hitting across the whole blade.
Do that repeatedly during each grit session. You should see the scratches from the last grit being polished out. If you see gaps or spots where that's not happening then you're not hitting the bevel evenly.

Maxing out on 8k takes some skill. A light hand and careful strokes work best for me here in my house with my gear.

To me - a maxed out Norton 8k edge is basically useless. I can shave with it but not well enough to want to be doing that. Esp on ATG passes.
I always had to hit a Norton 8k on Crox or diamond to get a decent shave. Others will contest that. Not sure why - they don't shave my face. I do and I know what works and what doesn't for me. As they say YMMV.

The bulk of the sharpening is going to be done at the 1k-4k stage. Be sure you're maxing out there.
Some pressure on the 1.2k is probably ok, but that stone is soft and if the blade is a hollow grind you could run into grief.
Firm pressure but not heavy pressure. You need to cut steel so there should be some oomph behind the stroke.
I find less pressure to start on the 4k to be best, and lightening up on the pressure as the edge refines.

The 4/8 half hollow is probably going to be easiest to get done first.
Smiles and warps offer challenges that you might want to wait to deal with since you have another option.

 

[jeness]

+1 to everything Gamma wrote, good advice there. I don't like plain 8k edges either, paste helps a lot there. After some time you will want to get a finisher, when you can get good edges off the 8k and some pastes.

 

[binder]

I honed the 4/8 razor with 4/8K Norton. I had some paste on balsa that I got from Whipped Dog: 0.3 chromium oxide & 0.1 Iron Oxide (Is this too much of a jump from 8K?). I did 20 laps with each. There still was some pulling. I then used tape and made a micro bevel: about 80 laps with the 8K and then the pastes, 40 with chromium and 25 with iron oxide. The shave from that was much better. Some razor burn, probably need to improve technique. Don't know if I am at the max, but am doing better. I would still like to figure out why I couldn't get the edge without the micro bevel, will have to work on that.

Thanks for advice