Getting an Edge after HT

Z

zaustin13

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Feb 18, 2011
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Got my first knife back from ht the other day. Prior to ht, I wet sanded it with 400 grit and left an edge about the thickness of a dime. The knife is cleaned back up and has the finish I want on it but the edge is still the same thickness. What is the best way to get the edge sharp at this point. If I use sand paper it seems like it is going to take forever. Knife is 1095, fixed blade. Thanks for any suggestions.
 
Start with 220 paper and lubricate it with a spray of Windex. Use a backing block and work the blade bevels down to about .010". At that point, start going up the grits to whatever finish you want. When done finishing the blade, the edge will be almost sharp. If it is sharp, take a few strokes across a piece of sandpaper to blunt the edge.

Now, tape up the blade and do the handle. When finished it is time to make the knife sharp.

Add the secondary bevel by sharpening it at the desired angle. For a user, about 15 degrees per side ( 30 degrees included angle), for a slicer 10 degrees per side. Any sharpening style or system will work for this final edge.

NEVER DO THE HANDLE WORK ON A SHARP KNIFE !
The final edge is the last thing done.
 
A dime mike's out at about .050. Your unsharpened edge should be around .015, or even less if possible, when you sharpen it. You are not going to remove that much metal by hand sanding. You are going to need to grind, or power sand it some more. I would suggest next time figure on having to grind more off before hand sanding to 400 grit. Don't take it down more than 220 grit before HT, and 180 grit should be fine enough. You are just wasteing your time and energy to go any farther. I take my 01 blades to finished thickness before HT, but 1095 may be different. Also may depend on who treats it, and how.
 
I usually recommend about .030 - .040" before HT and .010" before sharpening.

Sandpaper and a backing block will make the extra go away, but it will take good paper ( wet-or-dry, or rhino-wett) and a lot of elbow grease.

A grinder just does what you do by hand - just faster. That is good if you know what the desired result should be, but for the first several knives, I always suggest doing it by hand.
Too many new makers get a KMG to start on and then are disappointed that an expensive machine makes such poor knives. ..........It is not the tool, but the hand that uses them. Train your hands first, and get better tools in time as you need them.

To start with all the tools you need are:
two or three files,
a stack of metal working sandpaper from 100 to 400 grit,
a 2X2X6" block of hard wood,
a piece of known knife steel,
a place to work and a clamp of some sort to hold down the blade.
 
I respectfully have to disagree. For him to remove .020 from each side, to arrive at .010 at the edge by hand sanding on a HT'ed blade, in my opinion, would be be a exercise in futility and a detriment to his resolve to make any more knives. He needs a power method to get it down that far in any amount of reasonable time, if it is nothing more than a hand held belt sander locked upside down in a vise. Hand sanding is for finish work. Not stock removal. Especially after HT.
 
I have to agree with Stacy... I take down bevels all the time with a sanding paddle and 80-220 grit emery tape. I have a grinder and more often than not, reach for the paddle. The whole time I worked with him, Wally Hayes didn't let me touch the grinder, even for roughing. Forge close to shape, file and sand. Grinders and other machinery should come AFTER you learn how to make a knife. Starting from the ground up is the best way.

Rick
 
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Just to muddy the waters. With a small blade and a half-height grind or such it should not be a huge problem to reduce the edge that much. It will be tempting to take a flat grind (if that is what you have) to a convex in this situation...
A big bowie with a 2" wide blade and a full flat grind out of 3V would be daunting to take that much off of by hand. No thanks.
 
LRB, perhaps you are accidentally moving the decimal one place??? Also, we are talking about 1095 here. Stainless steels can be much thinner before HT.

We are only talking about removing about .010-.015" per side to get the final dimension on a normal flat ground knife.( if you removed .020" per side from a .030-.040" edge blade, you would have a full flat grind to the edge, and the edge might chip easily.)

For those who can't think in thousandths of an inch - Lets do some experimenting.
Get your good micrometer out of the shop, and then pull out a sheet of printer paper. Probably 20# bond. Look at it sideways, Pretty thin stuff !
Now measure three sheet at one time for their thickness.....I'll wait while you do it .....OK, probably about .010-.012". Now, does it look too hard to sand that much off a knife? Look at these three sheets sideways, that is about the edge thickness you want to sand down to before sharpening for users....maybe two sheets on a slicer.....one on a sashimi.
Just for fun, grab ten sheets...that is the final edge thickness before HT. You can get away with five sheets when you have more experience and with stainless steels, but .040 is a good edge thickness to avoid warping for 1095.

On most knives, I take the blade to 400 grit pre-HT. I do 220 and then 400 post-HT. The 220 step takes off about .010" and the 400 step takes off about .005" ( per side). Each grit takes about 10-15 minutes max. Much less on a smaller blade. The usual post-HT time to hand sand a normal size blade is about 30 minutes. At that point it should be dead flat and have no scratches.

The last sentence holds a lot of the reasons for removing .010-.015" per side. A knife just out of quench and temper has at least two things wrong with it. It is almost surely not truly flat, and probably has some scratches on the surface. If the knife was made from high carbon steel and done in a less than optimal HT setup, there is also going to be a thin layer of de-carb. If you just touch it up with 400 grit paper after HT, it will probably look OK, but will not be completely flat...or have the deeper scratches removed.....and may still have some de-carb. Taking off the top skin for .010-.015" will take care of these three things pretty well.

I have made hundreds of blades where I removed much more than this by hand. It takes very little time. On a sword blade, you may take off as much as .100" in shaping the blade.( OK, that takes a lot of time)
Also, every person who I have made up a starter kit for, used these thickness numbers, and produced a fine knife by hand sanding.
 
I thought we were discussing Zaustin13's blade which he stated the edge was the thickness of a dime, which is .050. .020 + .020 is .040, leaving .010 at the edge. That's a lot of hand sanding on a HTed blade, but to each his own.
 
Can I assume you do not have a belt grinding machine?

Fred
 
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