Getting to final edge thickness by hand?

B

blitz134

Joined
Sep 18, 2013
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7
Looking for some advice...

Finally got my first three blades back from HT (1095). I took the edge down to ~.030" based upon feedback on the forum. I should have called the heat treater first since it seems he used some decarb paste since there was barely any scale to remove once the blades came back. If I would have known this, I would have at least taken them down to .020". So now my edges are pretty thick compared to the .010" that I hear recommended prior to sharpening. I have worked on one for a good bit with 120 and made no notable progress in thinning the edge out while maintaining the full flat grind.

Outside of a drill press and a band saw, these have all been made by hand (i.e. I don't have a grinder). Is it a losing battle to try to remove this much material after HT by hand sanding? I am a really patient person, but I already have a lot of hours into each of these and am honestly losing my motivation. I wouldn't be surprised if I've got nearly 16 hours into each blade, just to get to heat treat. All of the other posts on this forum quickly resort to talk about getting to final edge thickness using a grinder...not much talk of purely hand made knives.
 
With 1095 and 120 grit it should be just a matter of a little elbow grease to remove 0.010 off of either side. What is your sanding set up like? Paper? Lubrication?
 
We all seem to do this a little differently, and we learn as we go. Making a couple of knives at one time means that whatever you may have learned in doing the first completely, doesn't come up until you finish that group. Knife make by any means can be a slow process and usually becomes very personal to each of us in how its done. Your expectations of yourself doing this will decide if you will continue or not. Remember you are barely underway and have hardily scratched the surface on a couple of steel bars.
Perhaps if you were to read the stickies above if you have not or read some of threads by others you will find some answers.
Frank
 
Nicely said Frank. Great wisdom. Knife making isn't for everyone. If it wasn't challenging a lot of us wouldn't do it. For me it's about personal growth. Jess
 
I agree with Matthew; Put some 120 grit on a flat block of granite or something and sand away.

If it is just plain taking too long, you could mount a sanding drum (fine grit sleeve) in the drill press and carefully run the bevels through lengthwise.

For what it's worth, I have way more than 16 hours each into the 2 blades I'm doing (by hand) right now.
 
Not sure what your using to do bevels but before I had my belt grinder I used a filing jig to do my bevels and then heat treat and if they needed a bit more removed on the bevels I'd use my filing jig again but I had some 150, 220, 320 PSA shop rolls and I'd slap sand paper on the file and go at just like I did to make my bevels and work up thru the grits before hand sanding. It might take you 30-45 min per side to remove .010 and get up to a 320. In fact I used to leave some material and do it that way anyways. Let me know if you'd like me to post some pics of my old setup.

Jay
 
Blitz, these guys are giving great answers and suggestions. I also work with minimal equipment, cutting bevels with files and doing any and all finishing by hand. When "grinding" pre heat treat, it just takes practice to hit that perfect thickness to where it won't warp during HT but isn't too much of a PITA to bring down post heat treat. On most all carbon knives I make, .020" is the maximum I allow pre heat treat, and .015" gets darn close to minimums. Not much of a window. But as some of the guys have said....we all have a way that works for us.

Also, I had made a "petty" knife for my father a couple years ago. I decided to "grind" post heat treat. 1095 hardened to about 61HRC and .070" at the spine. I used 120 grit paper, and was surprised how quickly it went. Stick with it! You'll get it there!
 
To answer a few questions:

Using Rynowet paper wrapped around a 2" wide block and lubed with a spray of WD40. I sand until I get a noticeable reduction in "toothiness" of the paper on metal. Blade is clamped to a block of wood in a vice.

Frank, I've looked through the forum and stickies quite a bit, but sometimes details are missing and most responses still seem to focus on using grinders. I realized the downfall of working in batches near the end of the third blade since I had concerns come up that I knew wouldn't be answered for some time to come. Luckily, the other two blades have less material to remove since I did go thinner on those.

I have no doubt I'll finish these, but I just was trying to get a feel for how long this should take to remove what seems like miles of material at my current rate. 30-45 minutes?!?! I've already got 2x that on one side and I'm not even close! Maybe I'll keep the calipers out to measure progress. It just seems that I didn't make ANY after my attempt.

I am happy with the results so far and am proud to show them off even now and say that they were completed to this stage by hand. The forum has been invaluable for me and I'm still optimistic about the outcome.
 
I have this to add with your reply. Good doin's !!!!!! You did mention a good sand paper to use, but what grit? Are you back at 120 or at least 220?
Sounds to me that after all you are coming along very well. You just didn't realize it was such a labor intensive, time taking job.
Frank
 
I started out doing some kit knives. I would clamp the paper down to something flat and solid and then sand the knife. You can get more force on it this way.
 
Unless you are talking about very large blades it should not take more than 10 minutes per side to get it down .010 with 120 grit.

First I would ditch the wd40, you are trying to abrade. I would use windex as a simple solution. The fluid is to help "float" the swarf off the blade and paper. I find oils, while leaving a nicer finish tend to prolong the process. Friction is our friend here. Ideally we would sand dry if it didn't clog the paper after just a few strokes, so using something that floats off the swarf, while minimally lowering the coefficient of friction is what we are after.

Next, use your sand paper like it is free. As soon as you aren't getting aggressive cutting, ditch it.

Third, I would make sure you can get some good leverage on your sanding setup, ideally with straight arms and using your body for weight and legs to push, in other words your blade when clamped in your sanding setup should probably be at a level between the bottom of your rib cage and above your belly button. (If you follow this, please, please, please make sure your blade tip is not hanging over your block as losing your balance could lead to impalement)

Finally I would ditch the 2" sanding stick. 1" would work much better as we want friction to facilitate aggressive cutting and a narrower sanding stick gives us more pounds per square inch of force on the blade.
 
It will get easier Blitz. You'll find the way that works well for you. For instance... Matthew doesn't use WD-40, I find it outperforms Windex(water based lube).

I have someone working with me in the shop. When he started, it took him all day to hand sand a single blade up to a 400gt finish. 3-4months(40-50blades) later and he's doing 5 blades in a hour... with better results!
 
Hi Rick, that's impressive. .. If you would resume, what are the things done different that lead to such an improvement in hand sanding?
Thanks from my sore wrists ;)
 
I'm going through this right now, except my blade isn't heat treated yet. I've come to dislike working with sandpapers. It seems I spend as much time cutting papers to size, swapping them out, etc., as I do actually working on the blade. So I prefer to use sharpening stones. I have a synthetic Japanese ceramic stone of 1000 grit (more like 500 grit American, if I'm remembering the numbering systems correctly) that removes steel faster than 320 grit silicon carbide paper. And it doesn't clog up or gall if I keep it wet. It makes thick black swarf with just a couple passes, which shows how quickly it's removing steel. I use Simple Green cleaner to keep things from clogging with paper or other stones, since it seems less corrosive to the steel, but water seems to work fine with this particular stone. Many makers also use EDM stones or various rods & sticks for tight areas. https://www.congresstools.com/catalog/categories/get-category/?id=72
Keep them lapped flat and they can give a very flat and true surface; much better than I've been able to accomplish with sandpaper.
 
Actually I use a homemade mix that I "borrowed" from Kevin Cashen and I love how it works. Just water, denatured alcohol, dish soap, and tsp. He has some pretty sound reasoning behind the ingredients, so I tried it and fell in love.

One of these days I will get around to trying the kool mist as suggest by Fred Rowe... one day, when I find some time in between studying....:(

From this post. http://www.bladeforums.com/forums/showthread.php/523422-wet-or-dry-sand?p=5215495#post5215495
 
Matthew... That's funny. I use almost the same mix in my "all-purpose" shop spray. I wanted something to clean blades prior to and after etching. I also use it for drill coolant and wasp killer.
 
Yeah it really comes in handy... it's kinda like the Marvel Mystery Oil of the knife shop lol... even though I keep MMO on hand as well! :D
 
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