Too hard to hand sand?

scott kozub said:
This is really weird. A buffer would remove the sharpie.

The belt isn't slipping is it? Never seen it happen but I wonder if the pressure against the platten is causing the drive wheel to slip on the belt and essentially stalling the belt.

Are you slack grinding or against a platten? Is slack grinding, you may only be hitting the edges. Are you throwing sparks?
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I’m grinding on a platten and I’m throwing the occasional spark. The belt is not slipping tho.
 
Richard338 said:
Since no one has mentioned this, let me guess...it is a very wide blade with large flats?
One of my very first projects was a big Cutlass type thing in A2. It came back from HT at 60 hardness and when I started with 180 and then 120 grit, it seemed to be just polishing it and not removing much. I had to drop to 60 and make firm passes to finish the grind. The huge flat bevels had been draw filed before HT.

This post seemed strange at first since I now routinely grind after HT, even a katana in 3V, but then I remembered my beginner project...
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It’s a 2inch wide chef knife so it’s width obviously tapers towards the tip. This sounds a lot like what is going on. I have tried all different speeds and pressures but the only thing that seems to work is a ceramic 120. I have also tried an AO 220 and a30/A45 Trizact belt with ultimately no luck grinding near the spine and edge. So I bought 220 ceramic and I’m going to try to work ceramic as high as it can go.
 
ren01228 said:
Can you post pictures, or even better a video on here? I saw you mentioned your Instagram but not everyone is on there including myself. Might help us understand what’s going on more, because it really doesn’t make sense to me. Might be something super obvious your just overlooking.
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Yea I will try and get a photo up sometime tomorrow.
 
Ok update I have no god damn idea how to put photos on here. However, I thing I figured a few things out. Sense I have the steel to heat treat all rough and didn’t care about the finish I think I left some 36 grit marks in the blade. This paired with my frequent changes from 120 to buffing belt to 220 provided for a very very slight slack grind due to the give on the thick buffing belt. This caused the 36 grit lines Near the edge and spine to not go away. I figured this out because I have another blade from the same heat treat place and I just took my time and did not use the buffing belt and did not have this problem near as bad. 5 hours in the garage and I finally have the blade hand sanded to a 600grit. Conclusion I’m an idiot and stainless steel sucks! Also, does anyone have any good 120 belt recommendations for after ht? Mine blow
 
ok here we go I figured it out. This is what my 220 belts are doing after I fixed the slack grind issue.
 
I use Norton blaze and do all my grinding post ht. I do 90% of my grinding with a 60 grit belt but will be going back to 36 grit for my next order.

I full flat grind to about 0.010 to 0.015" bte before slack grinding the final bit to get a bit of food release. Takes about 20 minutes with a fresh belt but I'll often start with a used belt to start the bevels. At about 0.007 I change to a 120 to clean it up and to to as close to a zero grind as possible. I go up to 400 on the grinder.

Total time for a 7" chef 2" wide in AEBL at 62-63 HTC including final finish handsanding to 800 grit is about 2 hours and I don't think that's fast.

Stainless steel should not be a pain unless your using something live s90v which I personally have never tried.

For hand sanding I start with 120 dyno wet and that takes the longest at about 20 to 30 minutes or so before it's ready for the next grits. The worst spot is always by the heel. The next grits go pretty quick assuming I don't slice my self open on the thin edge like I did last week.
 
scott kozub said:
I use Norton blaze and do all my grinding post ht. I do 90% of my grinding with a 60 grit belt but will be going back to 36 grit for my next order.

I full flat grind to about 0.010 to 0.015" bte before slack grinding the final bit to get a bit of food release. Takes about 20 minutes with a fresh belt but I'll often start with a used belt to start the bevels. At about 0.007 I change to a 120 to clean it up and to to as close to a zero grind as possible. I go up to 400 on the grinder.

Total time for a 7" chef 2" wide in AEBL at 62-63 HTC including final finish handsanding to 800 grit is about 2 hours and I don't think that's fast.

Stainless steel should not be a pain unless your using something live s90v which I personally have never tried.

For hand sanding I start with 120 dyno wet and that takes the longest at about 20 to 30 minutes or so before it's ready for the next grits. The worst spot is always by the heel. The next grits go pretty quick assuming I don't slice my self open on the thin edge like I did last week.
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wow that’s fast. So would you say it’s odd that it took me 1.5 hours to get it to 220 and 3hours to hand sand it to a 600? Also did that picture show up it doesn't look like it did.
 
I just finished a 6.5" santoku and I spent way more time getting to 220 then getting to 800 from there. The problem was not so much getting rid of scratch marks, but I had little dimples in the blade that took a long time to get out. I have no idea how I managed to create the dimples. They reappeared going from 120 to 220. I'd say probably 1.5-2h to get to 220 and very quick after that, maybe 30-45 minutes for the first side and half of that for the second side. For the second side, I quit constantly checking for scratch marks and just very quickly went through six pieces of sandpaper before even looking at the blade. At 600 grit, I started using a fairly thin hard piece of rubber between the sanding block (aluminum) and the paper. After 800 grit, I used a bit softer and thicker backer and just did a few pulls with 600 and WD-40. Very nice even finish. Of course, I promptly messed that up while gluing on the handle, but that's a different story.

I don't see a picture in your post. Have you seen this thread from the stickies? The imgur site has changed slightly since that was posted, just click on the "New post" icon near the top left.
 
I think the key is to get it as clean as possible on your first grit whether that be 36 50 or 60 grit and do as much as you can on that grit. The next grit is to remove scratches, and clean up any hollows or divots. In doing this the bte thickness should be very close to final. Every grit after that should be very fast as they are just removing scratches.

The blade should look almost finished before starting to handsand. As soon as I do 3 to 4 passes with a 220 on sanding block I see some scratches and hollows. The heel is always the worse and I spend 90% of my handsanding there.
 
Ekim knives has a very good tutorial on grinding chefs knives. I like to start at the top. I get a grind line that angles down from the spine towards the heel. I then keep grinding against the platten so that line slowly moves towards the heel but I try to maintain the same grind angle. This will be the same angle as the line that is shown in the video above. Doing this helps to develop a natural distal taper. Some will lay the blade lengthwise against the platen or disk to keep it flat.

 
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