Sharpening with wet dry sandpaper

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Hey guys,

So I was at home depot today and decided to pick up some 800 grit wet dry sand paper to sharpen knives with. I got home and tried it out on my cts xhp manix 2 and it took off a ton of steel and didn't make it any sharper. I sharpened at a roughtly 20 degree angle on each side free hand. What am I doing wrong? I have no experience sharpening with sandpaper so really broad advice would be great. I used the sandpaper dry
 
Check KnivesShipFree.com for their sharpening videos. Youtube has some good ones too. VERY light to no pressure is key. Also make sure you are raising the spine just until the edge starts to touch. Too much pressure and to high an angle will round the edge of your blade. You'll probably also want to go up to at least 2000 grit to get a good edge. I like to finish with a strop as well.
 
Spyderco knives generally come with 40* inclusive edges, so if you were sharpening at 20* a side, it shouldn't have taken "a ton of steel" to come off for it to get sharp. If it does need a lot off for whatever reason, it'd be a good idea to start off with a lower grit. I usually start with 60 or 120 grit for full reprofiling.

Are you sure you're keeping the same angle each pass?

What are you using the sandpaper on?

How hard are you pressing with each pass?

SoLo has some good videos on youtube about freehand sharpening. Using sandpaper really isn't any different than using a stone (assuming you aren't convexing it). I'd suggest taking a look at those if you aren't used to freehand sharpening.
 
Hey guys,

So I was at home depot today and decided to pick up some 800 grit wet dry sand paper to sharpen knives with. I got home and tried it out on my cts xhp manix 2 and it took off a ton of steel and didn't make it any sharper. I sharpened at a roughtly 20 degree angle on each side free hand. What am I doing wrong? I have no experience sharpening with sandpaper so really broad advice would be great. I used the sandpaper dry

What exactly is "a ton of steel"?
You should really use a guided sharpening system to begin with, unless you want to get good at freehand sharpening, practice on old knives - not your new/good knives.
 
I have the sand paper glued to a 2x4. And the manix 2 im sharpening doesn't have a factory edge, I purchased it sharpened. A ton of steel just means that it is taking off as much steel with each pass as a diamond sharpener. Which I consider to be alot- there was alot of powder on the sand paper when I was done. I may be pressing too hard. I think Im just going to buy a sharpmaker. I'm not very good at sharpening but I can usually get face shaving sharp on a 600 grit stone followed by my medium ceramic and a good strop on the leather belt.

I mainly got the sandpaper for my big choppers. I'll watch some of the suggested videos and see if I can figure out what I'm doing wrong.
 
A "ton of steel" is certainly more than one knife! That's too much pressure! (((:D)))

Ok, sorry. That wasn;t fair.

Here's what I use, sharpening trailing edge (convex knives like Bark River or Falkniven) like singularity said. But you certainly can sharpen cutting "into" the sandpaper. I know because I sharpen my wood chisels that way, except that the substrate (instead of leather on wood) is 1/4" plate glass.

Side one:
convex-01.jpg


And flipped over:
convex-02.jpg


I would start at 800 or 1000, maybe 1500, unless the edge is knicked.
 
I have the sand paper glued to a 2x4. And the manix 2 im sharpening doesn't have a factory edge, I purchased it sharpened. A ton of steel just means that it is taking off as much steel with each pass as a diamond sharpener. Which I consider to be alot- there was alot of powder on the sand paper when I was done. I may be pressing too hard. I think Im just going to buy a sharpmaker. I'm not very good at sharpening but I can usually get face shaving sharp on a 600 grit stone followed by my medium ceramic and a good strop on the leather belt.

I mainly got the sandpaper for my big choppers. I'll watch some of the suggested videos and see if I can figure out what I'm doing wrong.

Maybe the surface of the wood is irregular. I use the same system, but first, I had a woodworker use a disc sander to sand the surface of the piece of wood and then I glued a piece of leather to the wood (about 2 mm thick).
In some cases, I place the sandpaper on glass. I don't use water, I use oil
(3 in 1 for instance).
Hope this help.
 
I'm horrified you would use a sprint run Manix 2 to try out a new sharpening system that you have never used before :eek:. I personally have gotten inconsistent results with sandpaper but I think the key is to use minimal pressure like you would on diamond stones.
 
What brand sandpaper was it?

800 is starting to get fairly fine when speaking of W/D sandpaper, you should also be getting at least a clean shaving edge.

The ton of steel you see being removed is not all steel, half of it is disloged abrasive from the paper. Sandpaper is a little like a diamond stone and a natural water stone in the way it works. Like a diamond because the surface starts out very aggressive then gradually breaks-in as the excess grit is removed. And like a natural stone because as it breaks-in the abrasive becomes finer yielding a more refined finish to the piece.

I usually go by my own rule of 50%, once the paper has lost 50% of its aggressive action I know its time to move on.

Also don't mix worn paper with fresh paper. For example don't move from fresh 800 to worn 1k and remember that each time you use a piece it will cut slower and produce a finer finish.

Your backing shouldn't be that much of a issue but getting a piece of glass would be much better and give you a better feel.
 
I think 800 is way to high a grit to "sharpen" with, that should be used for putting the final polish on. Start with 320 grit for steel removal, then 400 and 600 before finishing with 800. You can go even higher, but only really for polishing.

I've been using wet/dry papers for close to 20 years, both on glass and mouse pad depending on whether Scandi or convexed blade and I've always started with 320 grit.
 
Ok guys I think what I was doing wrong was using too much pressure and sharpening the wrong way. I just sharpened my dogfather with the edge trailing and gave it a good strop and it will cleanly shave my leg and slice paper. Thanks for the pointers! If I can get a dogfather sharp with this method I think I can get just about any sized blade now :)
 
And just sharped my tomcat (a recurve) and was able to get it near face shaving sharp :) I'm really liking this system! I think with a higher grit I could put a really mean edge on most of my knives.
 
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