Need help sharpening a Curtiss F3

Grandmaster

Grandmaster

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Jun 14, 2015
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So I just got my Curtiss F3 Medium with CTS/XHP, it didnt came razor sharp, it tears thru paper, no clean cuts, I just want to re touch the edge, but I tried my Spyderco Ultra Fine Stones, did always touch up nicely any blade, Hinderer, Sebenza, Giant Mouse, Emerson, Strider, ZT's no problem, but they do nothing to my Curtiss, how can I just touch up the edge??

thanks

(I own the sharpmaker, DMT aligner and Guided Worksharp)
 
One possibility is that your current sharpening rig is set up for a more acute angle than the factory edge of your F3. If this is the case, then your stones may not be hitting the edge apex, but instead are hitting the shoulders of the edge.

My F3 came to me from the manufacturer with a fairly obtuse edge angle of 56 degrees inclusive:

i-2LK4v8w.jpg


If you are using a Spyderco Sharpmaker set up for an edge angle of 40 degrees inclusive, then it will take many strokes before your stones begin to affect the edge apex.
 
Grandmaster said:
So I just got my Curtiss F3 Medium with CTS/XHP, it didnt came razor sharp, it tears thru paper, no clean cuts, I just want to re touch the edge, but I tried my Spyderco Ultra Fine Stones, did always touch up nicely any blade, Hinderer, Sebenza, Giant Mouse, Emerson, Strider, ZT's no problem, but they do nothing to my Curtiss, how can I just touch up the edge??

thanks

(I own the sharpmaker, DMT aligner and Guided Worksharp)
Click to expand...

Hi,
Do you mean it won't slice paper printer paper?
Spyderco ultra fine very high grit stone (~3micron)
you use it if your edge is already very very sharp (like almost/barely head hair whittling )
If edge wont slice paper you need something much coarser

If the edge is rolled then you could unroll and burnish using ultra fine but you need a slightly higher angle
 
Should I use the ultra fine stone? and if so, should I use the pointy end or flat end?

thanks
 
Grab a sharpie...color the entire edge of both sides. Give each side a few passes and see what's going on.


Sent from my iPhone using Tapatalk
 
Grandmaster said:
Should I use the ultra fine stone? and if so, should I use the pointy end or flat end?

thanks
Click to expand...

Hi,
What are you trying to do?

If you're using sharpmaker triangle stones, stick to the flats and avoid the corners , as you need a much lighter (impossibly lighter) touch on the corners.

If you're trying to unroll an edge, strop 1-2 pass per side on the flats, then 1-10 ultra light feather edge leading pases per side, and it should be as sharp as it was if it was rolled,
thats burnishing/steeling/realignment/deformation only

If you're trying to sharpen, a quick sharpening using a high angle to create a microbevel,
start with sharpmaker medium stones or coarser
 
Im trying to get it super sharp, it came not so sharp, try the dmt XXF and got a nice shaving sharp, should I use the Spyderco next? or just green strop?
 
Regardless of what tool you use, or what stones you use, it's essential that you hit the edge apex. If your factory edge angle is like mine, then with the Spyderco Sharpmaker set at 40 degrees, it will be difficult to hit the apex unless you work long and hard to remove a lot of steel. A few light strokes will have no effect, because the stones will not touch the apex -- they will hit behind the apex, on the shoulders of the edge profile:

i-M6gWFDv.jpg


If your freehand skills are good, you could work around this constraint by adjusting the angle at which you hold the blade in the Sharpmaker.
 
Last edited:
Thanks Cyrano, I was able to hit themapex thanks to your first image, I adjusted the dmt and finally got a hair shaving sharp, in your experience with curtiss f3 ctx/ xhp do the edge last a long time, cause it took a while to sharpen

Thanks guys for your help!!!!!!
 
I'm glad to have helped.

I've not yet used my F3 enough to have an opinion on edge retention. Even if I did, I expect your results could differ, based on how you've created your edge.

I hope you enjoy the knife! I certainly love mine.
 
Here's the edge I put on my F3 using a WorkSharp Ken Onion/Blade Grinding Attachment and stiff belts:

i-J2hQFQJ.jpg
 
David Curtiss wants people to know: "... They can send the knife to me anytime for sharpening. It's always under warranty and always free."
 
Thanks for the magnification pics Cyrano! It verifies exactly what was happening to my F3. Used my wicked edge with a sharpie and just couldn't get the stones to bite the edge---it always hit the shoulders. Got so bent out of shape that I set the stones to 40 and went to town. After much grinding I finally got SCREAMING sharp. Didn't realize that was what was happening until I unclamped the F3 and noticed the I finally ground down the wide shoulders and reprofiled the edge. It looked nicer with a shorter edge 'profile', but at least it now it cuts way way better.
 
I would have said use the DMT Aligner. And make sure you have at least 4 stones for it- Coarse-XX Fine (the X & XX coarse just make it quicker). This is IMHO, the best little starter/travel kit on the market. It's what I used to get my very first TRULY SHARP edges. And when I started to see what was actually "sharp"! No guess work. It gave me a good starting point to focus on the bevels and keeping the edge centered.
 
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