Sharpening pinking shears

[grepper]

My wife cleaned out her sewing room and found a box of 10 or so scissors and shears, most in need of sharpening.   Among them a pair of Wiss CC7 vintage pinking shears:
http://jwissandsons.com/1950s/PSC-12-50.htm

I had previously cut up an old, well-worn flannel shirt into small rags I could use around the shop, and used that material for testing.  The shears were so dull they couldn't cut the old, soft material.  If just folded between the blades and left little holes at the apex of each tooth.

Visually they did not look that bad, so I decided to have a closer look-see. 

I sharpened them first with the grinding wheel pretty coarse, and while I probably didn't need to, again somewhat less than coarse. 

Before sharpening I was surprised to see that even under closer inspection they still did not look all that bad with only minimal rounding of the edges, but were dull to the point of uselessness nonetheless.  After sharpening they cut perfectly smoothly and evenly from the first to the last tooth.  In the "after" picture you can see there is a little bit if burr visible on the edges.

While it's impossible to know exactly using my USB microscope, I suspect this is about 100x magnification:

Before:



After:

[mike40]

They certainly look smoother than the original. Do you have to hone these? We have a lot of dull scissors around the house and I really need to try sharpening some soon. I did sharpen my hedge clippers last summer and that worked out really well. I have tried sharpening scissors in the past on my diamond stones, but with any luck (or fun either).

[grepper]

Good to have you back Mike!

No, I did not hone them.  Generally, you don't need to hone regular scissors.  If you get them too smooth the blades tend to push what you are cutting along the blade when you close the blades.

Same type of deal with kitchen knives.  Sometimes, especially for things like tomato skin, a little tooth can be a good thing. 

Tormek does a great job with scissors.

[Ken S]

"fortuna favet fortibus" (fortune favors the brave).....Good job, Grepper!

Also, first-rate job of photography!

Ken

[Jan]

Well done, Grepper! Thanks for posting the result. 

Mike, I can also recommend not to hone the scissors edge. It is unequivocally recommended by Tormek (Manual page 65 in ver.10):



Please do not be surprised when the blade edge is more than the standard 60 degrees. My hair cutting scissors have 75 to 80 degrees and cut fine. I am large admirer of the scissors jig. 

Jan

[mike40]

Thank Grepper and Jan, good to be back and thanks for the scissors info.

[grepper]

After sharpening, don't close the blades to cut off the burr.  Instead, close the blades while holding them slightly spread with your fingers. While closed, pinch them together gently and repeat a few times. 

From what I've seen, the burr formed on scissors is very small and generally not a problem.  It does not take much to remove it if you feel it necessary.  So if you do drag it over some wood or something, you can do it very gently.

[Elden]

I have a Foley Belsaw 327 scissors grinder that I have used quite successfully to sharpen fabric shears with in the past. I believe  that machine compares to the Twice As Sharp if it is not the same.

It has a honing wheel on it. In regard to fabric shears, instructional material taught to hone one blade, usually the one that slid under the fabric. The second blade was left in the ground status. It did make a difference in the cutting action (more layers of fabric could be cut). There was no slippage of the fabric while cutting.

I know that the stock honing wheel on the 327 would not leave as finely polished surface as the honing wheel on the Tormek would. I do not have the scissors attachment for the Tormek try it, but I am curious how a pair of shears with one Tormek honed blade would work. In my thinking the one non polished blade will provide the needed "grip" to keep the fabric from slipping between the blades while cutting.

It would be something to try for an adventure.

[Ken S]

Good post, Elden, and welcome back.

Ken

[grepper]

As I remember, honing one blade is recommended in the Twice as Sharp manual, or maybe I saw it in one of their videos.

Lucky you!  That Foley 327 sure looks like a Twice as Sharp!  Then, maybe form follows function.

I almost bought a Foley 387 (I think that's the number) automatic hand saw blade sharpener once because it looked cool, and I thought it might be fun to restore and play with. Pretty big chunk of stuff to have sitting around mostly for entertainment... Then, sadly, sanity prevailed.

One thing for sure, those vintage tools sure hold their value!

[Herman Trivilino]

While it's impossible to know exactly using my USB microscope, I suspect this is about 100x magnification:

Nice photography, Mark. It really helps understand the sharpening process.

Imagine the millions of cuts that were made on those shears over probably several decades and maybe even a few generations of seamstresses. All that work gone with a swipe of the grindstone! 

They are now back in the shape they were in when your great aunt bought them, and ready for the next generations. The next time they need sharpening we probably won't be around, but our Tormeks will!

[Ken S]

Well put, Herman. (You sound like a man with a sharpening hobby.....)

Ken