Forever-Sharp Hobby Blade

by HilldaFlyer | May 4, 2014 | (19) Posted in Tips

Forever-Sharp Hobby Knife

Sharpening Hobby Knife Blades by HilldaFlyer


On a few episodes, Josh Bixler has mentioned the reason he uses utility knife blades is because they are the most economical (cheap, cheap, cheap). I too, have used snap-off blades, utility blades, one-sided razor blades and #11 exacto blades, etc. My preference is to use the #11 exacto blades, but like all blades they get dull because of use. My solution - sharpen them… I bet with a little practice you could even sharpen utility knife blades too. But with a forever-sharp exacto blade in a handle, there is no reason to be using a handle-less blade.


With a little searching on the internet, I found in the rocketry forum with detailed descriptions of how to sharpen hobby knife blades. After trying it, I’m a believer and have been using the same two #11 exacto blades for 6 months. That’s incredible…. Here is how...


Credits:

http://www.rocketryforum.com/showthread.php?37330-Sharpening-X-acto-blades

http://www.rocketryforum.com/showthread.php?20558-Best-Hobby-Knife-Evar!&highlight=leather+strop


Materials:

  • Hobby knife

  • Old Leather Belt (I got one at a used clothing store for $3). It is good to get one with a rough side, but if not, you can scratch up any leather with 60 grit sand paper.

  • White jewelers rouge (available on ebay for $3). Note: some people wrote about using chrome polishing compound. I have not tried this, but the principle is the same and should work.


Sharpening the blade:

  1. Work a layer of jewelers rouge into the rough side of the leather.

  2. Lay the strop on a flat surface, like the edge of your hobby bench or mount it to a piece of wood.

  3. Lay the blade flat on the strop and then tilt about 20 degrees.

  4. Drag the hobby blade across the length of the strop in a direction away from the cutting edge (left to right below) keeping the blade at the same angle. Repeat 5 to 10 times.

  5. Repeat on the other side of the blade (right to left, not shown).

  6. Your hobby knife is sharp again.



When the strop becomes shiny and black, it is time to give it a facelift. Just warm it up a bit with a hair dryer (oven, sun on a sunny day, don’t use open flame unless your name is David Windestål). After it is warm, scrape off the excess jewelers rouge with a one-sided razor or similar scraping tool (don’t use your hobby knife). Then I apply a new layer of rouge while the leather is still warm.


Tips:

I think the hardest technique to learn is how to maintain a constant angle between the blade and the strop throughout the entire stroke. If the angle is not maintained, the sharpened edge will be slightly rounded (i.e. dull). My advice is to go slow and develop a technique. You don’t have to push very hard across the strop, just enough pressure to ensure good contact.


Hey, the hobby knife handle above looks like wood, well - it is wood. After having so much success sharpening the blade in my aluminum exacto knife handle and not having to replace the blade every day, I built an exacto blade handle out of a dowel, just to see if I could, and it works great! I cut a notch in the end of the dowel with a scroll saw, fastened the blade in the dowel with a small screw (filed off the protruding point of the screw) and wrapped the notched end with fiberglass. It is very light. Follow link 2 above for directions on how to build your own hobby knife handle out of a bolt. Both forums are good reads if you want to sharpen your blades… I highly recommend it. 


Summary

Sharpening your hobby knife.

Use it up, wear it out, make it do or do without


Update October 2014 - For reference see Chris’ comment below - ChrisJ June 6, 2014

Thanks Chris. After reading your comment, I got to thinking that I may have a Arkansas stone. I grew up in Montana and used to go hunting. One of the items I packed was a knife, of course, and a sharpening stone. It was small but it got the job done. I rummaged through my old gear and loan behold, guess what I found… my sharpening stone and it was Smith’s Hard Arkansas.


I tried it out with mineral oil and I have to say that I am even more impressed with the edge the stone created. It is amazing, but after setting in on an angle, you can actually “feel” the grinding sensation turn into a gliding when the blade is flat with the stone. It takes about 5 to 10 strokes on each side and the blade is really sharp. 



I would definitely recommend getting a good stone. Thanks again Chris!

COMMENTS

1959cutter on June 1, 2014
great article! the chrome polish is the best as I make dentures and use truckers chrome polish on the final polish,and I recently discovered that my lathe mounted leather wheel puts a new edge on my #11 blades!(BE CAREFULL WITH SPINNING WHEELS AND SHARP KNIVES!)
I just cut out my kraken and three spitfires with the same blade yesterday
Mike
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Flyerguy455 on May 31, 2014
I use a sharpening steel also. I just keep it on the table while I am cutting. It is good to touch up a dulling blade, but I bet the strop will really get them sharp.

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rockets4kids on May 31, 2014
Nice! ;-)


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Bellows on May 31, 2014
Very Nice technique and I will try it. In the meantime....I have been using a sharpening steel which is a simple device used by chefs to keep their knives sharp.It works very well on my exacto blades and even my snap off blades from the dollar store. I have both the ribbed type and the diamond embedded type. Either one works great.LooseBruce
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HilldaFlyer on May 31, 2014
I'll have to try the steel. Do they come in flat pieces? I've only seen the round ones.
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PeterGregory on January 19, 2015
FYI - The Diamond and Steel are two different things. Diamonds take material off. Steels align the very last molecules of the blade material, so they aren't curled over. Steels are used after you use the diamond, or a stone.
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sailorJohn on May 31, 2014
I find the #11 blade has a tendency to wander, even when using a straight edge ,so I prefer a snap off blade for long cuts and save my # 11 for plunge cuts. I also have and old time box cutter that uses razor blades but don't use it any more. In my teens I had a job cutting mats in a picture frame studio and "had" to sharpen my blades on a white stone slow turning wheel, and it was a treat to be able to use a new blade to get the required results. Now they are cut by machine.. But I learned my lesson I only resharpen blades if I have to walk 10 miles through snow uphill for new ones.
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Simon milburn on June 11, 2014
white jewellers rouge, $3 , can you buy some for me, price triples if one lives in Australia :(

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HilldaFlyer on November 17, 2014
Simon, I think your money is best spent on a really good stone. I've used both now and the stone rules big time. I'm sure you can get some good quality sharpening stones in Australia. The jewelers rouge is a nice follow up, but is not necessary.
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Huggs on June 4, 2014
I like sharp knives as well as the next guy.
I own an Edge Pro Apex sharpener. I drew the line at #11 blades though.
I can get 100 #11s for around $5. It's not worth my time to resharpen them.
I know that sounds horrible, but I just can't see myself honing a 5 cent blade for even 5 minutes.
Cutting DTF doesn't strike me as requiring anything near laser sharpness.
Sharpening isn't free - I'll throw in an old belt, but the cost of the jewelers rouge or chrome polish will keep me in new #11s for years.
Best regards,
PCH
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adamD on June 7, 2014
where do u get your packs of 100 #11s
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Huggs on June 8, 2014
I just did a 2 min Google search -
Xacto brand 100 x #11 $12
No-name 100 x #11 scalpel blades with handle - $6.50
I haven't bought any for a while so it may take some searching to get down to $.05
Best regards,
PCH
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ChrisJ on June 6, 2014
Nearly all blades sold to the Hobby market are comparatively blunt!!

The best stone for forming and polishing the cutting angle is an Arkansas stone from America, better than all the man-made composites, its a (usually) white very hard stone, expensive, but you only need to buy it once, it will last all your life, mine has been in constant use for over 50 years.

You use with lots of oil, any oil will do cooking oil, linseed oil, mineral oils, but mineral oils are less smelly and less 'gooey' after a few years, engine oil, sewing machine oil all work fine, whale oil is the oil of choice, but you can't get it anymore (except in Japan).

Find the angle the edge has been ground at and polish all the grinding grooves out of it with the stone and lots of oil, the oil makes a cutting fluid when mixed with particles off the Arkansas stone, you always sharpen a blade or any action that is grinding the blade by pushing with the edge first.

Now your blade will easily cut a hair and slice through paper.

The final stage is stropping, stropping does not remove anything from the blade it uses friction to melt the blade molecules right at the cutting edge and drags the molecules over the edge forming a very hard 'wire' which breaks off and leaves an edge which is just one molecule thick, glassifying them and interlocking the molecules and should be done firmly with pressure in the opposite direction, away from the edge, and at a slightly steeper angle on a leather strop. In the past this was dressed with 'crocus powder' mixed with whale oil, the nearest you can get these days is jewelers rouge and Vaseline.

Stropping takes just a few seconds and the edge will last for weeks, the action of air molecules actually sharpens the edge, cut throat razors were often sold in sets of seven, you used a razor once a week then rested it for the other six days when it would re-sharpen itself! About once a year you'd take them to the barbers and He would strop them for you.

Is it worth all this palava? You bet, the edge is just one molecule thick, you can't get sharper, the blade now cuts on contact (you have been warned), very little pressure required and it cuts in the direction of the pressure, with the grain or across the grain makes no difference, the blade is actually safer to use as it's predictable, now you can cut a hair lengthways with precision, I don't why you'd want to, but you can :-). Stropping also hardens the edge so it lasts a lot longer and polishes it so it cuts a lot cleaner.

Cheers Chris
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PeterGregory on June 10, 2014
Thank you Professor Sharp.That was an awesome explanation. Hard-earned info, I am sure.
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HilldaFlyer on June 6, 2014
Chris - That is great information!
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HilldaFlyer on September 4, 2014
Chris - I looked through my old hunting gear (I grew up in Montana) and I discovered the sharpening stone I never used was an Arkansas hard white. Since the discovery, I have sharpened my hobby knifes using the stone first, then strop. All I can say is WOW! All it takes is 3 to 5 strokes on each side and a quick run across the leather. I haven't done any scientific measurements, but it seems to stay sharper longer. Thanks again for your great insight. I'll enjoy a resharpened knife, forever.
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HilldaFlyer on October 30, 2014
Chris, I've updated the article with a couple of pictures of my stone. I am truly impressed with the ease of sharpening. Great advice.
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DerekWest on June 2, 2014
Excellent info! I've been using a stone to re-hone my blades and have found that a strop makes them LASER sharp!
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ratdog on February 27, 2015
I really like using the diamond hone/stick for sharpening my knives/blades. You can usually find them pretty cheap in the sporting goods section of Wal-Mart. I have a small pocket one that cost me about $5. I have used it for years. If you don't like to buy jewelers rouge, you can make your own with powdered mica and oil or Vaseline. Mica is used for polishing glass and mirrors. Another trick (from the old double edged shaving blades) is to rub your blade around the inside of a glass drinking glass. This is like super fine stropping. It was used to make your shaving blades last a lot longer.
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Kdobson83 on May 24, 2016
What is being described here is not sharping at all. To sharpen a blade u must remove metal like with a bench grinder. What is being done here is actually honing. You can buy hones on the internet all day for a few bucks. I hone surgical scissor blades every day at work. Good post though.
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HilldaFlyer on May 25, 2016
Thanks for the comment... Call it what you will. The stone and strop do remove metal, although very small amounts. If it didn't the blade wouldn't get any smaller. In the past two years I have replaced the blade 3 times because they got small.
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Forever-Sharp Hobby Blade