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...
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:
Work a layer of jewelers rouge into the rough side of the leather.
Lay the strop on a flat surface, like the edge of your hobby bench or mount it to a piece of wood.
Lay the blade flat on the strop and then tilt about 20 degrees.
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.
Repeat on the other side of the blade (right to left, not shown).
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.
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.
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!