How often do I change an X-Acto Blade?

Discussion in 'How Do I...' started by Szdfan, Feb 28, 2012.

  1. Szdfan

    Szdfan Member

    So I keep reading that when it comes to building paper models, you should change your blades often. Is there general rule of thumb about how often I should change them? How can I tell that the blade has gotten too dull? Do I need to invest in bulk packs of blades?

  2. Szdfan

    Szdfan Member there a way to sharpen xacto blades, or is it better to just buy a new blade?
  3. Psyscape

    Psyscape Member

    I re-edge my blades when working with wood as it's somewhat more forgiving than card (in my opinion anyway). I bought a small scale modellers mini bench grinder to do this, which comes in handy for various other tasks as well - such as edging metal, sharpening the wife's scissors etc. :)

    For card work though - and I've not been doing this very long - I find it easier and better to just change the blade. There are various places to buy blades on the net (Amazon is a reasonable source) and they're cheap enough that it doesn't hurt very much.

    As for telling when one is getting blunt. Personal judgement mostly should tell you. But telltales are where the blade is spreading the card when cutting (leaving small ridges on the sides of the cut) and when you have to apply more pressure to get the same level of cut, or when the blade is dragging.

    Ideally you shouldn't have to apply to much pressure in order to be able to cut, otherwise you stand a chance of tearing smaller pieces or getting uneven edges. Not to mention the chance that the blade might slip and either damage the model or the user.

    All in my inexperienced opinion of course.
  4. lehcyfer

    lehcyfer Member

    I use Olfa AK-3 knife which I find perfect for work in paper. I almost never buy new blades though - instead I sharpen them again and again, and even if the pointy end breaks off I grind the back of the blade with my dremel to get the sharp point, then sharpen the blade again.

    How to sharpen the blade? In paper work the blade rarely is dented - so sharpening it is more like smoothing than grinding. Using VERY fine sandpaper I move the blade as if I was cleaning it's side on the sandpaper, in direction towards the blunt edge of the knife - like on the linked part of this youtube movie.

    I covered one side of my steel ruler with fine sandpaper, using double-sided adhesive tape and sharpen the blade on it, with the ruler lying close to the edge of the table.

    When to stop sharpening? You can see that a knife is blunt when looking at it's edge directed towards you, in light of a lamp you can see it's edge shining. Well honed edge is all but invisible.

    Additionally the sandpaper stops my ruler from slipping when I use it for guiding the knife when cutting paper - allowing for a more precise and easier work.

    I use fresh knives very seldom - for extremely demanding tasks, and to switch to a new knife when the old has worn out.

    It goes without saying that it's very positive for my budget :)
  5. Zathros

    Zathros Guest

    I use scissors for most cutting. I have a really nice collection. Sometimes only an Exacto will do, but I purchased a 500 pack at a yard sale for almost nothing and still have to many to count left. The cutting boards (the Green Ones. I have an OLFA) will really help your blades last. If I can get off my arse and start using my Cameo Silohouette cutting machine, my cutting will become extremely limited. :)
  6. Psyscape

    Psyscape Member

    Awwww, I'd love a Cameo, but the wife does that eye-rolling thing that women seem to have as an innate skill. You know, the one where the eyes roll all the way into the back of the head and there's the accompanying tut tut noise which indicates that one is asking for something waaaaaaay not likely.
  7. Zathros

    Zathros Guest

    My "Mommy" purchased mine for me. I almost feel ashamed to say that, but she really likes the hobby. My Mom is 87, and considering her background, she is an amazing women. In the 1960's, she made Gyroscopes for Hamilton Standard. I remember when I showed her an Oscilloscope I purchased. I thought I knew something. She starts telling me about the time base, to be careful with the probes, etc. This is from someone who has a very heavy accent when she speaks, and definitely does not look like a person who knows what she knows.

    I am ashamed to say that this Winter has been a bad one for me, so I have not done anything with this machine. I hope that will change soon!
  8. Psyscape

    Psyscape Member

    My mother doesn't understand my hobbies. She thinks the end products are nice, but just doesn't get why I spend weeks threading pullies, sewing sails and generally months building a model. All that time... for what? Then I suppose it's understandable, she worked in manual labour for her whole life which paid for her retirement, her house and furniture and she owes no money to anybody. While I waste mine making little wooden boats and things. :D

    However, I am happy, I've managed to get my wife hooked on card modelling as well. She's busy figuring out how to add wooly hair to a Manny the Mammoth card model she made. *smirk* Now to work on the kids...

    Perhaps in a few months time I will be able to convince her that an automated cutter would be a good investment. ;)
  9. cgutzmer

    cgutzmer Active Member

    I use scalpels - much sharper,much higher quality metal. I can cut up an entire kit of 10 pages easily with one blade so long as I am careful not to press too hard. They are a bit brittle. My fav part of scalpels is that they are sharpened on both sides which reduces the paper mounding to one side.
  10. Dented Rick

    Dented Rick Human

    I buy #11 X-acto's from Hobby Lobby, then temper them myself. I can cut up to 20 pages of parts before needing to change a blade. 20 blades for $3. gotta love it
  11. Zathros

    Zathros Guest

    Do you heat them red, then quench them in a 30 weight oil, or something similar?
  12. Dented Rick

    Dented Rick Human

    Heat them red, then drop in a small bucket of water. then I reheat and let gradually cool down without dipping in the water
  13. lehcyfer

    lehcyfer Member

    I understand that the second reheat is not to red...
  14. Szdfan

    Szdfan Member

    Thanks for the replies.

    A couple of follow up questions --

    • What's a cameo? Is it like the cricut?
    • What's the advantage of tempering a blade? What kind of heat source do you use?
    • Is a blade a blade? I found a good deal at Amazon for a generic Xacto #11 style blade. Are generics ok, or would I be better off paying more for the Xacto blades?
  15. Zathros

    Zathros Guest

    You will get much better results with 30 weight oil. The viscosity of water is too thin and the heat boils the water away too easily. The causes uneven tempering of the steel. You may not even need a second dip. This was something I learned about 25 years ago when I was working in a aircraft instrument company. We had to harden small parts. Oil was the rule.

    From what I understand the second reheat is to relax the metal from the shock of the initial tempering. You could try putting clay on the back side and make miniature Katana exacto blades. :)
  16. Psyscape

    Psyscape Member

    Yes, the Cameo is very similar to the Cricut, without comparing the two I couldn't really say what the differences are except price.

    Advantages of tempering a blade is that the edge lasts longer, however, inexperienced people will likely make the metal more brittle as a result, rather than stronger, so it is not something to be approached casually.

    In my opinion generic blades are just fine. I use both and there is little difference except perhaps the xacto holds an edge for a little longer. The difference in price does not equate to lifespan though so overall a saving can be made using generic blades.
  17. Dented Rick

    Dented Rick Human

    The second reheat is to relax the metal. Heating then instantly cooling the metal fatigues it making it brittle. and yes, I reheat the second time to red :)

    Tempering the blades makes them stronger, and able to hold the sharp edge longer. I use a Bunsen burner similar to the type used in labs on tv. corny but effective, plus I can temper 10 blades at a time :)

    I'll definitely try the oil, although I don't dip twice, the second cooling takes about 4 hours in room temp air on a rack.
  18. Zathros

    Zathros Guest

    Air Hardening, definitely a proven method! Quenching first in oil, and letting it cool at a not too fast rate the second time makes for a good edge. Works for drill bits too!
  19. Szdfan

    Szdfan Member

    What kind of oil would you use for this?
  20. Great thread, guys. I'm going to have to experiment with resharpening or hardening X-acto blades. The thought never occurred to me.

    I always knock out my long, straight cuts first with a plain old single-edge razor blade in a box cutter. I've got a huge pack of blades I bought cheap and just change blades/blade ends when needed.


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