Book Research: Do you think an eyeglass lens would fracture into a usable blade...

Discussion in 'Other Skills' started by YacoltWose, May 13, 2019.

  1. YacoltWose

    YacoltWose Supporter Supporter

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    Hey gang,

    I'm an author and my next series of books will be mysteries in a wilderness setting. I'm enjoying getting my characters into jams and having them figure a way out.

    Do any of y'all know if a pair of modern eyeglass lenses (which are mostly polycarbonate) will fracture in a way to make a usable edge? And by usable in this case, I mean to scrape some shavings off dry wood and maybe fuzz up some small sticks.

    Thanks!

    If anybody is willing to sacrifice a pair of glasses in the name of an experiment, there's a signed first edition in it for you!:dblthumb:
     
  2. marbleman

    marbleman Supporter Supporter

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    Your local Lion's Club has an eyeglass donation box somewhere near you. Find one, grab a pair, and drop in a suitable $$$ donation to substitute.
     
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  3. YacoltWose

    YacoltWose Supporter Supporter

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    Good idea. I'm a 34 mile trip from a grocery store, so there's nothing "local" to me, but if I get an opportunity, I'll try it.
     
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  4. kronin323

    kronin323 the barbarian Supporter

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    Polycarbonate will not fracture like that, no. One of the material's main selling points in sports and safety eyewear is that it won't shatter. Scratch, yes; shatter, no.

    Glass lenses are your best bet for that sort of thing. I don't think they're obsolete enough to be unbelievable.

    You could perhaps sharpen polycarbonate to an edge against a stone, though. I've never tried that. Should be enough to at least make fuzz. I did have a number of junk PC lenses but I chucked them recently. If it's really important to you to test the concept in practice, I might be able to come up with another lens to experiment with.
     
  5. Mr. Tettnanger

    Mr. Tettnanger Supporter Supporter

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    I sell eyeglasses for a living. Modern lenses are made out of several materials.

    CR39/plastic
    Polycarbonate
    Trivex
    High index (1.60, 1.67 mostly)
    Glass (rarely used compared to other materials)

    All can break or shatter. Trivex and polycarbonate are the most impact resistant. They would be the hardest to break.

    The other materials could possibly be broken and be left with useable shards. The effectiveness in doing much scraping and cutting with the small shards would be pretty questionable.

    One needs to ask why sacrifice your eyeglass lenses? Maybe in wilderness emergency or survival situation. But, sacrificing vision may not be the smartest emergency maneuver.

    I can get you a bunch of lenses to try.
     
    Last edited: May 13, 2019
  6. Paulyseggs

    Paulyseggs Supporter Supporter

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    4B7Aay1.jpg i could probably make an axe with these suckers!

    What about pressure flaking the edge?
     
  7. marbleman

    marbleman Supporter Supporter

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    For me, eyeglasses are something I carry a spare of. It would be a necessary survival item for me. I'd have to be pretty down on my luck to be smashing my glasses for anything.
     
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  8. Paulyseggs

    Paulyseggs Supporter Supporter

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    Same here! I carry spare contact lens and glasses. I'm completely disabled without them
     
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  9. YacoltWose

    YacoltWose Supporter Supporter

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    I appreciate that everyone should always be prepared with spare eyeglasses and such, but after being unlawfully detained in the back of a panel truck, freeing yourself from duct tape restraints and getting out of the moving vehicle, one is unlikely to be properly equipped. :11:

    Thanks for the info folks. Good stuff here.
     
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  10. HannahT

    HannahT Firebug Hobbyist Supporter Bushcraft Friend Bushclass I

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    That sounds like a fun read! Are you gonna share with us when you're done?
     
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  11. Jim L.

    Jim L. Guide

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    Glass on the side of the road, maybe? I like the premise.

    Reminds me of a book I once read that had someone use a found shell casing (50 cal.) to make an ulu-like blade.
     
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  12. AdamD1776

    AdamD1776 Scout

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    There are other methods of escaping such restraints, besides cutting your way out. This website has a few a examples: https://www.asgmag.com/survival-ski...e/breaking-free-how-to-get-out-of-restraints/

    *Note: I am not affiliated with this site, and have never tried the methods described. They are posted here purely for entertainment purposes and to provide possible ideas for @YacoltWose 's book
     
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  13. YacoltWose

    YacoltWose Supporter Supporter

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    Our intrepid heroes don't actually use the eyeglasses to escape restraints. They do that using another method I've actually done in training. Thanks to Uncle Sam for the fun times and training...
     
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  14. Paulyseggs

    Paulyseggs Supporter Supporter

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    U have piqued my interest
     
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  15. YacoltWose

    YacoltWose Supporter Supporter

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    I don't want to get in trouble for self-promotion but I will probably put out a call for "beta readers" near the end of the year.

    If you 1) Like to read mysteries, particularly in the CJ Box/Craig Johnson/Paul Doiron/William Kent Kruger vein 2) have a Kindle or similar E-reader and 3) are interested in being a beta-reader, send me a PM and I'll put you on my list. I need a new beta-reader crew for this series because it's radically different than my other work.
     
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  16. MAD Punty

    MAD Punty Supporter Supporter

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    I'm probably not qualified to answer the OP, but....

    If it were me, and I needed to make a blade from a lens, I would try to keep the lens intact and just fletch one edge into a cutting edge. That way, I could have something to hold onto.

    You may or may not find this link useful for your research.

    The Fractography and Crack Patterns of Broken Glass
    https://link.springer.com/article/10.1007/s11668-011-9432-5
     
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  17. TrespassersWilliam

    TrespassersWilliam Supporter Supporter

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    Operation Teardrop: The Hunt for Nazi Germany's Top Secret Ballistic Missile Submarine
     
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  18. Wendy Owens

    Wendy Owens Scout

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    Polycarbonate Fracture? No, but could be abraded on a rock as such.
     
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  19. krflol

    krflol Tracker

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    If the woodlands he finds himself in is as unfortunately trashed by humans as most of the woods I've been in, maybe something like this would be useful?
     
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  20. Mr. Tettnanger

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    Polycarbonate certainly can fracture!
     
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  21. MiddleWolf

    MiddleWolf Guide

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    Glasses of optical quality for reading are available at the local dollar store. My eye surgeon at the Casey clinic told me that was all I needed for simple reading. Sharpen a lens and see. Worked in the eye clinic in the Navy. Never saw a broken lens with any pieces large enough to hold on to.
     
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