Isopropyl Alcohol Questions

Discussion in 'Maintenance, Tinkering & Embellishment' started by Chronovore, Oct 19, 2020.

  1. Chronovore

    Chronovore Basic Member Basic Member

    Aug 29, 2019
    I normally use 91% isopropyl alcohol (isopropanol) as a cleaner and degreaser for metal surfaces and knife internals. From routine maintenance to cleaning the factory gunk out of a new budget folder, it's been a marvelously cheap, effective, and "less toxic" solution.

    Aside from metal, it works well on G10 and FRN. G10 can look a little dried out after being cleaned with 91% isopropanol but that is easily remedied by buffing with mineral oil. I've hesitated to use it on wood or Micarta. Does anyone have experience using alcohol to clean Micarta?

    Sadly, the pandemic has made this product much harder to find. Out of frustration, I bought a gallon of 99.9% isopropanol. Does anyone have experience using "pure" isopropyl alcohol for this hobby? I wouldn't imagine a big difference from losing that 9% water but as a wise man once told me: if you don't know, ask.
  2. wade7575


    Apr 3, 2013
    I've used 99% pure and I haven't had any problems with it,I often just use a really good amount of dish soap and work the action of the knife a bunch then rinse it under warm water let it dry or blow it off with air then lube it.
    bigsurbob and Chronovore like this.
  3. MolokaiRider

    MolokaiRider Gold Member Gold Member

    Sep 13, 2017
    I have used paint stripper on Becker’s with micarta. It makes the scales look lighter and clean. It’s pretty tough material.
    bigsurbob and Chronovore like this.
  4. Rhinoknives1

    Rhinoknives1 Gold Member Gold Member

    Jul 1, 2013
    99% Isopropyl works fine as a cleaner .. Just don’t drink it!:D
    David Mary, Chronovore and sodak like this.
  5. The only material I've noticed real troubles with, using isopropyl alcohol (either of 71% or 90+%), is the 'cellidor' plastic handles on the classic-pattern SAK knives from Victorinox. Have to be careful with those, as the alcohol will soften and distort that material. I learned this the hard way, after wiping down the handles on a couple of mine with it. On one of them, the material softened enough that it actually left a perfect embossed thumbprint of mine on the handle. On another, I noticed the handle covers warped after using alcohol, to the extent the recess for the SAK's toothpick wouldn't hold it anymore - it kept falling out.

    I'd also be careful with it on some untreated or unstabilized woods, as alcohol can strip the natural oils out of them pretty fast.
    Ace Rimmer and Chronovore like this.
  6. Blues

    Blues Lapsed SuperMod / Cattle Knife Rustler Staff Member Super Mod

    Oct 2, 1998
    That goes for DEET as well when it comes to SAKs. (I haven't used DEET in years, but it did a number on a SAK I had along with me on a three week backpacking and climbing trip in Alaska. Including the fingerprint, as you mention.)
  7. DEET is mean stuff. I made the mistake of spraying some of that on my socks a couple summers ago, to keep the nasty ankle-biting chiggers or whatever away. The DEET wrecked the elastic in them in nothing flat. I'm afraid to use it for anything anymore, for fear of what it'll ruin next, even if touching something with a little bit of it on my hands. I'm using Picaridin-based products these days for biting bugs. None of the same issues with that, and I haven't looked back.
    MtnHawk1, kreole, mycough and 2 others like this.
  8. Chronovore

    Chronovore Basic Member Basic Member

    Aug 29, 2019
    I've used dish soap and a toothbrush on knives that can't be disassembled. I often find myself finishing with a rinse with concentrated alcohol. Besides drying more quickly, the alcohol seems to pull excess moisture away with it. With Dust-off or compressed air, it's very fast.

    The last couple of times, I just skipped the soap and did a long rinse with alcohol. I put a thumb-tack hole in the top of a seltzer bottle so I can squeeze a light constant stream. Now I can flush a pivot from different angles while gently working the action. Once dry, I can drop some FMO 350-AW into the action, let it sit a second, and then work it in. (Working a totally dry action gives me the willies.)

    NOTE - Always wear safety glasses when squirting or spraying solvent.
    bigsurbob likes this.
  9. Bill DeShivs

    Bill DeShivs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 6, 2000
    Something to think about:
    Using the soap/water/alcohol or just alcohol cleaning method leaves the knife stripped of any corrosion inhibitors. If the knife has carbon steel components, you might want to give it a WD 40 flush afterward.
    bigsurbob and mycough like this.
  10. MtnHawk1

    MtnHawk1 Basic Member Basic Member

    May 22, 2019
    Blues and Obsessed with Edges, do you remember what concentration of DEET damaged your SAK and socks? I'm not surprised if that happened at around 100% concentration but I think most DEET products these days are around 30% or less concentration. Thanks...
  11. David Mary

    David Mary Moderator Moderator Knifemaker / Craftsman / Service Provider

    Jul 23, 2015
    Alcohol is fine for blades, but I find that G10 and micarta around here have never really needed anything beyond soap, water and a toothbrush. Probably not the same one that will go in my mouth, though.
  12. garry3


    Sep 11, 2012
    Why 70 Percent Alcohol Disinfects Better Than 91 Percent, According to a Microbiologist

    "If you’re cutting raw chicken on the counter and want to effectively disinfect the surface to prevent cross-contamination of E. coli and salmonella bacteria, you’d want to opt for 70 percent alcohol. But if you’re trying to disinfect a surface that might have viruses lingering on it—for example, if someone in your house has the flu—any dilution of alcohol will work as long as it’s above the recommended 60 percent."
  13. Chronovore

    Chronovore Basic Member Basic Member

    Aug 29, 2019
    That's a good point, even with stainless steel. However, I don't like WD-40 in this kind of role. The Lubriplate FMO 350-AW I mentioned for dropping into a clean and dry action will protect as well as lubricate. It's pretty easy to work into where you want it. I always wipe down my blade with pharmacy-grade mineral oil after any kind of cleaning. A Q-Tip can be used to lightly coat the inside of the liners in cases where disassembly is not possible.

    I prefer to take a knife apart. Then I can use gun-cleaning patches both for cleaning and lightly oiling. The action, bearing surfaces, etc. get the Lubriplate. All other metal surfaces get the mineral oil. Any G-10 that's been cleaned with alcohol gets lightly dabbed with a small amount of mineral oil and aggressively buffed with a cotton ball.
  14. Craig James

    Craig James

    Oct 30, 2018
    The pure stuff will do the same job as the 70% stuff, but better and obviously more expensive.

    Industrially and from working in a clean room in my past the 99% is preferred particularly for microelectronics as there is minimal water content. It’s main used is obviously as a degreaser and to dewater components due to its fast evaporation and water displacement properties. I’d avoid applying it to wood as stated in some posts above. There is no need and doing so will strip the surface oils.

    There are multiple other industrial applications from the food industry to molecular biology. All use the purest grade.
    mycough likes this.
  15. The DEET I used was one of the very strong formulations, like 98% or so. I'd tried it because I was getting really tired of the ankle-biting bugs that show up every summer here. Had new bites after every foray into the yard outside. For a time, it was a little difficult to find Picaridin products, which I'd used in the past (10-15 years ago) and liked pretty well. After having seen and read how aggressive DEET is on plastics, I put it aside and went shopping again for some of the Picaridin-based stuff, some of which seems to be returning to stores nowadays. That has worked well enough for me to tolerate the bugs.

    I'd personally still worry about using the lower concentration DEET stuff. I wear prescription eyeglasses with coated polycarbonate lenses, AND also hearing aids (plastic-cased). Can't afford to damage that stuff with a bug repellent. So, I don't chance it.
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  16. Blues

    Blues Lapsed SuperMod / Cattle Knife Rustler Staff Member Super Mod

    Oct 2, 1998
    Like David, I always used the highest concentration of DEET available during the years I employed it. Haven't bothered with it for several years now.

    The knife, a Super Tinker, was not harmed in any other way but for the obvious fingerprint and maybe a bit of color fade at the spot. I'm generally pretty good at taking care of my tools, so I wouldn't be surprised that just wiping off the knife and my hands with a bandanna provided sufficient protection to avoid more calamitous results.
    MtnHawk1 likes this.
  17. MtnHawk1

    MtnHawk1 Basic Member Basic Member

    May 22, 2019
    Obsessed with Edges and Blues, thanks very much for the good info! :)

    Good point about polycarbonate lenses. Never thought about that. I always seem to get fingerprints on my glasses no matter how careful I am. I also use Picaridin but with COVID-19 I like to have a Plan B for items I may not be able to buy.
    Obsessed with Edges and Blues like this.
  18. Ben Dover

    Ben Dover Gold Member Gold Member

    Aug 2, 2006
    I use ethanol, methanol and Dawn dish soap all with pretty much satifactory results.
  19. Eversion

    Eversion Making Ti things pretty! Knifemaker / Craftsman / Service Provider Gold Member

    Apr 9, 2020
    I'd try one of those white sponge looking "magic erasers". Works wonders on G10 and micarta, better than alcohol in my experience.
  20. bigsurbob

    bigsurbob Gold Member Gold Member

    Jun 10, 2016
    99% is good to go :thumbsup:

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