"Cokerizing"

[Kaizer]

Hello freinds,

It's been a long time since i was off this forum. Had truck loads of work.



Anyway, at rec.knives in the google forum there is a thread that talks about something called "Cokerizing" your knife. first a bit of background...

Just as some guns are parkerized or "blued" (forgive me, i do not know why, neither do i know how they do that) it was suggested that a blade be left in a cup full of coke overnight. The next morning (basically, around 12 hours later), the blade will be *colored* differently (a kind of mocha - chocolate type) due to the phosphorous in the coke reacting with the metal. Have any of you tried this exercise? Is there someone who can share there experiences on this topic?

Apparently, it is not a one time process. you have to follow a regime of cokerizing the balde every day for around a week till one gets the desired effect. also, in some cases the color could get wiped off / scraped off...in which case one needs to start all over again.



I do not know the chemistry of it all but i can bet that it would ultimately ruin the blade coz of the phosphorus eating in to the metal. pitting, maybe even that dreaded 4 letter word RUST!!



Let me hasten to add that i would not be responsible for any discolored spydies!!! If any of you are the adventurous kind may i suggest that you use some old kitchen knives first to see the effect. Anyway, i am certain that all you forumites in your right minds and wont try this kinda stuff on the &quot;real thing&quot; (a.k.a. <img src="spyder.gif" width=15 height=15 align=middle border=0>) before extensive tests on some broken down thing.

I for one have not been able to replicate the results on a standard kitchen knife here. so i was wondering am i doing something wrong or is cokerizing just a figment of one's imagination.



Kaizer.



P.S. Just wondering...If coke does this to metal what on God's earth would be happening to our insides? <img src="sad.gif" width=15 height=15 align=middle border=0>



Have a nice day.

[dialex]

Interesting. Anyway, it won't work in my case (I just couldn't stand to see that glass of coke and not to drink it<img src="smile.gif" width=15 height=15 align=middle border=0>)

[java]

Kaizer,

Read somewhere before where Coke was used to remove rust off of car bumpers. Has something to do with the chemical reaction of the phosphoric acid (H3PO4) that they have in there. Kind of a an acid etch or planarization as we call it in the semiconductor business, where the surface layer is stripped clean for processing. Coke has a pH of approximately 2.5 - 2.7, not a particularly strong acid but it can do a little etching. Over time, I don't think I would worry about rust - I'd worry about pitting the blade and eventually weakening it! The brown colorization is probably due to other impurities in the Coke being deposited in micro-pitted areas and will more than likely wear off or wear unevenly over time – not a pretty prospect.

Acid, in particular Aqua Regia (a mixture of hydrochloric and nitric acids) is used to etch the beautiful patterns seen on some blades, but learning this process takes time, a good supply of blade stock, and the chemicals and process must be constantly monitored. Although the H3P04 in Coke is relatively weak and this claim of “Cokerization” may help somehow in the battle between Coke v Pepsi, this is definitely something best left in the realm of the curious and interesting things to do with a glass of Coke when you’re bored on a Saturday night but not something you would want to try on a good blade even if I you think you’ve got the procedure down. This process sounds dubious at best, mein Kaizer. But, I could be totally wrong.

For real “Better living through Chemistry”, try searching some of the tutorials found at Custom Knives http://www.customknifedirectory.com or those at http://64.176.180.203/tutorials.htm or read David Boye’s Step-by-Step Knifemaking. Chapter 19 details the etch process for blade steel. For other entertaining uses of Coke try this URL: http://community-2.webtv.net/krokai/SURPRISINGCOCACOLA/

Interesting post though! <img src="smile.gif" width=15 height=15 align=middle border=0>


Stay safe! Stay sharp! &lt;img src=&quot;spyder.gif&quot; width=15 height=15 align=middle border=0&gt;

Edited by - Java on 6/11/2002 3:36:53 PM

Edited by - java on 6/11/2002 3:59:02 PM

Edited by - java on 6/11/2002 4:00:59 PM

[delicrazy]

i tried it with diet pepsi twist. didnt make my kershaw change colors but it made my blade really really clean. think i just found a new cleaning method

[Knife Knut]

ok, i cant figure out how someone would come accross this oddball technique