Coffee Stains

[milandro]

Originally Posted by mrwizard

Since I'm notorious for leaving coffee stains everywhere, i felt challenged when i read on a knife-makers forum that coffee gives good contrast on damascus.
So, i selected a Bali tourist/soldier keris, i couldn't successfully stain with FeCl3, and made a lot of coffee....

First i followed the instruction given on the other forum and prepared the coffee with two spoons of instant-coffee per 200mL of hot water. Meanwhile the keris is degreased and etched for 2-5min in citric acid. The keris is then fully submerged in the still hot coffee. The pamor became visible after 2h and reached its maximum contrast after 6h. The result was rather disappointing. After drying the pamor was barely visible.

Next i repeated the procedure with "real" and strong coffee. That lead to the same result after 2-3h.

For the final experiment i added a teaspoon of citric acid to the coffee (about 4L). This gave a remarkably good result after about an hour (see photo). Leaving the keris longer in the coffee proved counterproductive as the contrast began to degrade after the coffee cooled down.

After the promising results i tried to stain the keris from this thread http://www.vikingsword.com/vb/showthread.php?t=13829
with the same mixture. However, this time the result was very poor.

Conclusion: Coffee may for some keris be a viable alternative to FeCl3 but may fail miserably on others.
For good results the coffee has to be hot and slightly acidic.

Best Regards,
Thilo

when I got my first kris I tried the coffee method and results were actually quite good , later on I did have this kris etched with traditional warangan and the results were better but not spectacularly better.

Then I tried the same thing on two KNIL soldiers krises made in Madura , coffee did absolutely NOTHING there just literally a stain which could be washed off with water.

[Battara]

Any pictures?

[milandro]

unfortunately not , I've kept a couple for a while of this experiment on my phone but then I erased them at some point.

I guess that it depens on the metals involved.

Perhaps one of the so many videos on your tube would inspire someone

https://www.youtube.com/watch?v=inGtEynlP0E&t=1215s

It clearly is not one easy thing

[A. G. Maisey]

Absolutely first class.

Thank you Milandro.

[kronckew]

Apparently Instant coffee is more acidic than fresh ground coffee.

[milandro]

this is , of course, very difficult to determine.

Apparently Instant coffe and normal coffe MAY have the same acidity

https://theoldcoffeepot.com/is-insta...e-less-acidic/

however there is enormous variation and of course what works under certain conditions may be completely not apt to do the job in another.

I have heard on several videos that people prefer the cheapest possible brand of instant coffe, so the first time I used good instant ( and it worked) while the second time I used Cheap instant ( and it didn’t).

[David]

Thanks for that video Milandro!