# Keyboard Mylars, second attempt



## rickbb (Mar 21, 2015)

Finally got to finish my second experiment on a batch of Mylars. As before I started with clean Mylars from desktop computers, HP and Acer brand. I did 2 pounds in this batch. I cut the Mylars in half.

Used a 20% by weight NaOH heated to boiling before putting the Mylars in. Took right at any hour for the ink to fully flake off the Mylars. Required vigorous stirring to get the ink to fully flake off as well.

Let the flakes settle overnight to decant and filter the flakes out. After washing and rinsing the ink flakes well I had 12.5 grams of dried ink flakes. Mostly clean but still had some small slivers of Mylar mixed in as did the first batch from some months ago. I put the ink flakes in a small skillet and heated to burn off any wax/ink and Mylar, the now fine dry powder weighted 11 grams.

Melted the dried powder with a very small amount of soda ash and have a 9.8 gram button of clean looking silver after knocking off the small bead of soda ash slag.

This yield is consistent but slightly better than my first go round with 0.31 ozt. from 2 lbs. of keyboard Mylars.

I still think that there should be a better way than with NaOH, I will try a small batch with solvent next.


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## rewalston (Mar 21, 2015)

look forward to hearing more, I've got some mylars waiting.

Rusty


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## solar_plasma (Mar 22, 2015)

Solvents like GBL (known as graffiti cleaner) might dissolve the plastic completely, but since it is a precursor now, almost nobody will have cheap access to it.


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## rickbb (Mar 22, 2015)

I think to dissolve the Mylar would be overkill and leave me with a liquid plastic goo to dispose of. 

I was looking more for something that would dissolve only the ink releasing the silver to settle out. I've tried acetone and it will dissolve the ink, but I have to wipe the Mylar to get it off and then have a paper towel with silver imbedded. Too much labor that way.

I'm going to try some with MEK in a sealed jar and shake it up vigorously to see what happens. Needs to not only break up the ink but break the bond to the Mylar as well. 

If I still had my contacts from when I was in the printing business I'm sure I could get a solvent that would be just the ticket. But after 20+ years, like me, those contacts have moved on to something else.


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## modtheworld44 (Mar 22, 2015)

rickbb said:


> I think to dissolve the Mylar would be overkill and leave me with a liquid plastic goo to dispose of.
> 
> I was looking more for something that would dissolve only the ink releasing the silver to settle out. I've tried acetone and it will dissolve the ink, but I have to wipe the Mylar to get it off and then have a paper towel with silver imbedded. Too much labor that way.
> 
> ...



rickbb

The answer your looking for is H202(hydrogen peroxide) and stirring.Make sure to wear proper safety gear and make sure not to add more than a cap full at a time.Stir it continuously until foaming subsides.My Lye concentration was 6-8 tsp to around 100-150ml distilled water and the Lye was at a simmer before the H202 was added.It stripped the whole mylar that I cut into three pieces,in under a minute.If the first addition doesn't get it all add some more and repeat until complete.Mine was just a small test to see if this would work and it did.If you decide to test this yourself let us know your own results.Thanks in advance.



modtheworld44


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## labworks (Apr 5, 2015)

Just completed a small test. 2 sheets ( cut into 3 parts). it wasn't as quick as 1 minuet, but that really didn't matter. my concentrations may have been off, and it was windy out side, so temp may have been off too. Either way, very cool results, the silver just floated off of the Mylar as you said, I will melt it up tonight and post a weight.

this should keep me busy for a while, and out of trouble! :mrgreen:


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## labworks (Apr 6, 2015)

1st one weighed .5g
todays was 1.0g
it's still cold outside so this is slowing the process. (snow flakes are still in the air.)
I will try a small jar without any heat to see how many days it takes to complete. a set it and forget it, kind of test.


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## rickbb (Apr 7, 2015)

My first go around with this was no heat, I let it sit for 4 days and had zero flaking of the ink. I started adding heat all the way to full boil before I saw any flaking. 

Seems that H2O2 additions are required to get the ink to drop quickly. I haven't had time to try this but hopefully will this weekend along with the solvent removal test I have in mind.

According to DuPont the polyester Mylar will start breaking down in as little as 10% NaOH solution. So the longer you leave it in solution the more polyester flakes you will have mixed in with the ink that will have to be dealt with later. It would save time and trouble if you can get the ink without any Mylar mixed in. (Or just the silver without ink or Mylar would be even better.)


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## mls26cwru (Apr 7, 2015)

this is just a thought, but you said you tried acetone and it dissolved the ink... but you had to wipe it with a towel getting silver in a towel. Did you try disolving the ink and then using an ultrasonic machine? I use that when cemented PM's stick to copper wire and it blows off the crust in 15 seconds... Its just a thought.

M


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## labworks (Apr 13, 2015)

The set it and forget it test. 1 week, no heat and no agitation, the silver was loosening from mylar. ( again very cool to see activity). 
now on my next set it and forget it test.... a 5 gallon pail with a bubbler, no heat. just increasing concentration as i go.
not very scientific. it's been running a few days, no activity, so i added an unmessured amount of lye, and every few days add a little more till i see activity.


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