Cleaning RK05 packs (Was: LGP-30 Memory Drum Update)

[Paul Koning]

> On Jan 5, 2017, at 8:55 AM, Pete Turnbull <pete at dunnington.plus.com> wrote:
> 
> On 05/01/2017 13:22, Noel Chiappa wrote:
>>    > From: Klemens Krause
>> 
>>    > We clean our RK05 disks in a very robust way: with cheap burning spirit
>>    > and paper towels. ... We rubbed away thick black traces from occasional
>>    > head crashes and we never removed the oxide coating with this torture.
> 
>> First, what is 'burning spirit'? (I assume this is a straight translation
>> into English of some German term, but not knowing German... :-) After poking
>> around with Google for a while (hampered no little by the fact that it's the
>> name of a band, and also a term in World of Warcraft :-), it seems like it
>> might be acetone?
> 
> I'm sure it's not ! :-)  He'll mean the sort of alcohol used in a spirit burner.  The UK equivalent is "methylated spirit" - primarily ethanol but with a (un)healthy dose of methanol to make it unfit to drink (and hence exempt from excise duty) plus pyridine (and small amounts of other things) to give it an unpleasant taste and odour, and some methyl purple dye to make it obvious at a glance.  Denatured alcohol, in other words. I don't think the German (EU) version has the dye although it does contain IPA and MEK.  For cleaning, because of that dye, isopropyl alcohol (IPA, isopropanol) is often a better choice in the UK.
> 
> In the US, "rubbing alcohol" is mostly denatured ethanol (though "isopropyl rubbing alcohol" is mostly IPA), but always contains other chemicals as well.  Either should do for cleaning a disk.

I recognized "burning spirit" by its Dutch analog, and yes, it means denatured ethanol.

I would suggest avoiding these blends of random chemicals made with no real concern for purity.  You need a liquid here that will evaporate cleanly, leaving behind neither oily residue nor solids.  I see no reason to believe that denatured alcohol or rubbing alcohol are made to those standards.

	paul