Homebrew PCBs

I found a good chemical compatibility table indicating ABS (a common styrene 
based plastic used in electronics) is severely attacked by Methanol, but 
only very slightly attacked by Ethanol.  Methanol is the common denaturing 
agent in the US and this probably explains my experience with denatured 
alcohol attacking styrene based plastics.

I have not had a chance to test some PGA (Everclear) on ABS, but I am now 
assuming I was merely extrapolating my experience with the denatured 
ethanol.  I must have never actually tried the PGA, but simply assumed it 
acted the same way as the denatured stuff.  This also makes me wonder if 
Methanol might actually make a good flux cleaner since I have had a nagging 
suspicion that the denatured alcohol actually works a bit better as a flux 
cleaner than the PGA.  But not really sure about that observation.

As to the denaturing agent being Methyl Ethyl Ketone (MEK) in Europe, that 
is rather interesting.  MEK is VERY aggressive against ABS and PVC.  It 
would be hard to believe that Ethanol denatured with MEK would not be as bad 
as Ethanol denatured with Methanol with respect to attacking ABS.

Syd H. Levine
AnaLog Services, Inc.
Phone:  (270) 276-5671
Telefax:  (270) 276-5588
E-mail:  analog@...
Web URL:  www.logwell.com

----- Original Message ----- 
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, November 28, 2006 8:17 PM
Subject: Re: [Homebrew_PCBs] Isopropyl Alcohol 90%


> On Wed, 29 Nov 2006 01:14:48 +0100, Peter Harrison
> <peter.harrison@...> wrote:
>
>> I would suggest you may both be right. I was curious about this so I
>> popped down to the garage and tried some polystyrene foam in both IPA
>> and denatured ethanol. Neither had any noticeable effect upon the
>> polystyrene foam. This is perfectly reasonable. Imagine a world where it
>> was not possible to go to those classy parties where you get to drink
>> beer and wine from polystyrene cups for fear that they dissolve in your
>> hands.
>
>
> How could both be right? Either is is attacked significantly or it isn't.
> I can't see no effect of ethanol on styrene and i'm tired of hearing those
> claims without any proof.
>
> ST
>
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