"mc" wrote in message
. ..
[cleaning flux from PCBs]

I find that metho leaves a white stain on some PCBs.

Get out the meth's again & vigorously scrub the stained areas with an
old toothbrush. That usually does the trick for me.

Isopropyl alchohol is less likely to leave residue, but it costs a lot
more.

Not in the USA. 70% isopropyl alcohol (mixed with water, perfectly good
for defluxing) is 40 cents for 500 mL at the corner pharmacy.

How is isopropyl alcohol made and why is it so cheap and abundant in the
USA compared to other countries?


The IPA normally sold for electronic purposes is very pure at 99.7% or
better. Lower grade rubbing alcohol is also abundant and cheap over here.
However, I have to say that the high grade stuff is not especially
expensive, and lasts a long time. I buy it in a 1 ltr tin, and one of those
lasts about a year in my shop. I don't use it for defluxing though. For
this, I buy an aerosol product from Servisol called "De-Flux 160". It comes
in a 200ml can and lasts me for a good six months. Only a tiny spray is
required, and with a stiff toothbrush, flux and other nasty deposits
disappear like magic.

Arfa