[time-nuts] LCD display connector

Chuck Harris cfharris at erols.com
Tue Jan 4 15:23:30 UTC 2011

gary wrote:
> OK. as they say, your mileage may vary. I just buy the real thing. It's
> cheap enough and works great. The price is still $7 for 32 oz at Frys.

99% is about $2-3 for 32 oz at Safeway.  Frys is a surplus house, that is
very regional.  There is no equivalent throughout most of the US.  I have
no idea what they are selling to you as "the real thing".

> I'm not going to clean expensive optics with the drug store stuff. But
> feel free to use the drugstore stuff on your own gear if you want.

If you don't know how to test to see if your cleaner is safe on your optics,
you will have to go with blind faith that the stuff you buy at Frys is
really what you think it is.  I follow the maxim: Trust but verify.

> I have this feeling if I ask the Walgreens pharmacist for the official
> ingredients list of their off the shelf rubbing alcohol I won't get very
> far. But it is an interesting experiment. Or do you mean MDS?

Deflect, and redirect.  Please read over that section of the last post
again.  It should be obvious that you were talking about prescription
drugs when I brought up the pharmacist as a source of information about
prescription drugs.

> I do have some of the junk isopropyl handy. I use for cleaning auto
> parts and the camp stove. It says isopropyl alcohol anhydrous usp not
> less than 99%. No indication what the other 1% is.

Isopropyl alcohol, anhydrous, USP.  USP = United States Pharmacopoeia.
That is one of the many reagent grades.  They don't mention what the
99% is, because it *could* be anything.  In practice, it is water stolen
from the air every time the alcohol comes in contact with the air.

> Regarding denatured, you will find the 70% isopropyl is listed at the
> drug store as denatured. I have none of that in the house so I can't
> produce the label contents. I simply don't buy that stuff.

That is there way of telling you that it is an alcohol, but you can't
drink it.

Look up methyl alcohol, if they are consistent, they will list it the
same way.  Methyl alcohol was the first popular denaturing agent for ethyl

[You possibly weren't aware, but denaturing is done 100% for the tax man.

The tax man is happy to let you have your ethanol free of the sin tax,
as long as some poison is added that will kill or maim you, if you drink

91% and 99% isopropyl alcohol, available from your drug, or grocery, store
is perfectly suited to cleaning electronic assemblies, such as the OP's LCD
display connector.  It is economical, available everywhere, and works very
well.  The more water in it, the less well it works as a solvent, so it is
better to start with the 99% variety.

If you are doing critical chemistry experiments, or something where you
absolutely, positively, must have the purest form known to man, with a
traceable provenance, pay the extra money and buy from a chemical supplier
you trust.

That is overkill for the task of cleaning an LCD display connector.

-Chuck Harris

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