Homebrew PCBs

There was thread awhile back about using isopropyl alcohol as a board
prep cleaner. The typical stuuf you find is 70%, but you can also get
91%, which is what I buy as a wound disinfectant/cleaner of
contacts...but it still has a significant amount of water.

In the 2006 Allied catalog, there is some very desirable stuff:
99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz (100 ml)
at $4.46, but not bad for 500 ml at $6.53.  So, it's available.

Ted

I don't see why a little water is a problem... usually there's a couple
minutes between cleaning and use for it to dry for me, and doing toner
transfer, i often pre-heat the board with the iron anyway, which should get
rid of any remaining moisture.

-Evan

On 2/18/06, kilocycles <kilocycles@...> wrote:
>
> There was thread awhile back about using isopropyl alcohol as a board
> prep cleaner. The typical stuuf you find is 70%, but you can also get
> 91%, which is what I buy as a wound disinfectant/cleaner of
> contacts...but it still has a significant amount of water.
>
> In the 2006 Allied catalog, there is some very desirable stuff:
> 99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz (100 ml)
> at $4.46, but not bad for 500 ml at $6.53.  So, it's available.
>
> Ted
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
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>
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[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "kilocycles" <kilocycles@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, February 18, 2006 6:50 PM
Subject: [Homebrew_PCBs] Isopropyl Alcohol


> There was thread awhile back about using isopropyl alcohol as a board
> prep cleaner. The typical stuuf you find is 70%, but you can also get
> 91%, which is what I buy as a wound disinfectant/cleaner of
> contacts...but it still has a significant amount of water.
>
> In the 2006 Allied catalog, there is some very desirable stuff:
> 99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz (100 ml)
> at $4.46, but not bad for 500 ml at $6.53.  So, it's available.

The IPA I've got is supplied by Electrolube, and is 99.7%. It's a 1L can, 
and should last me for years. Current price from Rapid Electronics is \ufffd6.99 
+ VAT, which is quite reasonable. It works very well for cleaning resist and 
flux off my PCBs.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller

In article <dt7q8s+6hv3@...>,
   kilocycles <kilocycles@...> wrote:

> In the 2006 Allied catalog, there is some very desirable stuff:
> 99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz (100 ml)
> at $4.46, but not bad for 500 ml at $6.53.  So, it's available.

Hmmm, and the moment you open the bottle it will start absorbing water
from the air - stop worrying about it. Ordinary IPA is perfectly OK

car's gas line antifreezer, is pure isopropyl alcohol.
why don't use it? 

  ----- Original Message ----- 
  From: kilocycles 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Saturday, February 18, 2006 1:50 PM
  Subject: [Homebrew_PCBs] Isopropyl Alcohol


  There was thread awhile back about using isopropyl alcohol as a board
  prep cleaner. The typical stuuf you find is 70%, but you can also get
  91%, which is what I buy as a wound disinfectant/cleaner of
  contacts...but it still has a significant amount of water.

  In the 2006 Allied catalog, there is some very desirable stuff:
  99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz (100 ml)
  at $4.46, but not bad for 500 ml at $6.53.  So, it's available.

  Ted 





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[Non-text portions of this message have been removed]

I've used both and I'll tell you that 30% water makes a big 
difference in the amount of residue left behind.  Many printers 
specify using 98+% IPA and will specifically caution against using 
drug store IPA.  Now I only use 70% IPA for removing sticker residue 
from EPROMs.

Try some of the good stuff and you'll see for yourself.

I buy 98+% IPA at Frys Electronics and hospital pharmacies for about 
$4/pint.

Anhydrous IPA is hygroscopic, so it will absorb water from the air.  
But not nearly as fast as the poster implies.  I put an ounce or two 
in a pump-up dispenser and it's air tight enough for it to keep for 
weeks.  Just don't buy it in gallon containers unless you have a 
vacuum pump to remove air before you close it.  You could probably 
use one of the gadgets they use to pump air out of wine bottles 
after they've been opened.  Any specialty wine store should have 
them...

Regards,
Dennis
--- In Homebrew_PCBs@yahoogroups.com, lists 
<stuart.winsor.lists@...> wrote:
>
> In article <dt7q8s+6hv3@...>,
>    kilocycles <kilocycles@...> wrote:
> 
> > In the 2006 Allied catalog, there is some very desirable stuff:
> > 99.953% pure anhydrous isopropyl alcohol.  Pricey for 3.5 oz 
(100 ml)
> > at $4.46, but not bad for 500 ml at $6.53.  So, it's available.
> 
> Hmmm, and the moment you open the bottle it will start absorbing 
water
> from the air - stop worrying about it. Ordinary IPA is perfectly OK
>

I would be careful of the gas line antifreeze. Since
it going to be burned up, it may be an off spec
version  (to make it cheaper) with other components in
it. These things do happen in manufacturing. That's
one of the reasons I don't eat chocolate ice cream. I
used to make it in a manufacturing plant and know what
goes into it :0 

TANSTAAFL!

Myc





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In article <dt8b4a+30bu@...>,
   dl5012 <dl5012@...> wrote:
> Try some of the good stuff and you'll see for yourself.

Well, I think the availability of chemicals in the US must be rather
different to the UK situation. The local chemists (drugstore to you)
/might/ have meths but not much else.

One independent chemists in my town (long since taken over by a "chain")
used to have HCl but stopped having it due to some change in regulations.

When I refer to "normal" IPA it is what I buy from Farnell or RS
Components, which is sold as a solvent for electronics use. I don't have
the MSDS to hand and it doesn't specify it's "purity" on the tin but it
works fine for me.

What gas line antifreeze might be I have no idea as it would require
exceptionally low temperatures for gas to freeze :^)  In the uk, petrol
doesn't freeze either but suppliers do add ant-waxing agents to diesel
fuel in the winter.

As for Flux removal I use a proprietary product sold by Farnell which is
based on Limonene and relatively safe. It is supplied in an aerosol can
with a stiffish brush on the end to allow scrubbing whilst the stuff is
being applied. It is very effective even on hardened flux residues of
several years vintage (and other crap as well). Certainly much better than
IPA though I usually give a final quick squirt of IPA over the board to
finish.

Sticky label residue from Eproms (or anything else), I find, is best
removed with a proprietary label removal. IPA is very poor at the job.

Regards
Stuart

Stuart,
Actually, the problem the gas line antifreeze solves is water in the
fuel line due to condensation.  It used to be much more of a problem
when carburetors were widely used.  Over her in the colonies, the mix
of the petrol is changed with the season.  In New Jersey, in the 1970s
I had one car that would suddenly stop running each year when the
temperature first dropped below the '30s F.  I had to give it a shot
of fuel additive to get it going.  The alcohol absorbs the moisture
and allows the gasoline to burn.

By the way, I wintered over in Leicestershire during 1982-83.  My car
was a "land crab"...a 1968 Austin 1800 that I rented from my landlord.

Cheers,
Ted

--- In Homebrew_PCBs@yahoogroups.com, lists <stuart.winsor.lists@...>
wrote:

---snip
> works fine for me.
> 
> What gas line antifreeze might be I have no idea as it would require
> exceptionally low temperatures for gas to freeze :^)  In the uk, petrol
> doesn't freeze either but suppliers do add ant-waxing agents to diesel
> fuel in the winter.

---snip---

> Regards
> Stuart
>

In article <dtdlrl+an29@...>,
   kilocycles <kilocycles@...> wrote:
> By the way, I wintered over in Leicestershire during 1982-83.  My car
> was a "land crab"...a 1968 Austin 1800 that I rented from my landlord.

My father had one of those. I used it for a year or so after passing my
driving test, before I got a car of my own. That would have been around
1970. I'm living in Warwickshire, a county that has a border with
Liecestershire.