Homebrew_PCBs

I did chemistry up to tertiary level and my father was a Canadian
trained chemist...He is now blind in one eye and cannot smell AT ALL due
to constant exposure to these very same type of hi volatility chemicals.
My first job as a 'sales' engineer had me going to Paint companies to
promote filtration. The techs washed their paint smeared hands daily in
a concoction full of aromatic rings..benzene,xylene, toluene; acetone
was always there as well.

After working for a week with them I started to have problems smelling
things properly as well. I left that job.

My fellow hobbyists, you must be aware that frequent exposure to that
volatile stuff WILL penetrate your skin and breathing it in will get it
into your system. Don't compromise your long term wellness for a bit of
convenience. These chemicals are also a serious fire hazard and do not
mix well with nearby mechanical/electrical experiments creating little
sparks when prototyping or metal working. Even the internal arcing from
a Dremel drill can ignite a nearby open acetone bottle or solvent damp
paper towel. It may not happen the first 50 times you do it, but it can
happen anytime and once is enough to take out your lab.

I always wear safety glasses when dremeling, once when cutting off a
6-32 screw the cut piece shot straight into the safety glasses and
ricocheted off before I could even blink. Once in many years, but that
once would have cost me an eye without due care.

Use HP generic toner and one pass hot lamination guys...no fuss, no
muss... no long term risks.

This is how I do it...down to better than 10 mil accuracy.
https://hackaday.io/project/7938-pcb-smt-maker-lab-home


Ancel

On 2/1/2016 9:04 AM, AncelB mosaicmerc@... [Homebrew_PCBs] wrote:

>
> I did chemistry up to tertiary level and my father was a Canadian
> trained chemist...He is now blind in one eye and cannot smell AT ALL due
> to constant exposure to these very same type of hi volatility chemicals.
> <snip>The techs washed their paint smeared hands daily in
> a concoction full of aromatic rings..benzene,xylene, toluene; acetone
> was always there as well.
>
> After working for a week with them I started to have problems smelling
> things properly as well. I left that job.
>
> My fellow hobbyists, you must be aware that frequent exposure to that
> volatile stuff WILL penetrate your skin and breathing it in will get it
> into your system.<snip>
>

Hello--
As a young wiseguy radio/TV repair tech, I asked the shop manager why we
were using methanol to clean
pots and switches instead of carbon tetrachloride, which I had
discovered at the local electronic-supply
wholesaler.

"We used to buy carbon tet by the five-gallon pail", the boss replied,
"And we had one tech who cleaned
everything with it, including washing his hands. Then one day his liver
fell apart and he died. Any questions?"

Long-term chemical exposure isn't the only hazard to consider. Last year
around this time I suffered an
anaphylactic shock reaction to bacteriostatic solution we had been using
in a humidifier. That earned
me an ambulance ride to the hospital and a few miserable days recovering
from a whole-body rash
that itched intensively. I was lucky, because I kept breathing and
didn't totally lose consciousness.

The chemical(s) in question were likely quaternary ammonium compounds
that served as the
bacteriostatic solution. I had no previous symptoms even though we had
used the solution in
previous years.

Along with Ancel's comments, I suggest that you become familiar with the
anaphylactic-shock
phenomenon, just in case you experience a reaction to a chemical or
combination of
chemicals that you encounter in the PC-board process:

http://www.mayoclinic.org/diseases-conditions/anaphylaxis/basics/definition/con-20014324

So now, I pack a couple of EpiPens-- epinephrine injectors that
counteract anaphylactic shock--
when I leave the house. "Concealed Carry" isn't just for handguns!

Be careful Out There.

73--

Brad AA1IP

"'keith printy' keethpr@... [Homebrew_PCBs]"
<Homebrew_PCBs@yahoogroups.com> writes:

> Number one is acetone. A friend once told me it is so volatile if you
> threw a teaspoon of it up into the air it would not hit the ground.

You shouldn't have said that - now I want to try it :-)

If you live on cold & dry enough climate you can do same thing with hot
water. Though some times it comes down as little solid bits.


Cheers,
Will

On 02/02/16 12:14, DJ Delorie dj@... [Homebrew_PCBs] wrote:
>
>
>
> "'keith printy' keethpr@... [Homebrew_PCBs]"
> <Homebrew_PCBs@yahoogroups.com> writes:
>> Number one is acetone. A friend once told me it is so volatile if you
>> threw a teaspoon of it up into the air it would not hit the ground.
>
> You shouldn't have said that - now I want to try it :-)
>
>

The rules for denatured alcohol in the USA are contained in Title 27 Code of Federal Regulations Part 21 (e.g., 27 CFR 21):

https://www.gpo.gov/fdsys/granule/CFR-2012-title27-vol1/CFR-2012-title27-vol1-part21

There are a number of differing formulas.  The one thing they all have in common is that you REALLY don't want to be drinking that stuff.  Furthermore, you probably don't really want to even have it on your skin, since some of the contaminants can go through skin like it wasn't there.  Don't do that. 

As for Acetone, remember that most of us will be dealing with "Technical Grade" materials, as opposed to laboratory grade or USP grade materials.  The difference is that technical grade materials are usually about 95-99 percent pure, while laboratory grade or USP grade are significantly more pure.  The problem is that remaining 1-5 percent in the technical grade may consist of some pretty toxic/carcinogenic materials.  Some manufacturers specify what these contaminants are, while others just list the minimum purity of the desired material.  Read the label! 

As for flammability, there are a variety of factors which can affect this, such as the ambient temperature.  Acetone is usually fairly pure (>95 percent for technical grade), but gasoline contains a whole slew of various straight, branched, and ring hydrocarbons, and predicting the vapour pressure of it is almost impossible, other than by empirically on a case by case basis. 

As a general rule, one wants to stay away from materials containing a Carbon-Chlorine bond (well, ok, so there are a few exceptions, such as solid PVC, etc.).  It's probably not a bad idea to stay away from Cyanide compounds, either (I used to have a really great Tin plating solution recipe, which was based on Sodium Cyanide.  But, knock over a bottle of acid into that plating bath, and if you get one whiff of the gas produced, you'll be dead before you can even hit the floor!).  There are certain other materials which can come out of solution and crystallize into solids which are notoriously explosive.  Silver Nitrate is one of these materials, while other Peroxide based materials are also notorious for this. 

There are probably a bunch of other chemical safety rules that I could/should list, but the basic rules are:  Don't get it on you; Don't eat it; Don't drink it; and Don't inhale it. 

Dave

There is a difference between volatility and flammability. Volatility is a measure of how rapidly the product evaporates; flammability is a measure of how readily it ignites. A very volatile liquid that is very flammable is dangerous (ethyl ether or liquid hydrogen) while a very volatile liquid that is not flammable (e.g. R-134a) is pretty innocuous as far as burn potential is concerned.

Donald.

----- Original Message -----
> From: "'keith printy' keethpr@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Tuesday, February 2, 2016 10:36:09 PM
> Subject: RE: [Homebrew_PCBs] Chemical Exposure.
>
> The underwriters laboratory flammability rating says acetone is more
> flammable. Don’t forget there are other solvents in gasoline especially in
> winter to make it more volatile so you can start your car easier.
>
> Acetone is considered a ketone and some peoples bodies (diabetic) produce it
> when they have problems. You can actually smell it on their breath.
>
>
>
>
>
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Monday, February 01, 2016 11:34 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: RE: [Homebrew_PCBs] Chemical Exposure.
>
>
>
>
>
> The best source for understanding the hazards associated with various
> chemicals is the Material Safety Data Sheet (MSDS) for the material. These
> are based on guidelines and rules established by the Occupational Safety and
> Health Administration (OSHA). You can easily find these by Googling the
> MSDS for the chemical/material that you’re interested in. The MSDS for
> gasoline lists it as a class 1A flammable liquid. The MSDS for Acetone
> lists it as a class 1B flammable liquid. The difference between class 1A
> and class 1B flammability is the boiling temperature or volatility of the
> chemical. See
> https://www.osha.gov/dte/library/flammable_liquids/flammable_liquids.html .
> Materials with a lower boiling point (gasoline) generate more vapors at a
> given temperature than those with a higher boiling point (acetone). Vapors
> mixed with air (oxygen) are what create a highly flammable or explosive
> mixture.
>
> So, per the MSDSs of these two, gasoline is more flammable than acetone.
>
> However, the bottom line is both are highly flammable and you should be very
> careful in handling these.
>
> Mike K5ESS
>
>
>
> MSDS for gasoline
> https://bigcatrescue.org/wp-content/uploads/2014/04/Gasoline.pdf
>
> MSDS for acetone http://physics.utsa.edu/memslab/MSDS/Acetone.pdf
>
>
>
>
>
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Monday, February 01, 2016 4:20 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: RE: [Homebrew_PCBs] Chemical Exposure.
>
>
>
>
>
> We all know how flammable gasoline is , there is a scale rating what is most
> flammable , with 1 being the most and 10 being the least. Gasoline comes in
> at number 6
>
> Number one is acetone. A friend once told me it is so volatile if you threw a
> teaspoon of it up into the air it would not hit the ground. Best to work
> with that one and anything else you may breath outside if you can.
>
>
>
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Monday, February 01, 2016 9:04 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Chemical Exposure.
>
>
>
>
>
> I did chemistry up to tertiary level and my father was a Canadian
> trained chemist...He is now blind in one eye and cannot smell AT ALL due
> to constant exposure to these very same type of hi volatility chemicals.
> My first job as a 'sales' engineer had me going to Paint companies to
> promote filtration. The techs washed their paint smeared hands daily in
> a concoction full of aromatic rings..benzene,xylene, toluene; acetone
> was always there as well.
>
> After working for a week with them I started to have problems smelling
> things properly as well. I left that job.
>
> My fellow hobbyists, you must be aware that frequent exposure to that
> volatile stuff WILL penetrate your skin and breathing it in will get it
> into your system. Don't compromise your long term wellness for a bit of
> convenience. These chemicals are also a serious fire hazard and do not
> mix well with nearby mechanical/electrical experiments creating little
> sparks when prototyping or metal working. Even the internal arcing from
> a Dremel drill can ignite a nearby open acetone bottle or solvent damp
> paper towel. It may not happen the first 50 times you do it, but it can
> happen anytime and once is enough to take out your lab.
>
> I always wear safety glasses when dremeling, once when cutting off a
> 6-32 screw the cut piece shot straight into the safety glasses and
> ricocheted off before I could even blink. Once in many years, but that
> once would have cost me an eye without due care.
>
> Use HP generic toner and one pass hot lamination guys...no fuss, no
> muss... no long term risks.
>
> This is how I do it...down to better than 10 mil accuracy.
> https://hackaday.io/project/7938-pcb-smt-maker-lab-home
>
> Ancel
>
>
>
>

You better not mess around with that, countless people have been badly
injured or killed by water that was too hot, or too cold, or not
enough of, or in an overabundance.

Terrible substance that, exceed the exposure limits and the human body
is no longer able to cope with it.

ST

On Tue, Feb 2, 2016 at 1:38 AM, Will zl1tao@... [Homebrew_PCBs]
<Homebrew_PCBs@yahoogroups.com> wrote:

> If you live on cold & dry enough climate you can do same thing with hot
> water. Though some times it comes down as little solid bits.
>
>
> Cheers,
> Will
>

Yes, very nasty stuff and we all know what fish do in it!

------------------------------------------------------------------------
Stefan Trethan stefan_trethan@... [Homebrew_PCBs] wrote:

> You better not mess around with that, countless people have been badly
> injured or killed by water that was too hot, or too cold, or not
> enough of, or in an overabundance.
>
> Terrible substance that, exceed the exposure limits and the human body
> is no longer able to cope with it.
>
> ST
>
> On Tue, Feb 2, 2016 at 1:38 AM, Will zl1tao@... [Homebrew_PCBs]
> <Homebrew_PCBs@yahoogroups.com> wrote:
>
>> If you live on cold & dry enough climate you can do same thing with hot
>> water. Though some times it comes down as little solid bits.
>>
>>
>> Cheers,
>> Will
>>
>>
>
>
> ------------------------------------
> Posted by: Stefan Trethan <stefan_trethan@...>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
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>
>
>
>
>

Those who are afraid of acetone and denatured alcohol should not be painters, nor should they let their children grow up to be painters. Or, was that song about cowboys?

Ted