Homebrew PCBs

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
> 
> 
> 
>