Are spray cleaners fire hazards ?

[Phil Allison]

Hi to all,


A poster on a US guitar amp newsgroup managed to set his amp on fire using
a contact cleaner spray. Apparently he used a fair amount of the stuff down
each jack socket hole then operated the AC switch - it went "woooof " and
he had a raging fire inside.

Most contact cleaners contain alcohol as a solvent, possibly isopropyl,
this has a low flash point of 11 degrees C. The cans all have a red badge
with "flammable liquid 3" - which seems to be code for ***major fire
hazard**.

A can of the humble WD40 has the same red badge with "flammable gas 2" -
which is a bit mysterious since the propellant is CO2. The flash point of
WD40 is much higher at 55 degrees C, according to an official chemical
hazard data sheet on the web. Far as I can tell, unlike alcohol, its fumes
are not prone to igniting from a spark unless the liquid is heated
considerably first.

Seems like a dam good reason to stay away from the expensive evaporative
cleaners in favour of WD40.




............... Phil

 

[Rob]

Hi to all,


A poster on a US guitar amp newsgroup managed to set his amp on fire using
a contact cleaner spray. Apparently he used a fair amount of the stuff down
each jack socket hole then operated the AC switch - it went "woooof " and
he had a raging fire inside.

Most contact cleaners contain alcohol as a solvent, possibly isopropyl,
this has a low flash point of 11 degrees C. The cans all have a red badge
with "flammable liquid 3" - which seems to be code for ***major fire
hazard**.

A can of the humble WD40 has the same red badge with "flammable gas 2" -
which is a bit mysterious since the propellant is CO2. The flash point of
WD40 is much higher at 55 degrees C, according to an official chemical
hazard data sheet on the web. Far as I can tell, unlike alcohol, its fumes
are not prone to igniting from a spark unless the liquid is heated
considerably first.

Seems like a dam good reason to stay away from the expensive evaporative
cleaners in favour of WD40.




.............. Phil

I raised this question where I work. Aerosol packs of Iso-Propyl with VPI
(vapor phase inhibitors - anticorrosion) are used for defluxing boards in a
production environment full of heat guns and live (mainly DC) gear. It does
wonders for your skin and leaves a nice white deposit of acid salts on the
boards unless fairly vigorous scrubbing is used when cleaning.

Apparently flammability is not a problem as "we have done it this way for
some time and not had any problems". :~}

How is flashpoint determined ? If it is not determined / measured in the
atomised state then is flashpoint relevant to 'flammability risk' ?

rob

 

[Phil Allison]

"Phil Allison" <[email protected]> wrote in message

How is flashpoint determined ? If it is not determined / measured in the
atomised state then is flashpoint relevant to 'flammability risk' ?

** A small container of the liquid is held at a controlled temp and a flame
is introduced into the air above it. The temp at which the liquid first
produces enough vapour to catch alight is called the flash point. If the
container is closed then the temp is few degrees lower than if it is open.

Do a Google on "flash point" for more info.



............ Phil