Since this is a global distribution, Brian's testimony reminds me of a visit my former manager made overseas. At the board shop, my manager witnessed a vapor degreaser being used, filled with IPA. While it worked fine in "cleaning" the hardware, with over 25 gallons of IPA near boiling, my manager left the premises rather quickly.
BTW - the flash point of IPA is 12C. The flash point of methanol is 11C. With such a low flash point, I would be extremely careful about using either in an ultrasonic cleaner. With a Jet Clean (aka Jacuzzi), yes and I've done that. But with ultrasonics, I would be scared of putting too much energy into the tank, let alone the fumes that it would create.
Along similar lines, at the Indy 500, there was a fire in the pits several years ago. Remember, the CART cars use methanol not gasoline as a fuel, which burns invisibly. They tried using water, but that made the situation worse until they used a fire extinguisher (type unknown but I think it was a halogen).
Lee Whiteman, PMP
Senior Member Engineering Staff
L-3 Communications East
Telephone: (856) 338-3508
FAX: (856) 338-2906
E-Mail: [log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Brian Ellis
Sent: Tuesday, June 30, 2009 11:12 AM
To: [log in to unmask]
Subject: Re: [TN] IPA o r Methanol in Ultrasonic Cleaner
There has been at least one fire in a contamination tester that I know
of for certain. The company in question thereafter decreed that all
flammable solutions and products should be used only in metallic
enclosures because the PVC melted, allowing the burning solution to
spread along the floor, causing considerable collateral damage to the
workshop (I think in millions). I have heard of a possible couple of
other minor cases but nothing that I can quote chapter and verse on.
Remember that the vapours from testers are the IPA/water azeotrope and
not pure IPA. Even the small amount of water, not affecting the flash
point, does reduce the ease with which it burns.
As an ex-manufacturer of contamination testers, we took care in the
design to minimise the risk, although it can never be eliminated. I
emphasise that the one that caused all the damage was not of our
manufacture! :-o
By the same token, the bottle of Laphroaig in the CEO's cocktail cabinet
has an EtOH/water azeotrope over the liquid level, but it has a better
aroma and flavour than the contamination tester solution.
Brian
Richard Kraszewski wrote:
> We have done US cleaning using higher molecular weight alcohols and
> found them to be rather effective, especially in cleaning beneath low
> stand off components.
>
> Using lower weight and lower boiling alcohols like MeOH, EtOH or IPA
> just doesn't work well, so why even take the risk, albeit the risk is
> rather low. Remember that ROSE tester solution (~75% IPA) can get
> rather warm after awhile and I haven't heard about many (any?) fires
> related to that testing operation.
>
>
> Rich Kraszewski
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of John Anselmo
> Sent: Monday, June 29, 2009 10:27 AM
> To: [log in to unmask]
> Subject: [TN] IPA o r Methanol in Ultrasonic Cleaner
>
> Technet,
>
> We are being asked by one of our customers to clean some parts (screws,
> washers, standoffs, feedthrus) in an ultrasonic cleaner with either
> Methanol or IPA (spectroscopic grade).
> The time in the ultrasonics could be up to 1 hour.
> Does anyone else have experience and recommendations for doing this?
> My main concern is safety. What type of room or enclosure do we need
> for this?
>
> Thanks,
> John Anselmo
>
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