Jean, Rudy,
If you are going to use ammonium bifluoride (ammonium hydrogen fluoride for
the non-chemically inclined), BE CAREFUL. All ionic fluorides should be
treated with care. Certainly this one is not as bad as hydrofluoric acid,
fluorosulfuric acid or super oxidizers like arsenic pentafluoride, but do be
careful. I could go on about other very interesting nasties, but I'll
control myself and stop here. Fluoride burns are nasty. They don't always
hurt at first, but they sure will later! Fluoride will continue to
penetrate the skin and will eventually start to leach calcium from the bones
and can lead to localized "chemical osteoporosis" (my term, I'm not a med).
It would be a good idea to have at hand as a first aid treatment a saturated
solution of tetramethylammonium chloride or some other quarternary ammonium
salt. If one comes in contact with a solution capable of liberating
fluoride, dip the affected portion in an ice cold saturated solution of this
stuff (good chemical term). The tetramethyl ammonium ion will sequester the
fluoride ions enough to let the body deal with them. The cold decreases the
diffusion rate of the fluoride into the depths of the body. Certainly the
ice will dilute the stored room temperature saturated solution, but that's
OK. Obviously remove the affected portion form the cold solution once in a
while to avoid excessive cooling and its attendant problems.
I'm not making this up. Check it out in the CRC Handbook of Laboratory
Safety, 2nd Edition, CRC Press Inc., Boca Raton, 1976, pp45-47 (obviously
different pages in newer editions! :) ) This is based on some excellent
work by a med in DuPont, who know full well about fluoride burns from past
experiences, unfortunately.
regards,
Bev Christian
Nortel
> ----------
> From: RSedlak[SMTP:[log in to unmask]]
> Sent: Thursday, May 14, 1998 10:45 PM
> To: [log in to unmask]
> Subject: Re: [TN] Help
>
> Jean:
>
> This is one of those experiences that may be exactly what you need, or may
> also result in gales of laughter.
>
> I had a similar need, to glue my rear view mirror to my windshield, in a
> non-
> standard position. I solved the problem by using standard Dow RTV
> silicone,
> BUT, in order to get it to adhere, I had to roughen the surface of the
> glass,
> using emery paper.
>
> Now, using emery paper on your parts may be difficult, or impractical, and
> so
> my suggestion is use a mild glass etch, which could be a simple 10%
> solution
> of ammonium biflouride, which you could put on with a cotton swab. Rinse
> well, then dry, and apply your silicone.
>
> Hope it works for you.
>
> Rudy Sedlak
> RD Chemical Company
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe: SUBSCRIBE TechNet <your full name>
> To unsubscribe: SIGNOFF TechNet
> ################################################################
> Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional
> information.
> For the technical support contact Dmitriy Sklyar at [log in to unmask] or
> 847-509-9700 ext.311
> ################################################################
>
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################
|
