[Antennas] Cleaning Grungy Aluminum

[John Kemker]

DavidE Benedict wrote:
> CBoone at earthlink.net writes:
>   
>> I did get my bottle of HFL acid at a local plumber supply warehouse (at
>> the
>> time I was working for a public utility and they didn't require any
>> special
>> paperwork from me)...today with EPA, etc you may have a harder time
>> getting
>> it as John Q Public...
>>
>> Chris
>> WB5ITT
>>     
>
> HF is also used extensively in purifying silicon in semiconductor
> manufacturing
>
> BE VERY CAREFUL WITH THIS ACID
>
> Please note that at least high strength HF is extremely dangerous to the
> human (I don't know about various dilutions). 
>
> HF (hydroflouric acid) actively and very vigorously seeks metals, and it
> absorbs through the skin, whereupon it goes to bone (calcium is a "metal")
> and causes EXTREMELY PAINFUL etching of the bone. 
>
> BE VERY VERY CAREFUL WITH THIS ACID
>
> David B.
> W7DBH
> Mobile-Only ...in NW Oregon
>   
Thanks for the warning, David.  When it was suggested, I went to Google
and searched out the MSDS for HF.  What I read made me extremely
respectful of this substance.  As someone who is involved in
experimental rocketry and has made his own motors, I'm very careful with
any chemicals I use.  While I believe the Acti-Brite solution that
Grainger has available is a low concentration, I will be using
elbow-length gloves, a rubberized apron and rubber boots before mixing
in a plastic container.  (It etches GLASS.)  A weak solution will be
used and the runoff will be diluted heavily before disposal.  (My sister
works for the EPA.  Last thing I need is her to send Feds after me!)

--JohnK
73 de W5NNH