Re: Coating on Toroid

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dave Leddon by way of Terry Fritz <twftesla-at-qwest-dot-net>" <leddon-at-attbi-dot-com>

Ed, et al,

I brought this issue up during a meeting with a bunch of power engineers at
work and one of them said that he'd worked on a project to study this
problem which is, apparently, common in high voltage work.  In the study
they intentionally generated ozone under a fume hood to measure the rate of
corrosion on various components and after two weeks discovered that the
bearings in the hood exhaust blower had corroded to the point of failure.
He further added that any concentration strong enough to cause the kind of
tarnish I've observed (it's not just the toroid now, but all copper and brass
on the coil) in just 15 minutes of operation strongly suggests a need for
additional ventilation, just for health considerations. So in the future,
when 
I run the coil, I'll open the garage door a couple of inches, open the side
door  
and wear a jacket (it's still somewhat cool here in Northern California).

Dave

At 12:07 PM 3/7/02 -0700, you wrote:
>Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
>
>Tesla list wrote:
>> 
>> Original poster: "Malcolm Watts by way of Terry Fritz
><twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
>> 
>> Hi Dave,
>> 
>> On 6 Mar 2002, at 19:46, Tesla list wrote:
>> 
>> > Original poster: "Dave Leddon by way of Terry Fritz <twftesla-at-qwest-dot-net>"
>> <leddon-at-attbi-dot-com>
>> >
>> > Geeks,
>> >
>> > I have now run my coil for a grand total of 15 minutes and have noticed
>> > that the luster has gone out of my toroid.  It seems to be coated with a
>> > translucent haze which comes off easily went wiped with a cloth.  Is
this a
>> > chemical reaction between the aluminum and ozone?  The ozone levels have
>> > been getting pretty high, I had to flee the garage last night when I was
>> > siezed with a prolonged coughing spell after running the coil
continuously
>> > for about 5 minutes.  Anybody else notice this accumulation on their
>toroids?
>> >
>> > Dave
>> 
>> Par for the course I'm afraid. Aluminium is extremely reactive. Most
>> of the time you don't notice as it forms an oxide layer on contact
>> with air which prevents further oxidation. In fact, to paint it with
>> any degree of success, you have to scrape right through the
>> oxidation. This is all the excuse I need for using cooking foil.
>> 
>> Regards,
>> malcolm
>
>	The breakdown voltage of the oxide is low enough that can't imagine it
>affects TC operation in any measurable way.  As for the accumulation of
>stuff on the toroid, I do observe it here and don't attribute it to
>oxidation, but just to precipitation of dust and similar junk.  It will
>wipe off with the hand and probably affects only appearance, not
>performance.
>
>Ed
>