Interesting process to remove 'sunburn' from plastic cases

"Fascinating" -- as Spock would say.

Two points... First, the process /is/ patentable. Perhaps he meant that, for
some reason (perhaps other people did most of the work), he and his cohorts
could not patent it.

Second... Since when is hydrogen peroxide a hazardous substance (in the US,
anyway)? When I use mouthwash, I add a bit of peroxide. My mouth is in fine
shape.
 
"hr(bob) hofmann@att.net" wrote in message
news:9908de6f-1c20-4fef-839f-7f800007dd60@po6g2000pbb.googlegroups.com...
On Jan 23, 9:17 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

Second... Since when is hydrogen peroxide a hazardous substance (in the US,
anyway)? When I use mouthwash, I add a bit of peroxide. My mouth is in fine
shape.

Oh, I don't know , sometimes it seems to run off a little bit. <g
Click to expand...
I expected that! ;<)>>>>
 
On Jan 23, 9:17 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:
"Fascinating" -- as Spock would say.

Two points... First, the process /is/ patentable. Perhaps he meant that, for
some reason (perhaps other people did most of the work), he and his cohorts
could not patent it.

Second... Since when is hydrogen peroxide a hazardous substance (in the US,
anyway)? When I use mouthwash, I add a bit of peroxide. My mouth is in fine
shape.
Click to expand...
Oh, I don't know , sometimes it seems to run off a little bit<g>.
 
"Fascinating" -- as Spock would say.

Two points... First, the process /is/ patentable. Perhaps he meant that, for
some reason (perhaps other people did most of the work), he and his cohorts
could not patent it.
Click to expand...
It's possible that that there's enough prior art to prevent this
process from being patented. Hydrogen peroxide has been used as a
bleach for a long time, and the addition of a thickening agent and an
activator such as "Oxy" may not be sufficiently novel to allow for a
useful patent.

Second... Since when is hydrogen peroxide a hazardous substance (in the US,
anyway)? When I use mouthwash, I add a bit of peroxide. My mouth is in fine
shape.
Click to expand...
It's really a matter of concentration.

Household hydrogen peroxide is only a 3% solution (in water). Even at
that concentration, it's strong enough to "burn" the mouth tissues
somewhat if you use it right out of the bottle. I usually dilute it
1:1 with tap water or mouthwash, so the resulting solution is only
1.5% peroxide.

In higher concentrations, hydrogen peroxide can be distinctly
hazardous. It's an oxidizer and (as a result) a bleach, and when
brought into contact with oxidizable materials it can result in a
sudden chemical reaction that releases a lot of heat. And, as noted
in the retr0bright pages, it can cause chemical burns all by itself.
If you splash the 12% stuff around, and get a drop in your eye, you'll
probably be in a world of hurt (literally).

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
William Sommerwerck wrote:
"Fascinating" -- as Spock would say.

Two points... First, the process /is/ patentable. Perhaps he meant that, for
some reason (perhaps other people did most of the work), he and his cohorts
could not patent it.

Second... Since when is hydrogen peroxide a hazardous substance (in the US,
anyway)? When I use mouthwash, I add a bit of peroxide. My mouth is in fine
shape.
Click to expand...


That version is quite watered down. Industrial grade is dangerous.
 
On Wed, 23 Jan 2013 11:24:52 -0800, dplatt@radagast.org (Dave Platt)
wrote:

Household hydrogen peroxide is only a 3% solution (in water). Even at
that concentration, it's strong enough to "burn" the mouth tissues
somewhat if you use it right out of the bottle. I usually dilute it
1:1 with tap water or mouthwash, so the resulting solution is only
1.5% peroxide.

In higher concentrations, hydrogen peroxide can be distinctly
hazardous (...)
Click to expand...
<http://retr0bright.wikispaces.com>
I've used the process to clean up yellowed plastic with good success,
after making the usual screwups. To get the process to work right,
the H2O2 concentration needs to be about 10%. Too little and it takes
forever. Too much concentration and it bleaches the plastic white
instead of beige or whatever the original color. It also bleaches off
any lettering. This might help:
<http://www.h2o2.com/faqs/FaqDetail.aspx?fId=26>

For H2O2, I use 35% "food grade" H2O2. For example:
<http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=35%25+food+grade+hydrogen+peroxide>
Watch out for shipping costs. It requires special handling which can
be expensive. In place of H2O2, I found that commonly available
sodium percarobonate and sodium perborate works fairly well if you
carefully calculate the concentration:
<http://www.textfiles.com/uploads/oxiclean.txt>
It can be found in Oxy-Boost and hardware store wood bleach in powder
form. The typical formulation is:
<http://www.runyoutech.com/htm/FAQ.htm#sodium_perborate_formulations>
Sodium Perborate Monohydrate 45%
TAED 15%
Sodium Carbonate 40%
which provides all the necessary TAED catalyst in one package. Oxi
Magic has the TAED, but the rest is alcohol and lye (sodium hydroxide)
which don't do anything useful for the reaction.
<http://www.clorox.com/products/clorox-oxi-magic/>

As for safety, the ingredients and processes are dangerous and messy.
To get the required UV illumination from the sun, I did my first batch
outside. My deck now looks like a bad case of leprosy due to the
bleach spots from sloppy handling. I also have an old pair of jeans
with matching spots. I always wear safety goggles and nitrile gloves.

I don't plan on doing any more cleanup runs until I can get enough
sunlight for an 8 hr exposure, which means after May 2013. Most of my
HP printers have turned yellow. I'll throw together a web page when
done including my notes on my revised formation.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
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