Query regarding glass surfaces?
Gas Bag
glaziers can fit special non-reflective glass to picture frames. I’ve
felt the surface of this special type of glass, and it is very very
slightly rough. It is perfectly clear and the picture can be seen
perfectly, but there is no glare or reflection visible.
I wanted to know whether or not this special type of non-reflective
glass "fogs up" in warm humid conditions. Perhaps the slightly rough
surface may prevent condensation forming? If a mixture of ultra fine
glass bead powder and clear acrylic lacquer (and lacquer thinners) was
sprayed evenly on a glass surface, this would result in a very fine
rough surface. Could this possibly prevent fogging/condensation on
the surface?
JimboCat
Rough-surfaced glass isn't glare-free: it just distributes the glare
over a larger area, making it less obnoxious. And I doubt it has any
effect at all on condensation. Anti-reflection coatings do a better
job of glare-reduction.
"Fog-free" mirrors are very, very thin and lightweight: the intent is
that they will always be at the same temperature as the air and
therefore moisture won't condense on them. They work so-so.
"Anti-fog" treatments for glass apply a thin, waxy layer to the
surface which is highly hydrophobic (e.g. "rainex"). This works better
if the surface is rough, too (on the right scale). This may be what
you were getting at, but I am not aware of any permanent treatments of
this type.
Jim Deutch (JimboCat)
--
"I meant it kept the rain off the face , which umberallas dont do very
well because mainly the rain in the Northern Hemisphere falls at
greater angles the further north you go" -- Habshi
green
"Gas Bag" <shaz...@yahoo.com.au> wrote in message
news:fa7cec43-f659-4bfb...@c36g2000yqn.googlegroups.com...
There are products out there that do that, google for it.
hint: it is a liquid.
Salmon Egg
<914251c0-b155-4d83...@f30g2000vbf.googlegroups.com>,
JimboCat <10313...@compuserve.com> wrote:
> Rough-surfaced glass isn't glare-free: it just distributes the glare
> over a larger area, making it less obnoxious. And I doubt it has any
> effect at all on condensation. Anti-reflection coatings do a better
> job of glare-reduction.
All I can add is that the use of this glass has the rough surface close
to the picture. If there were a big gap, contrast would be lost. With a
small gap, the scattered light seems to come from where it would be
scattered by the picture surface anyway, It does mean that a picture
with glossy features would be degraded.
Bill
--
Most people go to college to get their missing high school education.
Gas Bag
Thanks for your reply…..and all the others. I’m well aware there are
a whole variety of anti-fog liquids/gels/waxes available. In fact
there’s a particular brand that I use for masks/goggles - it’s
absolutely amazing, and I swear by it. (I’m more than happy to let
you know, but I don’t want to seem like an advertisement for them)
But what I’m trying to do is achieve a permanent effect that is 100%
effective; there already is some technology out there that does
exactly that. Take a look:
http://www.abc.net.au/ra/innovations/stories/s1213247.htm
As fogging on glass/plastic surfaces is caused by water’s surface
tension, I thought perhaps a very slightly rough surface might help
break the surface tension of the tiny water droplets. I’m guessing
probably not, but there’s no harm in asking.
Regards
Gas Bag
Richard J Kinch
> In fact there's a particular brand that I use for masks/goggles
In my day for our scuba masks, we used to make our own that worked quite
well. We called it "spit".
Uncle Al
If it is a hydrated silicate surface you monolayer it with a reactive
silane, RSiX3. -X is typically -OMe or -Cl. R is typically a three
atom spacer then a quaternized ammonium with counterion. That
drastically reduces the surface tension and water sheets not fogs.
Presumably a PEO or poly(vinylpyrrolidinone) oligomer tail would also
the job.
Rain-X takes the opposite tack. Now R is a silicone oligomer and the
treated surface is hyperhydrophobic. Water violently beads but a
breeze blows it off. Very nice for windshields - your wipers glide
across the surface if you need them at all. After treatment, lightly
burnish the surface, wipe with rubbing alcohol, and burnish again.
That gets rid of most of the residual goo.
One wonders why competition swimmers don't "condition" their skin with
hydrophobes. Uncoupling the otherwise wetted surface would
substantially decrease friction.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
Bryce
(snip)
> Rain-X takes the opposite tack. Now R is a silicone oligomer and the
> treated surface is hyperhydrophobic. Water violently beads but a
> breeze blows it off. Very nice for windshields - your wipers glide
> across the surface if you need them at all. After treatment, lightly
> burnish the surface, wipe with rubbing alcohol, and burnish again.
> That gets rid of most of the residual goo.
>
> One wonders why competition swimmers don't "condition" their skin with
> hydrophobes. Uncoupling the otherwise wetted surface would
> substantially decrease friction.
Now that everybody knows, we should expect pre-competition exams by
forensic dermatologists at Olympic swim meets.
charlie
"Bryce" <no...@invalid.invalid> wrote in message
news:h3nnjc$t4q$1...@news.eternal-september.org...
they tried this in the America's Cup sailboat races, along with something
akin to sharkskin riblets, but those ideas were quickly banned.
Charles
I thought so. When I was fooling around in photography I didn't like
the effect of the glare-free glass.
It should be cheap enough to get a readymade frame with some of this
glass and experiment with it.