Tracey Dobbins on fri 3 jul 98
------------------
Hey Folks:
For the infra-red wizards out here, when does peering into a raku kiln =
become
dangerous without eye protection? Is it just at the high end of the firing
cycle when all glows red? Is it just when looking at flames that happen to
spill over the shelf? The welding goggles, for me, are just too dark to see
squat...and that's all that seem to be available in the supply =
catalogs...rated
at 5, I think.
What's the real scoop on this very important issue? Please beam any =
comments to
the group so we all benefit.
Thanks for everyones time and effort.
Paul Monaghan on sat 4 jul 98
Hi Tracey,
Just to put your mind at ease you don't need welding goggles to peer
into the kiln. Just wear any dark shades which make the viewing
comfortable. The only radiation to be worried about as far as your eyes
are concerned is Ultraviolet which is NOT produced in the kiln. The
Infrared produced in the kiln at kiln temperatures will warm your face
and dry out your eyes if you stand there and hold them open but it
really won't burn them. Use a cheap tinted face shield, tinted goggles,
or tinted sunglasses w/o worry. While you're at it check our website.
Ciao,
Paul Monaghan :-)>
WEB2U Productions
The SECRETS are at
http://www.web2u.com/secret
Tracey Dobbins wrote:
> ----------------------------Original
> message----------------------------
> ------------------
> Hey Folks:
>
> For the infra-red wizards out here, when does peering into a raku kiln
> become
> dangerous without eye protection? Is it just at the high end of the
> firing
> cycle when all glows red? Is it just when looking at flames that
> happen to
> spill over the shelf? The welding goggles, for me, are just too dark
> to see
> squat...and that's all that seem to be available in the supply
> catalogs...rated
> at 5, I think.
>
> What's the real scoop on this very important issue? Please beam any
> comments to
> the group so we all benefit.
>
> Thanks for everyones time and effort.
Paul Lewing on sun 5 jul 98
One other possible result of staring into kilns too long or too close
is that the heat will warp your contact lenses. It happened to my
wife, and they then became unusable. Even clear goggles will prevent
this.
Paul Lewing, Seattle
WardBurner@aol.com on tue 7 jul 98
Hey folks,
Just a few thoughts on this subject and the post below;
<<<are concerned is Ultraviolet which is NOT produced in the kiln. The
Infrared produced in the kiln at kiln temperatures will warm your face
and dry out your eyes if you stand there and hold them open but it
really won't burn them.>>>>
Ultraviolet is produced by the flame (that's why it's so blue, though you
really don't "see the ultraviolet) also refractories can emit UV at very high
temps, but this usually never happens in pottery production.
As far as IR doing no harm.....well the vitrious parts (the gooey insides) of
my eyes are sorta' screwed up and the eye doctor can't tell me for sure that
it wasn't caused by decades of stareing at cones and Raku glazes. IR will
enter the eyes and heat up the interior. Needless to say, I don't look into
kilns anymore without something (like sunglasses) to knock down the IR.
Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com
Paul Monaghan on thu 9 jul 98
Ward my friend,
Taint so! There is a differnce between theoretical physics and the
practical world. The luminous flame has an extremely small UV component
but it is NOT the hazard which was being discussed. The hazard of UV
would only be from an electric arc such as in arc welding. While I CAN
measure UV from a gas flame it is not a hazard and doesn't require
welding goggles also being discussed. The medium and long IR WILL only
cook your eyeballs if you can hold them open long enough. The mid and
long IR WILL NOT pass through plastic or glass and therefore these
materials can be used as shields. Also UV is not what makes the flame
so blue and refractories will reflect UV but they won't produce it. If
you have UV from refractory material the temperatures are SO high that
you will have created a luminous source probably around 6000' Kelvin.
So the bottom line is to just use comfortable tinted glasses and stop
worrying about nonexistant Optical Radiation hazard from a Kiln. Again
if you refer to the archives I did present all the calculations to show
what wavelength radiation is produced at what temperatures, the physical
extent of the source, the radiant power produced, then aperature stop of
the eye and the radiant power focused on the retina for wavelengths
which are transmitted through the aqueous and vitreous humor.
WardBurner@aol.com wrote:
> ----------------------------Original
> message----------------------------
> Hey folks,
>
> Just a few thoughts on this subject and the post below;
>
> <<<> are concerned is Ultraviolet which is NOT produced in the kiln. The
> Infrared produced in the kiln at kiln temperatures will warm your face
>
> and dry out your eyes if you stand there and hold them open but it
> really won't burn them.>>>>
>
> Ultraviolet is produced by the flame (that's why it's so blue, though
> you
> really don't "see the ultraviolet) also refractories can emit UV at
> very high
> temps, but this usually never happens in pottery production.
>
> As far as IR doing no harm.....well the vitrious parts (the gooey
> insides) of
> my eyes are sorta' screwed up and the eye doctor can't tell me for
> sure that
> it wasn't caused by decades of stareing at cones and Raku glazes. IR
> will
> enter the eyes and heat up the interior. Needless to say, I don't look
> into
> kilns anymore without something (like sunglasses) to knock down the
> IR.
>
> Marc Ward
> Ward Burner Systems
> PO Box 333
> Dandridge, TN 37725
> USA
> 423.397.2914 voice
> 423.397.1253 fax
> wardburner@aol.com
WardBurner@aol.com on mon 13 jul 98
Paul,
Been outa' town. I never said UV would hurt your eyes in the amount coming
from burners! I was correcting what you said;
Paul: <<<>>>
It is in small amounts as you followed up in correcting yourself;
Paul: <<<measure UV from a gas flame it is not a hazard and doesn't require
welding goggles also being discussed. >>>>
I never said any of the things you maintain "ain't so" I suggest you reread my
post a little more carefully.....
I said UV emitted by refractories is not encountered in pottery situations
I said IR will heat up you eyes, but the eye doctor couldn't tell if damage
was done by kilns. You, Paul don't know how many hours I have spent staring
into Raku kilns over the past 25 years....
I said anything like sunglasses are adequate to knock down IR.
I'm not going to get into a pissing contest about this. Many folks may have
noticied that I don't post as much as I used to. I have no fear of useful
discussion, but I don't have the time to peck away at the computer trying to
prove my points. I see this go on, not only on this mailing list, but on other
BBS that I read. Many times folks misunderstand or fail to carefully read a
post, then take up bandwidth battleing back and forth over who's right. Again,
I don't have the time away from my customers to do this. I believe we both
said the same thing, although our styles and content are very different. I
wish you a good day....
Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com
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