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Need some advice on UVC resistant glass.

I've been wanting make my own mercury vapor lamp project for a while (yes I know LEDS exist, this is purely an experiment/fun thing)with a 1000W matchstick sized mv bulb. As far as I can tell this was a water sterilization bulb designed to clean and also be cooled by water. Anyways I was wondering if I run it at a much lower wattage so I don't have to worry about water cooling(100 watts or less), what kind of glass is safe against UVC light:? I have a couple of borosilicate glass tubes, could I just stick it inside one of those? I want this thing to be safe to look at without UVC protective goggles. Is borosilicate good at blocking UVC? Google search turned up mixed results.

Thanks in advance -Ray
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
An outer covering of poly-carbonate should work. http://www.plasticgenius.com/2011/05/infrared-and-ultraviolet-transmission.html

You have to look at transmission curves/

Borosililicate https://en.wikipedia.org/wiki/Borosilicate_glass Transmission in UV

Some experience with UV and Arc lamp sources.

One UV lamp I usedm had a neon sign transformer. The optical output shape was wierd and not constant. You would not expect constant.
-
thanks for that. Do you think I could also coat the polycarbonate in phosphor to make the color glow white or green?
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
probably. https://www.technoglowproducts.com/glow-in-the-dark-paint/ Their paint is UV reactive.

You could consider glass beading the polycarbonate to get the paint to stick or use matt polycarbonate.

You do want the water to see the UV-C light/ http://www.company7.com/library/c7_uv_primer.html

painting polycarbonate - not sure what to expect. if you can find a UV transmittive primer, you might have a better chance, Rough the surface, always helps. glass bead or whatever media is appropriate or sandpaper.

Thick plastics cut well with carbide table saw blade. You might have better luck with thinner stuff running the blade reversed or try a laminate blade.

Painting is an art that I have mastered and surface prep plays a big role.

I've bent acrylic, but not polycarbonate.

I've drilled 5/8" holes in both acrylic by grinding my own bit, similar to a pilot point or bullet bit style. I usually worked with 1/4" thick. 5/8" is a pretty big hole.

The application was a hood/shield where panels were held on with 5/8" wingnuts and held by handles. One panel was about 3' x 8'. We initially used acrylic until we had an explosion. We then changed to polycarbonate.

Dishwashing detergent and a little water in a spray bottle works as a lubricant.

You can fire polish the edges. Edge joining, I personally have no experience with.

I have glass blowing experience (lab stuff, not pretty stuff) too: both quartz and borosilicate. Add welding, soldering and brazing I have most operations covered. I did sealing under vacuum with mosty quartz using a Hydrogen/Oxygen flame. the borosilicate glass propane/oxygen.
 
probably. https://www.technoglowproducts.com/glow-in-the-dark-paint/ Their paint is UV reactive.

You could consider glass beading the polycarbonate to get the paint to stick or use matt polycarbonate.

You do want the water to see the UV-C light/ http://www.company7.com/library/c7_uv_primer.html

painting polycarbonate - not sure what to expect. if you can find a UV transmittive primer, you might have a better chance, Rough the surface, always helps. glass bead or whatever media is appropriate or sandpaper.

Thick plastics cut well with carbide table saw blade. You might have better luck with thinner stuff running the blade reversed or try a laminate blade.

Painting is an art that I have mastered and surface prep plays a big role.

I've bent acrylic, but not polycarbonate.

I've drilled 5/8" holes in both acrylic by grinding my own bit, similar to a pilot point or bullet bit style. I usually worked with 1/4" thick. 5/8" is a pretty big hole.

The application was a hood/shield where panels were held on with 5/8" wingnuts and held by handles. One panel was about 3' x 8'. We initially used acrylic until we had an explosion. We then changed to polycarbonate.

Dishwashing detergent and a little water in a spray bottle works as a lubricant.

You can fire polish the edges. Edge joining, I personally have no experience with.

I have glass blowing experience (lab stuff, not pretty stuff) too: both quartz and borosilicate. Add welding, soldering and brazing I have most operations covered. I did sealing under vacuum with mosty quartz using a Hydrogen/Oxygen flame. the borosilicate glass propane/oxygen.
Doesn't polycarbonate yellow under uv light?
 
I doubt it because it transmits it. We had polycarbonate about 12" away from the stray light of our high intensity source of 254nm (Not UV-C) source with no issues.
I'm trying to block the uv light not transmit it. I basically want to build something that blocks uvc so I can look at it without burning my eyes but it also has to pass visible light sort of like a fluorescent light glass tube.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
I modified my response to "I don't think so" Polycarbonate blocks UV. Acrylic transmits UV.

The florescent tube is excited by UV that strikes the phosfors on the tube., e.g. Mercury vapor. In this case the UV stays inside the tube and the outer glass does not let it escape. The visible light does.

If the florescent paint is toward the light, then the polycarbonate should block the UV the same as a florescent light.

Even without the phosfor, your going to get a blue glow. I used an HVAC UV-C lamp in the shower for mold. Just closed the door and used an extension cord in another room to turn it on. The glow could be seen under the door and even in the ductwork where it's normally installed.

Most plastics don't get along with UV-C. Even nylon cable ties, the black ones can be used outdoors. The white ones cannot.

Migraine today - not thinking as clear as I should.
 
I modified my response to "I don't think so" Polycarbonate blocks UV. Acrylic transmits UV.

The florescent tube is excited by UV that strikes the phosfors on the tube., e.g. Mercury vapor. In this case the UV stays inside the tube and the outer glass does not let it escape. The visible light does.

If the florescent paint is toward the light, then the polycarbonate should block the UV the same as a florescent light.

Even without the phosfor, your going to get a blue glow. I used an HVAC UV-C lamp in the shower for mold. Just closed the door and used an extension cord in another room to turn it on. The glow could be seen under the door and even in the ductwork where it's normally installed.

Most plastics don't get along with UV-C. Even nylon cable ties, the black ones can be used outdoors. The white ones cannot.

Migraine today - not thinking as clear as I should.
So I could put the uvc mercury lamp behind the polycarbonate piece and paint the polycarbonate side facing the uvc lamp so the visible light from the phosphor passes through, without the uvc right?
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
So I could put the uvc mercury lamp behind the polycarbonate piece and paint the polycarbonate side facing the uvc lamp so the visible light from the phosphor passes through, without the uvc right?

I think that could work. Even if the paint chips, your still protected. Painting would be the major issue.
 

Tony Stewart

Well-Known Member
Most Helpful Member
Think of RF filters when choosing optical attenuation. A block is just something that attenuates more than spec. But the range from light emitter to your retina is huge and you have no way of measuring this yet. But it exists if you search to test your material choices. Find what is acceptable for your retina then make a spec.
 

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