A quick guide for Black lights (UV light).

[TAGster 5]

Hello Mates,

 

Recently I am very fascinated (maybe obssesed) with the lume on the watches, and I am willing to re-lume some of my pieces, so, because of that I´ve been doing some "homework" and I found this two interesting articles from Glowinc that talks about the "best" way to charge fluoresenct stuff including a very complete explanation of how the different UV lights (black light) works.

 

Maybe some of you had already read it, but I think is a interesting articles to share in the board:

 

Article 1.

 

Choosing a bulb to charge your glow in the dark items

The brightness and type of bulb determines the efficiency at which phosphorescent material charges. Efficient bulbs not only charge faster, but can obtain a brighter level of glow.

 

A black light shining on a glow surface for 30 seconds will cause that surface to be 10 times brighter than a flashlight on it for 6 hours.

 

Here is a simple list of bulbs in order from least to most efficient:

 

White LED's

Blue/Purple LED's

Incandescent - standard light bulb

Compact Fluorescent or CFL - spiral tube, screw-in

Fluorescent Bulbs - long tubes

UV LED's

Black Light Tube

Direct Sunlight

 

The efficiency of light as a phosphorescent charging source is determined by its brightness and its spectrum. White light is comprised of equal amounts of all of the colors, such as red, green, and blue. White light bulbs typically also emit ultraviolet (UV) light, which is the "color" above purple in the spectrum, which humans can not see.

 

Each part of the spectrum effects glow in the dark materials differently.

 

Red light actually discharges the glow pigments.

Green light is neutral.

Blue Light inefficiently charges the pigments.

Ultraviolet light charges the pigments efficiently.

 

A standard incandescent light bulb emits similar amounts of the four colors above. The green does not effect the glow pigments. The red discharges and the blue charges in similar amounts, which results in a cancelation. The result is that only the ultraviolet is working to charge the phosphorescent pigments.

 

Therefore, when using a 100 watt incandescent light bulb as a charging source, only about 10-25 watts are working to actually charge the pigment. Therefore, a 60 watt black light bulb will far outperform the higher powered white light.

 

The efficiency of white light can be determined by the ratios of the colors contained. "Warm" lights contain more red and therefore are poor for charging glow in the dark items. "Cool" or "Daylight" bulbs contain more blue and therefore are slightly more efficient. Fluorescent bulbs, both CFL and tube style, naturally emit more ultraviolet light, which makes them more efficient.

 

Black lights have another major advantage. White light bulbs cause the human eye to adjust to the bright light. When the light is removed, it takes 15 minutes for human eyes to adjust back to the darkness. If your eyes are adjusted for a bright room, then even the brightest phosphorescent material will appear dim when the light is removed.

 

Black lights do not cause your eyes to readjust. For most applications, this will cause the glow in the dark materials to "appear" considerably brighter.

 

The final major consideration is direct vs. reflected light. Many ceiling fixtures are designed to point light down onto a room. Therefore, the only light reaching the glow in the dark stars on your ceiling is reflected. Reflected light is extremely inefficient for charging.

 

This holds true for sunlight entering through a window. While a room inside may look bright, it is mostly from reflected light. This is also why glow in the dark house numbers on a west-facing house are brighter at 10pm than an east-facing house.

 

A frequently asked question at Glow Inc. is "How long does it take to get a full charge" The easy answer is that any of our products will be at their maximum charge from any light source in 20 minutes. However, that is a useless answer.

 

"Maximum Charge" will change depending on the light source. A black light on for seconds can cause our products to glow brighter than an incandescent bulb lit for 10 hours. Of course, the speed of charge is also determined by the light source.

 

A "full charge" is also a hard statement. Under black light, most pigments will get to 80% of their charge within seconds, 90% over 30 seconds, 95% over about 2 minutes, 100% in about 10 minutes.

 

This is further complicated by the size of the pigment. Larger pigments can glow brighter and longer, but charge slower.

 

In conclusion, use a black light if possible. If white light is needed use CFL "Daylight" bulbs.

A request from the author:

 

Glow Inc. has always been at the forefront of providing free technical information on the subject of "glow in the dark". Most recently, we added the Glow in the Dark Forum so that customers can add to this free information base.

 

However, we are in desperate need of exposure on the Internet. If you enjoyed this article, please consider putting a link to it on your website, blog, or your favorite forum.

 

 

 

 

Article 2.

 

"Black Lights

 

Anyone seriously using phosphorescent or fluorescent paint will also need to understand black lights and the long wave ultraviolet light they emit. Black lights are by far the most efficient way to charge glow in the dark paint and it is mandatory for fluorescent paint.

 

Unfortunately, manufacturers use the words “Black Light” and “UV” carelessly and confusion follows. This problem has increased recently with the advent of falsely labeled UV LED’s. This article will define black light, discuss various bulbs, and give you the tools to choose an efficient black light for your project.

 

 

450–400 nm

Spectrum

 

The colors we see are determined by the wavelength of light energy. Unlike some insects, humans can only view the spectrum from red to violet. However, other invisible “colors” exist above and below this spectrum. The “color” above red is called infra-red and the color below violet is called ultraviolet. ultraviolet light will cause fluorescent or phosphorescent pigments to fluoresce, emitting visible light.

 

The ultraviolet spectrum is broken down into subcategories depending on wavelength:

 

450 - 400 nm Violet, (visible light, shown for reference)

400 - 320 nm UVA, Long Wave, Black Light

320 - 280 nm UVB, Medium Wave

280 - 100 nm Short Wave, Germicidal

 

Long wave ultraviolet (UVA) used for true black lights is relatively safe on the eyes. Medium and short wave ultraviolet light can do damage to eyes. For legal reasons, I will refer you to other sources for the safety of using various UV products.

 

Therefore, an ideal black light has the shortest wavelength possible without going below the dangerous 320 nm threshold and has nominal visible light (above 400 nm). Traditional black lights emit an average wavelength of 365 nm and have a filter (often ordinary glass) to eliminate anything below 320 nm.

 

Filters

 

Ordinary glass filters medium and short wave ultraviolet light, while passing visible and long wave ultraviolet light. Our Earth’s atmosphere filters short wave ultraviolet light.

 

A special type of glass called Woods Glass filters visible light along with medium and short wave ultraviolet light. Due to its high cost, it is only used in very high-end black lights. Most black lights use a coating with similar properties.

 

Black Light Blue SpectrumBlack Light vs. Black Light Blue

 

 

Terms for black light bulbs are a bit different than for the fixtures. Black light fixtures contain a bulb called a "Black Light Blue" or BLB bulb. This bulb uses cobalt blue glass and emits very little purple visible light in addition to the long wave ultraviolet light.

 

There are also "Black Light" or BL bulbs. These bulbs are made of a clear glass and emit a relatively large amount of blue visible light along with the long wave ultraviolet light. BL bulbs are often used in bug catchers.

 

BL bulbs emit more long wave UV than BLB bulbs. However, it is hard to see objects fluoresce due to the large volume of visible light. In addition, BL bulbs will cause your "night vision" to readjust to the bright light. The result is that when you turn a BL light off, your glow in the dark items will appear to glow less.

 

When most people refer to black light, they really mean black light blue. For this article, outside of this section, we will use the common term "black light" to refer to black light blue as well.

 

Tron Arcade Game - Black LightFor a bit of trivia, the famous Tron arcade game in the 1980’s included both a traditional BL and a BLB bulb. Since most of these machines have been repaired by technicians that do not understand BL bulbs, it is rare to see a Tron game that looks as it was intended. A prized possession of the Glow Inc. staff is a properly restored Tron game.

 

Interesting Facts

 

Black light does not affect or alter your “night vision”. In addition to its efficiency, this makes it the ideal charging spectrum for glow in the dark items.

 

High powered, long wave ultraviolet light can often penetrate clothing and illuminate white underwear causing embarrassing situations. This is due to phosphors added to white clothing dye to make them look whiter in sunlight.

 

 

Reflection

 

Long wave ultraviolet light does reflect efficiently off of mirrored surfaces. Like visible light, it retains 80-90% of its brightness with a good mirror. Most polished metal surfaces and cheap plastic mirrors only reflect 60-70%.

 

Medium and Short wave ultraviolet will not reflect in a mirror due to passing through the glass.

 

Fixtures

 

When choosing a fixture, keep in mind size, durability, portability, power requirements, weight, and heat output. Also, choose a fixture with a reflector, preferably a glass mirror.

 

Ultraviolet Light Sources

 

The sun and almost all types of white light bulbs emit some long wave ultraviolet light. That is why the sun and most light bulbs can charge phosphorescent paint. However, this article is going to focus on bulbs, known as black lights, that are designed to primarily emit long wave ultraviolet light.

 

Black Light LED PanelLED

 

The wavelength of light emitted from an LED is very specific. When you buy an LED, you can specify exactly what wavelength you wish it to emit. Ideally, for black lights, you would use 365 nm LED’s.

 

Therefore, you would assume that manufacturers of black light products would stick to that wavelength. Why do they not do that?

 

A 365 nm LED is only about 20% efficient as a 405 nm LED. Individual 365 nm LED's are also relatively expensive. Therefore, manufacturers need a massive number of expensive LEDs to create a decent LED Blacklight.

 

Furthermore, light from true 365 nm LED’s is not visible and therefore uneducated consumers are not happy with the "light output".

 

The popular stage lighting company, Chauvet, released a “black light” consisting of 192 “UV” LEDs. This product is a great VIOLET light using 405 nm, visible light, violet LED’s. However, it is almost completely useless as a black light. You can understand their reasoning when several DJ’s reviewed this light as “much brighter” than more powerful fixtures emitting true long wave ultraviolet light. The reviewers were making this determination by how much light they could see. Properly, they should have used fluorescent paint to determine the best fixture.

 

Flashlight manufacturer Inova, makes a “UV” flashlight with 3 365 nm LED’s and 2 405 nm LED’s for the same reason.

 

LED’s use relatively low electricity and emit almost no heat . They turn on instantly and can be very bright. They also have an extremely long bulb life.

 

If you select an LED fixture, you just need to make sure that the product you are buying includes 365 nm LED’s.

 

Currently, LED fixtures of similar power are 10-20 times more expensive then standard fluorescent black lights.

 

Incandescent Black Light BulbIncandescent Bulbs

 

Incandescent black lights are created by taking a regular white light bulb and adding a coating to filter the visible light, passing only long wave UV light.

 

Since less than 2% of the light is emitted as long wave UV, they are very poor black lights. As such, you would think they would not ever be sold.

 

Incandescent bulbs are popular because they are cheap and can screw into any home fixture. Unfortunately, they are useless for charging glow in the dark items. In fact, they are almost completely useless unless you want a violet light bulb.

 

Fluorescent

 

Fluorescent Black Light TubeBlack light and white light fluorescent tubes are very similar.

 

The mercury inside of all fluorescent tubes primarily emits UV light (long, medium and short).

 

For white lights, the inside of the tube is coated with fluorescent phosphors to convert UV light to visible white light. The glass of the tube filters any remaining medium and short wave UV.

 

The phosphors in a black light fluorescent tube convert all of the UV light to long wave UV. For most black lights, a coating on the exterior filters any excess visible light (above 400 nm). The result is an extremely efficient, inexpensive black light.

 

Fluorescent tubes vary by both length and thickness. Popular black light thicknesses are T-8 (1”) and T-12 (1.5”). Contrary to instinct, T-8 bulbs, using newer technology, are brighter, more efficient, flicker less, and can start in colder temperatures. Therefore, there is no reason to buy a T-12 bulb or fixture. Of course spectrum, brightness and quality vary by brand.

 

The only problem with full size fluorescent tubes as black lights is that they are large and delicate.

 

CFL Black LightCompact Fluorescent

 

The new CFL (compact fluorescent) bulbs are just miniature fluorescent tubes. True black light versions are available and share the characteristics of the larger tubes. Light output and wavelength varies greatly between brands and styles.

 

Black light CFL bulbs screw into a standard light socket and typically use 25-40 watts of power. Larger wattage units are typically sold in their own specialty fixture.

 

Unfortunately, the majority of CFL “black lights” are actually regular white CFL bulbs dipped into a coating that filters all non-violet light. Yes, this is absurd. The mercury inside these bulbs creates ideal UV light. The phosphors convert the UV light to white light. The coating filters all of the white light but violet. Only about 4% of light makes it out of the bulb rendering it completely useless. Yes, companies go out of their way to make this crappy product.

 

Mercury Vapor Black LightHID

 

Several stage lighting manufacturers offer a 400 watt HID mercury black light. They function very similar to a black light fluorescent tube. However, they take 5-10 minutes to turn on, they get very hot, they are very heavy, and they use a lot of electricity. The bulbs have a short life and are relatively expensive to replace.

 

These large powerful lights are sometimes preferred because they can project ultraviolet light a far distance. Otherwise, their drawbacks make them unappealing compared to fluorescent and CFL fixtures.

 

Glow Inc.'s Black Light Fixture

 

The Glow Inc. fixture projects forward more long wave ultraviolet light than seven standard 2' fluorescent black lights using less than 1 amp of electricity . However, its all aluminum enclosure is only 14" x 10" x 7" and weighs 11 pounds.

 

The fixture contains a 100 watt compact fluorescent bulb constructed with true woods glass. Behind the bulb is two efficient glass mirror reflectors. The bulb is protected by a shatter proof front glass cover. The whole unit keeps cool using convection vents.

 

As you can see, for its price, this is an amazing black light fixture.

 

Conclusion

 

If you need an inexpensive black light to use with your glow in the dark or fluorescent creations, then stick to full size or compact fluorescent tubes. LED fixtures are a viable, yet expensive alternative. However, you must make sure they incorporate 365 nm LED’s. In general, stay clear of incandescent or HID.

 

A request from the author:

 

Glow Inc. has always been at the forefront of providing free technical information on the subject of "glow in the dark". Most recently, we added the Glow in the Dark Forum so that customers can add to this free information base.

 

However, we are in desperate need of exposure on the Internet. If you enjoyed this article, please consider putting a link to it on your website, blog, or your favorite forum.

 

 

Hope you find this information interesting and useful.

 

Cheers!!

[TAGster 5]

After reading about UV light, I decided to get a black light lamp and see how it works, here is a sample I did this with a small black light lamp I got from a halloween costume shop:

 

 

 

Here is how the watches glows after two minutes of being exposed to the black light

 

 

 

But the glowing doesn´t last too much, I would say the watches glow high for about 35-40 seconds, then it dimmes to a normal glowing and after 2-3 minutes the glowing dissapear. I think this is due the exposure (charging time) only was for aprox. 2 mins, I think the longer the exposre the longer the lume keeps glowing.

 

And finally, here is the lamp I used:

 

Edited September 24, 2010 by greg_r
Admin Edit: Youtube embedding fixed

[TAGster 5]

^^^My friend moderators/admins: could anyone help me to embed the video from you tube??. I just see a blank space where it suposed to be the video. :-(

 

Thanks!!

[Baldrick 1]

ZZZZZZZZZZZZZZzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz, boys and their toys underneath the blankets ..duh..talk about 'get a life', get a brain more like!!

[trailboss99 994]

Balders!

WTF was that for?

He's just trying to illuminate us on the uses and types of black light.

 

 

Col.

[Luthier 1]

I do care (a little), how my watch glows after being on my wrist all day long.

Black light? Purple light? WTF???

For sciencific purpose - great article. Practical? Zilch.

[Wiz 0]

Nice article, but using uv light to charge lume is a bad idea. It damages the pigments.

[AllergyDoc 40]

I use a small reading lamp. Silly me.

[greg_r 81]

Balders - did ya get out of bed on the wrong side this morning? Give the poor guy a break, huh?

[Baldrick 1]

did ya get out of bed on the wrong side this morning?

 

Not out of bed yet, was too busy under the blankets, admiring the 'glow' that my DSSD throws on my 'Transformer' toy

 

Fuck me, there's a 'Glow In The Dark' forum, I gotta go sign up there, later guys

[Member X 91]

Well, horses for courses...

 

You've heard the saying about if you don't have anything nice to say, don't say anything?

[Brightlight 0]

Well, horses for courses...

 

You've heard the saying about if you don't have anything nice to say, don't say anything?

 

Yeah, but where's the fun in that?

[warcelo 0]

Really nice Topic! Thanks a lot TAGster!

I´m also a lume addicted, and i want to relume some of my watches.

 

Will you use w@tchlume or tritec? Will you DIY?

Let´s share some info!

 

Thank you again!

Edited September 23, 2010 by warcelo

[NFleischer 4,355]

Interesting, I have to brush up on my physics.

Too bad most reps have short lasting lume.

I have to say from my experience, without after market lume service, Sead's PAM's are

about the best I've seen. As good as many gens if not better.

[TAGster 5]

I do care (a little), how my watch glows after being on my wrist all day long.

Black light? Purple light? WTF???

For sciencific purpose - great article. Practical? Zilch.

 

I agree with you, is not practical but for scientific purpose is a good read, in fact more than scientific for me was a fact that fulfill my curiosity regarding how the phosphorescent stuff reacts to certain type of lights.

 

And I wanted to share this info here because I´ve noticed a lot of people that talk about the lume in their watches, super-lume, re-lume, etc.

 

Cheers!

 

 

Nice article, but using uv light to charge lume is a bad idea. It damages the pigments.

 

Thanks for the input mate.

 

Could you please give us a little more info. on why the UV light damages the pigments?, it would be interesting to know that and for sure will add value to this thread.

 

I will not use UV for charging my watches, I just found this information googling about lume and phosphorescent compounds.

 

Cheers!

 

 

I use a small reading lamp. Silly me.

 

I do the same Doc.

 

 

Really nice Topic! Thanks a lot TAGster!

I´m also a lume addicted, and i want to relume some of my watches.

 

Will you use w@tchlume or tritec? Will you DIY?

Let´s share some info!

 

Thank you again!

 

Hi mate,

 

I am still deciding about the lume product, in fact I am willing to use the Gmax ultra lume from rwgshop but is out of stock. I´ve been looking also for Tritec product because I understand they provide a "complete kit" that includes the phosphorescent powder (superluminova), the binder, applying too, etc.

 

And yes, I want to do it my self, I have a couple of cheap watches where I can experiment on.

 

Sure! I would love to share info, I think that is why we are here my friend.

 

Cheers!

 

 

Interesting, I have to brush up on my physics.

Too bad most reps have short lasting lume.

I have to say from my experience, without after market lume service, Sead's PAM's are

about the best I've seen. As good as many gens if not better.

 

Yes mate, unfortunately the reps has a ver short lasting lume, that is why I am willing to learn how to re-lume a watch to try to improve my reps lume performance.

 

I´ve not seen the Sead´s PAMs, where can I see his watches?

 

Cheers mate!

[Baldrick 1]

I wish some of you guys would lighten up

 

BTW, can anyone shed any light on the 'Glow In The Dark' forum, or perhaps shine a light in it's direction ?

[Member X 91]

I'm sure it will be very illuminating

[Luthier 1]

did ya get out of bed on the wrong side this morning?

 

Not out of bed yet, was too busy under the blankets, admiring the 'glow' that my DSSD throws on my 'Transformer' toy

 

 

Well... I do other, more pleasant things under the blanket...

:P

[sconehead 5]

did ya get out of bed on the wrong side this morning?

 

Not out of bed yet, was too busy under the blankets, admiring the 'glow' that my DSSD throws on my 'Transformer' toy

 

 

Well... I do other, more pleasant things under the blanket...

Fart?

 

 

 

 

@ Tag...don't take Baldricks comments too seriously...none of us around here do mate...he's feeling a little cranky 'tis all...

 

 

 

[TAGster 5]

did ya get out of bed on the wrong side this morning?

 

Not out of bed yet, was too busy under the blankets, admiring the 'glow' that my DSSD throws on my 'Transformer' toy

 

 

Well... I do other, more pleasant things under the blanket...

Fart?

 

 

 

 

@ Tag...don't take Baldricks comments too seriously...none of us around here do mate...he's feeling a little cranky 'tis all...

 

 

 

 

No worries mate, I do not take those comments in any serious way.

 

Cheers!

[jon k 0]

Clarification: People have said that lume on reps does not last very long.

 

This article states that lume can be recharged with black lights. Does this method NOT WORK on reps or something? If it does, I don't see why this information isn't considered useful.

[greg_r 81]

Clarification: People have said that lume on reps does not last very long.

 

This article states that lume can be recharged with black lights. Does this method NOT WORK on reps or something? If it does, I don't see why this information isn't considered useful.

 

There's good and bad lume - good lume on reps does exist but it's rare. However you charge the lume, it's not going to make much difference if the lume isn't much good in the first place.

 

My only real concern with the regular use of UV lamps to charge watch lume is that in time it is likely to damage the pigment, as Wiz said.

[debian 0]

It was mention earlier in the thread that UV light damage lume...

If that is true you should not wear your watch in sunlight.

[JoeyB 0]

It was mention earlier in the thread that UV light damage lume...

If that is true you should not wear your watch in sunlight.

I do, but I coat it with SPF24 first...

[Member X 91]

Is it the UV that bleaches the old Tritium markers on vintage subs a lovely white colour?

 

Surely such a limited range of UV from a lamp will be les damaging than the more full range that is in sunlight? (Hence you can damage your eyes and skin with too much UV, but these lights should be fine?)