[dodger]

Hey guys, I don’t know if this is going to help anyone out there or not but I just learned about it and thought I would share the knowledge. I am building an exposure unit and have been spending all day on the phone looking for glass that has no UV filter. Whenever I ask that, the people I’m talking to seem to have no clue on the subject; all but one. I got ahold of a guy (Trini) and he told me about a product called Starfire or Starphire glass. Now according to him even clear glass has some uv blocking properties due to the content of iron in the glass this is also what give it the green hue. However, this product was created to not have the iron thus removing any hue and giving a completely clear glass. The byproduct of this is that by removing the iron content of the glass they then removed what UV blocking characteristics that clear glass has. I looked into a bit online and what he said was confirmed that clear glass bocks 30% of UV light and new clear glasses can block up to 70%. Starfire will run you more but if you sorce it well then you can get a piece for around $12 a square foot for 3/8th thickness. So if you are looking for glass to go on your exposure unit I would recommend using Starfire it’s what I’m ordering. And if you in the Houston area heres the link to the supplier I am using. glass water bottles plate windows at clearglass.cc

 

[m_short]

Is there information on how the heat resistance is with this glass? Depending on the light source you can be putting out a whole ton of heat during the exposure process.

 

[dodger]

I personally don't know but I'm sure it can be found online. I am using Blacklights for my box so heat wasn't an issue

 

[Jsaladin]

I bought a piece of iron free glass for my exposure unit. Took me a while to find some in my area but when I did the guy that had it was so happy to sell me some he gave a my glass for 4 dollars a square foot. I said thank you and have a good day...

 

[dodger]

how on earth did you pull that off? Why was he so action to get ride of it? how are you liking by the way

 

[Jsaladin]

it was an auto glass/window glass store. He got excited when I called. I wonder if it was just sitting in the back for a while or something. I got 1/4 inch thick glass. I love my exposure unit. I have a 1000 watt MH light and a vacume hold down. It may not look like a $1000 exposure unit you could go and buy, but I bet it performs like one.

 

[dodger]

well that was some good luck, and that answers your heat question m_short. If 1/4th can stand up to a Metal Halogen then it will stand up to anything

 

[PositiveDave]

uv is not uv.
Most glass cuts off wavelengths below 300nm, the most important wavelength for a Hg halide lamp is 365nm and that is what emulsions are most sensitive to.

 

[m_short]

well that was some good luck, and that answers your heat question m_short. If 1/4th can stand up to a Metal Halogen then it will stand up to anything

It does to a point. My question really was aimed towards the thought of a 3kw bulb and running through 200+ screens a day with the glass.