Where to buy UV lights for a diy exposure unit

Hi there,

I am in the process of making a home polymer exposure unit. I want to be sure I am purchasing the right bulbs. I have googled “white uv lights tube” but am bombarded with too much info. As I live in a tiny town in Georgia, I will need to purchase lights online. Any suggestions? Could people tell me exactly what they use? Thanks!

Margot

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Look for unfiltered black light bulbs.
A google search will bring up information on home made exposure units. T-shirt printers, circuit board makers and photopolymer printers all need the same kind of UV waves.

The bulbs I have in my unit are labeled with this.
GE Black Light
F20T12-BL
20W USA

You will also want to have an exposure calculator. It is a little piece of film with gradient screens to help you determine the correct exposure time. Sometimes called Step Wedge. There is another name, starts with an ST, but escapes me at the moment.

Thank you so much!

Margot

The step wedge used here is a transmission grayscale or platemakers grayscale. The Stouffer 21-step is common but there are others such as Fuji. The instructions for the specific plate material will tell what step should be solid for a normal exposure. Different brands and varieties have different exposures.