Screen Printing Forum

i'm using an at home set up. i have 250 watt bulbs, and i'm using the hot pink-ish emulsion, i have done the wedge test a few times and no matter how long i leave it up the lamps (hours, and less) it still washes out. i have a piece of foam underneath the screen the transparency is on top and there is a piece of glass over it.

yes i know this sounds completely ghetto, but can someone help troubleshoot. i have a major deadline and not enough money to spend or time.

if that emulsion is qtx it is very fast but a regular light bulb won't do it. use a bank of flouresent lights or expose your screens in the sun for 30 seconds to 1 minute.

Emulsion (after it has completely dried) is exposed with UV light. At the very least, you'll need UNFILTERED UV light tubes (several, close together and 2-3 inches away from the glass). The unfiltered look very pale blue to white when on, do NOT use the novelty type that shine purple-blue that make things glow (halloween type lights).

As suggested, you can also use the sun. It IS the best source of UV light. It is, however, unpredictable (weather, time of day, or even night).

Some people use 500 to 1000 watts of halogen light. It works, but it is among the poorest sources of man-made UV light available. In fact, halogen lights put off more energy in the form of HEAT than light. The best source of man-made UV light you can get is a metal-halide bulb. They require a ballast, and since they are not an "instant-on" bulb but require time to "warm-up", you'll need to make a simple shutter to block the light so you can expose your screen for the necessary amount of time with the bulb putting out its maximum power (light). Often, you can get these light fixtures/ballasts/bulbs cheaply or even for free. Many warehouses and school gymnasiums replace them from time to time. Talk to your local lighting contractor/electrician. Otherwise, if you're going to get screen printing industry specific equipment (MH exposure machine), be prepared for a large layout of money.