[Shannon1576]

New to screen printing and need to know the exposure time for QX-5 Blue using a 250 watt photoflood blub hanging about 12 inch from screen?

 

[miktoxic]

i use a 500 watt halogen hanging 16 inches from screen using pink emulsion (the most common diazo based emulsion for textile work, i believe) and it takes me 13 and 1/2 minutes to expose.

i just googled what a photoflood bulb is. don't know if it's going to give you the intense exposure of a halogen.

 

[Naptime]

only you can figure out the correct exposure time for your setup, your lighting, your temperature, your humidity, your thickness of stencil, and your emulsion, and a number of other factors.

ya gotta do the testing.

there will be many people that will tell you numbers. but the truth is, without knowing all of YOUR variabls, their numbers will mean nothing.

do yourself a HUGE favor, and buy an exposure calculator. their like 30-40 bucks, but they will last you a lifetime, and will save you hundreds or even thousands on wasted emulsion, time, and headache.

if you can't afford a calculator, do a step test. there are lots of videos on youtube showing the process.

this is the only way to know YOUR exposure time.

 

[miktoxic]

here's a link to a tutorial on how to do a step test. it also includes a link for the actual graphic which you can download and print, then expose on your screen. that is if you can print your own films. if not, you'll have to order one from a supply house.

-good luck!