please please please help me with qtx

[jerboy]

i've been having nightmares with qtx.

i've done all kinds of research and looked and looked and tried and tried other methods and i'm still in exposure hell.

i'm using 200 mesh yellow screens, coated once on each side with qtx, exposing over a 700 watt halogen work light, roughly 24 inches from the screen.

i'm getting 26 minute exposure times!!!

i know this can't be right, even then sometimes it will wash out, just as i think this is the sharp properly exposed screen thats going to work, it starts washing out. i did step tests and all that, anything under 20 minutes and the whole screen just washes out.

what on earth am i doing wrong?? has anybody else had this experience with qtx?

[Tom]

Another guy had the same problems a few weeks back.

305 Mesh, 2 500w Work Lights, Exposure issues

[Andymac]

did you take the cage and the glass off your light? is the light really old? Halogen are not all created equal, maybe yours has not much UV.

do you have a picture of your coating? and setup? that helps the doctors at the clinic tell what kind of STD you have. (Stupid Technical Dilemma)

if emulsion is coming off, it could be: underexposed, or you are coating shitty (too thick), or you are coating it with old emulsion, or you are coating the screens when they are still wet.

[jerboy]

i thought it might be the age of the emulsion, but i got a new pot and have the same issues. i'm coating pretty evenly (sorry don't have pics right now), i'm using the exact same method i used when working in pro shops, but there we had a pimp exposure unit and i'm just using work lights at home, i never had a problem with them in the shop.

i have removed the glass and the cages from the work lights. in the past i used unfiltered blacklights with the same result, i was sure that the halogens would be faster.

its just weird that even after 20 minutes its still underexposed. i'll try to get some photos up later.

thanks.

[furturtle]

halogens suck with qtx. I never got a good exposure and I was using two 500 watt. I bought a 1000 watt metal halide and all my problems vanished. My advice: spend money.

[Tom]

+1 on the metal halide. Ive a 400w unit I built myself. It is the single best decision i made print wise followed by buying a press with micros.
Process pics here: Mercury Vapour exposure unit:

[halfmassive]

I'm sure the metal halides rule but I get perfectly fine exposure with qtx and 2 500 watt hAlogens. Ive mentioned my set up in previous posts but with one coat of qtx on both sides and the lights about 20 inches away I get exposure times a little over 5 minutes. This has worked for me for about two years and as long as I don't put the emulsion on too thick like when its cold in my garage space I never have any serious issues with exposure. I also have the cages and glass removed.

[boatdreams]

I get insane detail with two 500 watt halogens and QTX. Roughly 26 inches from the glass, four minute exposures. Great stuff every time.
26 minutes and underexposed? Something's definitely wrong, but I'm stumped. Where are you storing the unused emulsion?

[jerboy]

would the fact that they screens are drying in my basement have any effect? i've got a dehumidifier and fans outside of the box where they cure. the screens are spaced apart with skateboard wheels to let air flow but its the only other thing i can think of.

the lights are actually TWO 700 watt lights, i tried with both lights for 1400 watts of halogen goodness but still came out with the same results.

and thanks for the responses, but i just can't switch to new lights right now, if i spend anymore cash on this without actually making some cash back, then my wife is going to kill me (ok she won't kill me, but i'll have to listen to that sigh, and i just don't want to hear that right now.)

thanks again for the comments and tips.

[boatdreams]

Good call with the fan and dehumidifier. How long are you letting them dry before exposing?