exposure build question.

[chrispunx]

exposure unit build question... - T-Shirt Forums

[Aaron Gein]

You might want to post your question directly here. Your images aren't visible to anyone that isn't logged into the T-Shirt Forums.

[chrispunx]

really? damn sorry.

[chrispunx]

hi guys i've been lurking and posting for a while and i plan on building my own exposure unit. the question i have for you is this: what should i do with this-



the aluminum lamp, i guess thats what you can call it.

my build is a simple, based on the video i seen thats been posted a few times. my(shitty paint) blue prints:


does anyone have any suggestions? is this a decent setup? what adjustments would you make?

[steve w]

what kind of bulb are you using?
if it's 200W or less, just go buy a 500W halogen at Home Depot

[Aaron Gein]

What Steve said.

[marvinc02]

with that image size, 3 ft seems sort of far, drop it to 24"

[chrispunx]

what kind of bulb are you using?
if it's 200W or less, just go buy a 500W halogen at Home Depot

400w metal halide bulb.

with that image size, 3 ft seems sort of far, drop it to 24"

with the fixture and bulb that i've bought being so big its a little over a foot, so from the tip of the bulb it would be about 24"

[paul204]

Distance from bulb to glass should be 1.5x the diagonal of your image. 24" distance should be used to burn images with 16" diagonal max, or about 12"x12". If you burn too close you will expose the centre of your image before the edges.

I burn with really thick stencils, so my times are a bit longer, but don't expect this to be quick. I searched high and low for a bulb that would fit into a standard MH fixture that peaked output closest to the 320nm you want to burn emulsion. I am using a 1000w ballast and with this bulb my burn times are still about 20 minutes for white mesh and 30 for yellow, burning to a solid step 7 on a 21 step scale. That's from 48 inches though, burning 18x24s you need that kind of distance to get an even exposure.

Build a vacuum frame, too.

[chrispunx]

i'm looking for what to do about the aluminum lamp specifically. and any other suggestions are welcome.