Coating, Exposing Screens

[Frog]

if the m/h unit is home made, what kind of light is it? is it an m/h lamp for security lighting, or shop lighting, or is it an actual m/h bulb for photo exposure. There really is a difference. Just like led lights that have zero uv, and led lights that when configured right, seem to have serious amounts of uv output. We bought a UV meter a few years back and we saw an extreme difference between the uv output of a 1000 watt photosharp, and the 1,000 watt m/h shop lights that were in our ceiling fixtures, and I can tell you that those shop lights would have had a hard time exposing a screen. I could be wrong, you may have the proper lamp set up in your home made unit, but for others, there is a difference between actual lamps.

With that in mind, though I can't give you specifics, some emulsions play nicer with generic MH bulbs than others.

I even seem to remember an emulsion called 420 from Chromaline or someone, that rather than for potheads, was targeting just this market, this slightly higher wavelength more common in many non-industry specific bulbs.

[Dochertyscott]

if the m/h unit is home made, what kind of light is it? is it an m/h lamp for security lighting, or shop lighting, or is it an actual m/h bulb for photo exposure. There really is a difference. Just like led lights that have zero uv, and led lights that when configured right, seem to have serious amounts of uv output. We bought a UV meter a few years back and we saw an extreme difference between the uv output of a 1000 watt photosharp, and the 1,000 watt m/h shop lights that were in our ceiling fixtures, and I can tell you that those shop lights would have had a hard time exposing a screen. I could be wrong, you may have the proper lamp set up in your home made unit, but for others, there is a difference between actual lamps.

This is the metal halide im using...

http://www.sunmastergrowlamps.com.au/pdfs/80310.pdf

[Dochertyscott]

http://www.sunmastergrowlamps.com.au/pdfs/80310.pdf

[Evo]

This home made exposure unit has served me well over the last 3 years... same bulb... perhaps thats the problem?

Ding.

[abchung]

http://www.sunmastergrowlamps.com.au/pdfs/80310.pdf

Wrong metal halide lamp.... You are using a 3200Kelvin..... These metal halide only produce a little bit of light between 350 and 420nm (ref. http://www.kiwo.com/Articles/Understanding%20the%20Emulsion%20Curing%20Process%20&%20Determining%20Exposure%20Distance.pdf

You need to use metal halide lamp at 10,000Kelvin or above. They produce more 350/420 wavelength. Look at the graph when the curve represent 3200Kelvin.... very little 350/420 wavelength. But when it hits 10,000Kelvin.... There is alot more 350/420...
http://en.wikipedia.org/wiki/Color_temperature

[screenprintguy]

if the m/h unit is home made, what kind of light is it? is it an m/h lamp for security lighting, or shop lighting, or is it an actual m/h bulb for photo exposure. There really is a difference. Just like led lights that have zero uv, and led lights that when configured right, seem to have serious amounts of uv output. We bought a UV meter a few years back and we saw an extreme difference between the uv output of a 1000 watt photosharp, and the 1,000 watt m/h shop lights that were in our ceiling fixtures, and I can tell you that those shop lights would have had a hard time exposing a screen. I could be wrong, you may have the proper lamp set up in your home made unit, but for others, there is a difference between actual lamps.

This is the metal halide im using...

This one at least has a good UV spectrum, proper for growing vegetation, which is a lot closer than most shop bulbs out there, probably good for Pure Photo polymers, may have issues with slower curing emulsion like Diazos, you know who would be great to chime in on UV spectrums, Ron Hopkins with M&R/NuArc, he's been in the plate making and emulsion exposing  side of everything for a long time, way before M&R took over NuArc, this guy's knowledge of UV is pretty awesome, nice dude too. Just curious, did you create a shutter for your lamp? Just wondering your process of exposing while waiting for a draw down ect. Interesting.

http://www.sunmastergrowlamps.com.au/pdfs/80310.pdf

[Dochertyscott]

I was aware that it wasn't in the ideal spectrum, but has been much better and faster than the fluorescent homemade alternative. I don't have a shutter. I have the screens with film taped ready (in darkness) . Warm the bulb. Then grab one, put it on glass, put a flat bit of steel down with neoprene foam adhered  underneath. . Then 4kg ink pots on top of that.... All in a blink of an eye.... Ha
I know it's a bit rangi. But has always been good for my usual coating method.
 Should really get that mp3140 aye...? Any other better alternatives.
Cheers

[Gilligan]

Lol... I did similar... I would use a vacuum storage bag with black shirts on the squeegee side, then I would put a commercial grade trash bag over it all... Turn on the lamp for 3 mins then uncover for like 50 seconds (it's all coming back to me now).

Lots of good stuff about these LED units... Time will tell, but if M&R is making one, then there must be something to them. *shrug*

[Evo]

Should really get that mp3140 aye...? Any other better alternatives.
Cheers

Only buy a MSP-3140 if you are willing to deal with the issues it will cause.

Issues such as:

Proper exposure
Increased stencil detail
Increased production
Reduced incidents of re-burns


It's your decision.

[Gilligan]

Should really get that mp3140 aye...? Any other better alternatives.
Cheers

Only buy a MSP-3140 if you are willing to deal with the issues it will cause.

Issues such as:

Proper exposure
Increased stencil detail
Increased production
Reduced incidents of re-burns


It's your decision.

Seriously.

My best purchase, and the most expensive purchase I ever made... It's NEVER made a bad exposure... NEVER!!!