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screen printing => Equipment => Topic started by: Gilligan on August 09, 2012, 03:42:08 PM
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I'm finally about to build a screen cabinet/drying box.
I figured it would be good to put one of these puppies in there.
Remote display is obviously preferred and of course CHEAP! :)
What do you guys recommend.
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screw that, go to walmart and get a $7 one. I have one that is temp and humidity. You don't really need one if you have a dehumidifier in there. It's going to be dry My cabinet will knock screens down in about 30-45 minutes for a rack of 25.
And there isn't a need for a heater. The dehumidifier puts the temp in the cabinet up to about 90-95. Most heaters shut off at 80-85.
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I have a dehumidifier but I am in South Louisiana... it's like 100% humidity outside every day. ;)
Oh, and I don't shop at Walmart... you know me, I'm a liberal like that. ;)
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radio shack has them too i think. i wouldn't worry about it, humidity here is bad as well, but the dehumidifier will really pull that out. I have mine on an AC condensation pump that runs up to the drain lines going to the back of the building. Our darkroom is in the middle of the building...so not easy way other than to drain the bucket and I had no desire to do that.
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get a dehumidifier!
As Brad said, plumb the outlet and forget about it. Our 305 are dry and ready in about 10 min (have moisture meter to measure them so we know they are ready rather than guessing).
pierre
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I have a dehumidifier ...
Tada!
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I have a dehumidifier ...
Tada!
DUH! The funny part is, I did read the post, but spaced out and by the time I wrote the follow up forgot what it said. So much for getting good help around here . . .
pierre
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the best dehumidifiers are the old ones. none of this energy star crap. also, I prefer the ones with switches rather than a control panel. The old ones come back on if the power goes out, most of the new ones have to bu turned back on manually.
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I agree. I have a modern high tech LG now sitting outside, and an older Kenmore doing duty in the drying cabinet.
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Radio shack has a pretty sweet temp/RH unit with a remote sensor, but it's a bit spendy. IIRC I paid $40 a few years back.
Kind of senseless considering we vary from 12%-25% RH 360 days of the year or so, but those five days of the year, I'm not out of the loop. ;D
Might be nice to have a cabinet remote sensor, and have the other part just in the screen room, see if you can store dry screens outside the cab safely, and to keep an eye on temp for emulsion as well.
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What are the max temps I should keep the emulsion at?
That dehumidifier puts out a fair amount of heat.
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We keep our dark room at about 75 degrees and 40% humidity. We bought a nice litte dehumidifier from Lowes a while back and it stuggles to keep it at 40%. I think the humidity is more important than temp, and we've had our dark room at 68 degrees to 90 and everything in between without any noticeable difference in dry times. But 60% humidy versus 45%, huge difference in dry times.
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buy a used cheapie on CL, old dehumidifiers worked better. Same thing goes for dishwashers.
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buy a used cheapie on CL, old dehumidifiers worked better. Same thing goes for dishwashers.
I'm not so sure about that. My first job was at a retirement home in the kitchen, washing dishes, and the old guy I worked with really slacked off!
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buy a used cheapie on CL, old dehumidifiers worked better. Same thing goes for dishwashers.
I'm not so sure about that. My first job was at a retirement home in the kitchen, washing dishes, and the old guy I worked with really slacked off!
DAMN! I was gonna make that joke. Doing it anyway!
Hmm our oldest daughter complained more and more, so we got a new one. ;)
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depends on the dehumidifier -
http://www.grainger.com/Grainger/wwg/search.shtml?op=search&N=25517&in_dim_search=1 (http://www.grainger.com/Grainger/wwg/search.shtml?op=search&N=25517&in_dim_search=1)
30, 50, 65, 104 pints per hour @ a certain RH will indicate how effective the dehumidifier will be at a certain temperature
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What are the max temps I should keep the emulsion at?
That dehumidifier puts out a fair amount of heat.
I don't worry too much about coated screens since they turn over fast, but if the screen room is over 90 degrees or so I stick it in the fridge for the hot part of the day. Not sure about photopolymers, but diazo doesn't like hot.
Probably wouldn't be a huge issue for us since a gallon rarely lasts a month in the summer, but if you're pushing your shelf life it may be more of a concern.
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ok , on the hygrometer Radio shack should be aprx 19-20 dollars cheap investment
get one it tells you what your humidity level is
a de humidifier will lower the humidity level the hygrometer tells you were you are at and what to keep it at
the sweet spot for emulsion is 32 % humidity , under 40% and I am happy
Good luck
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We keep our dark room at about 75 degrees and 40% humidity. We bought a nice litte dehumidifier from Lowes a while back and it stuggles to keep it at 40%. I think the humidity is more important than temp, and we've had our dark room at 68 degrees to 90 and everything in between without any noticeable difference in dry times. But 60% humidy versus 45%, huge difference in dry times.
Definitely right Alan. Low humidity and air circulation are most important. If you are using a pure photo polymer emulsion it hates the heat.
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"heat" is a very subjective term.
Give me some actual numbers.
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From Kiwo:
5. DRYING
Dry emulsion coated screens in complete darkness, or under
safelight conditions, in a horizontal position with the substrate side
facing down. Temperature, relative humidity and airflow affect the
drying time. Screens must be dried thoroughly before exposing to
achieve highest chemical (ink and ink cleaners) and mechanical
(abrasion) resistance. Environmental conditions play a vital role.
Temperatures of 86°-104°F (30°-40°C) with a relative humidity of
30% - 50% maximum and moderate airflow are optimum conditions.
Drying at room temperature and in uncontrolled conditions may lead
to inconsistent results and varying screen resistance.
TIP: Keep screens and all screen handling areas dry until exposure
is complete. This includes storage, exposure preparation, and
exposure areas, as photo emulsions reabsorb moisture if
reintroduced to high humidity environments. Emulsions do not
become humidity resistant until exposure, washout and drying are
complete.
Looks like 104 is the high recommened for most emulsions. I keep my mine at 85 or less because my I-jet does not like 85 or higher in the darkroom. She is a beotch. The humidity level is the most important factor, I think?
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Thank you for that info.
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My dehumidifier brings my cabinet up to about 90-95
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mine does about the same as frogs
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heat can affect emulsions , especially pure photo polymer emulsions. as a supplier we keep emulsions stored in the basement of the warehouse during the summer months.
Humidity affects the proper drying of the stencil , even if it feels dry to the touch a humidity area can allow moisture to remain in the stencil , this will affect proper exposure , resolution and durability.
so an inexpensive hygrometer is a low investment for a long term solution
just my opinion