# Homemade Drying Cabinet



## BlackPressGr (Jun 9, 2007)

I'm about to build a drying cabinet for my new shop. I've already worked out my plans but I've read a lot of discussion about the drying system people recommend. Some people say forced air, others heat, and some say dehumdifier.

I already have a small heater that I used at my old shop in a very makeshift sort of way. But I'm very curious about the dehumidifier. If it works as well as I read, I'm all for it. Anyone have some details on the differences between these different methods?

I've also heard of using a shop vac to suck up extra water after degreasing the screen but before putting them in a drying cabinet. Anyone know anything about that?


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## Fluid (Jun 20, 2005)

I would say it depends on how fast your wanting to dry your screens. A dehumidifier will remove all the moisture out of the air which in my experience will be the fasted all around.

Using forced air to blow out the excess water in the screen after reclaiming as well as burning will help to speed up the process.


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## RichardGreaves (Nov 7, 2006)

Heating, is not drying. Dry air will suck the moisture out of the stencil. Heat will expand the air around the stencil, decreasing the relative humidity, and then the air will suck the moisture out of the stencil. Mother nature hates imbalance.

A wet-dry vacuum requires a special very thin opening in the tip to pull EXCESS water off the mesh and stencil. It is always a good idea to remove excess water which saves time evaporating it.

Beware the dangers of forced air, because it usually has oil in it and can do some damage. If that's all you have, use it, but it doesn't cover as much area as newspaper to blot, or the special vacuum tip.


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## ftembroidery (Nov 25, 2006)

I have a home-built drying cabinet that uses a dehumidifier. It not only "sucks up" moisture, it heats the air so as to get the moisture INTO the air (as Richard Greaves said, "mother nature hates an imbalance") so it can remove the moisture. It works VERY well. The only "difficulty" is, it seems dehumidifiers come in a variety of sizes that range from way too small to way too big. My dehumidifier is about 18" tall by 12"wide by 8" thick. (I'm working from memory here). The next size down wouldn't be big enough to do any good. I equated it to the difference between a battery charger that only "trickles" enough energy to keep a rarely used motorcycle battery charged and a larger but not "professional auto shop" sized battery charger. I recommend the dehumidifier route.


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## BlackPressGr (Jun 9, 2007)

Fluid said:


> I would say it depends on how fast your wanting to dry your screens.


I'm shooting for around a 20-30 minute dry time for a cabinet that can hold up to 12 screens. Obviously a full cabinet of wet screens will increase the dry time but typically I only do around 6 screens at once.


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## ftembroidery (Nov 25, 2006)

Dehumidifiers are rated by the amount of water they'll remove in 24 hours....if you decide that 12 screens hold a total of 1 quart of water, and you want them dry in half an hour, you'll need a dehumidifier rated at 48 quarts.


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## BlackPressGr (Jun 9, 2007)

Thanks for the info. I'm going tomorrow morning to purchase my materials. I'll see what they have for dehumidifiers. Worst case senario, I may purchase 2 smaller units since there will be enough room in the bottom of my cabinet.


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## Newcomb Graphix (Jul 13, 2007)

Hey all....Will anyone be willing to share their schematics of a homemade drying cabinet? If you could at least point me in the right direction that would be a big help. Thank you much for your time.


-Chris


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## BlackPressGr (Jun 9, 2007)

Well, I got the cabinet together and ran a few test screens through it. Everything seems to work fine. I built it to hold 9 screens instead of 12. I found a 30 pint dehumidifier that managed to dry a handful of soaking wet screens in around 35 minutes. The light manages to stay out as well. For never building a cabinet in my life I must say I'm quite proud of myself.



Newcomb Graphix said:


> Hey all....Will anyone be willing to share their schematics of a homemade drying cabinet? If you could at least point me in the right direction that would be a big help. Thank you much for your time.


Sadly, I keep all of my schematics in my head and a handful of measurements on paper. But if I get time over the weekend I'll see what I can do to give you an idea of what I worked with.


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## BlackPressGr (Jun 9, 2007)

Ok, here is a rough layout of the cabinet I built. The measurements are not precise since most 2x4s are acutally 1 1/2" thick. That threw me off a little but hopefully this will help point other people in the right direction.
This Cabinet can hold 9 screens that are 20x24. Originally I wanted 12 but the only dehumidifier I could get took up the place of 3 screens. I've been using it daily since I built it and it works great. My exposure unit fits right on top too.
The best part is that they forgot to charge me for any of the plywood I bought. The whole project cost me $220 and that includes the brand new 30 pint dehumidifier and all other parts.
It took 1 full day to construct but that's because I did it all myself. The friend that was supposed to help me pulled a Houdini after 30 minutes and vanished.


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## Newcomb Graphix (Jul 13, 2007)

Thanks a lot...that's a huge help


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## Chuckie C (Sep 22, 2007)

Nice cabinet.
Thanks for pictures.


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## rrc62 (Jun 2, 2007)

I use one of these to air dry. It is a blower, not a compressor, so no issues with oil. It moves enough air to completely dry a screen in less than a minute. I let them dry in the rack for another 30 minutes before using them.

PetEdge: Metro Air Force Blaster Dryer


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## marlo45 (Oct 4, 2007)

I suspect you are all refering to drying time for pre-emulsion-coated screens, right? 

I have been trying to get a good idea of the total drying time for 20x24" screens ranging from 110 to 156 mesh count; i.e drying time after degreasing + drying time after emulsion is applied. 

Can anyone give me an idea? I would definitely like to give the homeade drying cabinet a shot because i guess the alternative is to use a full day & night letting everything air dry??


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## BlackPressGr (Jun 9, 2007)

marlo45 said:


> I have been trying to get a good idea of the total drying time for 20x24" screens ranging from 110 to 156 mesh count; i.e drying time after degreasing + drying time after emulsion is applied.


What kind of emulsion are you using?

Right now I am using a dual cure liquid emulsion so my degrease and emulsion are 2 different drying steps. Typically if I am drying 4-5 screens at once, the dry time is between 20-30 minutes for each step. If I fill the cabinet with wet screens (around 10 screens) the dry time is will run around 30-45 minutes to dry all the screens. 

If you are using the sheets of emulsion (I can't think of the name right now) you can cut your drying time in half since that can be done as one step.


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## marlo45 (Oct 4, 2007)

*The emulsion is listed as: CCI DXP dual cure emulsion.* 

I am going to find out more about all this stuff when i get my kit and start experimenting. I'm a fan of teaching myself stuff so with the videos i've been watching and the useful info found here in the forum, i'm hoping i'll be ok.

I am also wondering if anyone here has successfulluy converted any bedroom furniture to a drying rack/unit? I have a dresser and an armoire that i can part with .


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## ironhead (Dec 28, 2005)

BlackPressGr said:


> Ok, here is a rough layout of the cabinet I built. The measurements are not precise since most 2x4s are acutally 1 1/2" thick. That threw me off a little but hopefully this will help point other people in the right direction.
> This Cabinet can hold 9 screens that are 20x24. Originally I wanted 12 but the only dehumidifier I could get took up the place of 3 screens. I've been using it daily since I built it and it works great. My exposure unit fits right on top too.
> The best part is that they forgot to charge me for any of the plywood I bought. The whole project cost me $220 and that includes the brand new 30 pint dehumidifier and all other parts.
> It took 1 full day to construct but that's because I did it all myself. The friend that was supposed to help me pulled a Houdini after 30 minutes and vanished.


Could you tell me what size dehumidifier are you using? Are you set up in a damp or moist area?
thanks


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## Chuckie C (Sep 22, 2007)

Do you have any vent holes in this cabinet ?


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## tomgrin (Oct 21, 2008)

Holy Sh!t thanks for the awesome thread and posts! For a newb, you guys really shared a lot in here. Can't thank enough!


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## tomgrin (Oct 21, 2008)

Would be interested to know if there are any ventilation holes in this drying rack, or if by creating openings you A) lose control of humidity; and B) possibly allow light in, which I think is the major issue with newly coated screens... 

Would also be very interested in how long people will keep a coated screen sitting around before they expose it (if it is light and humidity safe); or if there's a shelf life before you have to reclaim and redo your coating of emulsion.


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## BlackPressGr (Jun 9, 2007)

I haven't responded to this post in a while since I've been busy. My drying cabinet is no more...long live the new drying cabinet.

Since I recently upgraded all my equipment to print oversized, I needed a place to dry oversized screens. I actually took one of my work benches that someone else had built and added the cabinets underneath. Same working concept as my first cabinet. But now it can hold 18 screens, 12 of which can be 20x24 or 23x31. It works even better then the old one.

PS. If anyone is near Gainesville, FL, I am giving away my old one. Let me know if you are interested. It won't last long.


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## tdigital (Sep 14, 2008)

BlackPressGr said:


> I haven't responded to this post in a while since I've been busy. My drying cabinet is no more...long live the new drying cabinet.
> 
> Since I recently upgraded all my equipment to print oversized, I needed a place to dry oversized screens. I actually took one of my work benches that someone else had built and added the cabinets underneath. Same working concept as my first cabinet. But now it can hold 18 screens, 12 of which can be 20x24 or 23x31. It works even better then the old one.
> 
> PS. If anyone is near Gainesville, FL, I am giving away my old one. Let me know if you are interested. It won't last long.


That's what i'm talking about! Giving it away  Good stuff man, its coming back to you tenfold!


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## kylerogers (Jul 30, 2008)

Watch out! Those little ones they sell for $50 are total garbage. I bought a $50 of Amazon.com that was completely useless. Then I got a Frigidare for $150 at Lowes that works amazing. I just have my screens and the dehumidifier in a small room together and it basically turns the whole room into a drying cabinet.

I think my unit from Lowes is rated at 25 quarts.

I plan to eventually make a cabinet where my dehumidifier sits in the bottom myself.



BlackPressGr said:


> Thanks for the info. I'm going tomorrow morning to purchase my materials. I'll see what they have for dehumidifiers. Worst case senario, I may purchase 2 smaller units since there will be enough room in the bottom of my cabinet.


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## tomgrin (Oct 21, 2008)

BlackPressGr said:


> ...Since I recently upgraded all my equipment to print oversized, I needed a place to dry oversized screens. I actually took one of my work benches that someone else had built and added the cabinets underneath. Same working concept as my first cabinet. But now it can hold 18 screens, 12 of which can be 20x24 or 23x31. It works even better then the old one....


Dude!  Thanks again so much! We actually have a (50 year old) enormous work bench in our basement that would be so easy to convert; similar to your new design. 

One question though, and this might be overly obvious, but given that you have 3 columns of 6 screens per rack; where do you fit your dehumidifier? While it's not huge, it looks like it could take up at least half of the center cabinet, no? 

Thanks again man, this is killer!


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## BlackPressGr (Jun 9, 2007)

tomgrin said:


> One question though, and this might be overly obvious, but given that you have 3 columns of 6 screens per rack; where do you fit your dehumidifier? While it's not huge, it looks like it could take up at least half of the center cabinet, no?


The door on the right is just big enough to fit the dehumidifier and nothing else. I made it large enough to fit it in sideways. Then the switches on the wall to the right control the dehumidifier and the exposure so I don't have to reach inside to turn it on.


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## tomgrin (Oct 21, 2008)

Probably overkill, but any chance you'd take one more photo to help us out and show us the open-door view w/ your dehumidifier placed inside? (And which model dehumidifier did you say you were having good luck with; that also fits into that small of a space sideways?)

If I can ever return the favor, PM me, I've been a graphic artist for 15 years, just a newb to screen printing.


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## tomgrin (Oct 21, 2008)

As long as you open this cabinet light-safe, anyone have a suggestion for how long a screen can sit for once it dries the emulsion, before you think it needs to be reclaimed and re-coated? I know other than dust, arguably it should be forever; but heat/cold/natural humidity; IDK if anyone things there is a shelf-life for these coated and dried screens before they lose their effectiveness when you go to expose.


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## tpitman (Jul 30, 2007)

Here's the one I cobbled up. Holds 12 screens, has a bathroom fan in the back of the cabinet at the top, and filtered air coming in through the door in front at the bottom. My dehumidifier sits on top and drains through the wall into my washout sink, because I'm too lazy to empty that bucket, which will fill up in 12 hours here in Florida in the summer.


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## tomgrin (Oct 21, 2008)

tpitman said:


> Here's the one I cobbled up. Holds 12 screens, has a bathroom fan in the back of the cabinet at the top, and filtered air coming in through the door in front at the bottom. My dehumidifier sits on top and drains through the wall into my washout sink, because I'm too lazy to empty that bucket, which will fill up in 12 hours here in Florida in the summer.


Sweet! This one rocks too. Nice move w/ the filter in the front and the bathroom vent in the back. 

Question, I get why you'd have the dehumidifier up top to drain by gravity with a hose, but how does it actually work 'inside' the rack? Is it just conditioning the entire room? Or do you have the bathroom vent somehow connected to the dehumidifier? Guessing the room is small enough that having it up top just aids in pumping out the room to a specific level of dryness, right? 

Anyone nerdy enough to have target humidity ranges for a rack system or room w/ drying screens? I think a cheap humidity meter might be well worth the coin...


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## tpitman (Jul 30, 2007)

It dehumidifies the whole darkroom. I have it set for 40% humidity, and it turns on and off as necessary. In my old darkroom in my garage at home my washout sink was also in my darkroom. The whole space was about 5" x 9". When I'd reclaim screens with a pressure washer, the humidity would climb, but the dehumidifier would drop it down by 10 - 15% within 2-3 minutes.

It might dry screens and emulsion a little quicker if I had it ducted directly into the cabinet, and the dehumidifier has a simple mesh "filter" to keep most of the crap out of it, but the way I've got it set up seems to be efficient enough. Since I work by myself, I'm not cycling screens through the cabinet that fast, anyway. I've always got a few hours if need be. Additionally, I also have a couple of 25" x 36" screens I use for yard signs, and when I coat them, I just have them sit across a couple of boxes on the floor of the darkroom to dry before exposing, and they also get the benefit of the dehumidifed air.


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## tomgrin (Oct 21, 2008)

Sweet! Thanks. What finished size and material do you use for yard signs if you don't mind me asking? Hadn't thought of how many contractor friends we have always asking for signage, etc. woohoo! New areas to print!


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## tpitman (Jul 30, 2007)

So far I've been doing the 24" x 18" coroplast with the 18" vertical flutes. It's easy enough to print, but the ink is more expensive than plastisol, and it stinks. You also need to add a touch of thinner/retarder to it, and you have to get all your stuff set up because you can't let the screens sit with ink in them as the ink starts setting up pretty quickly. You need to be printing about 3 or so a minute. Do a print stroke, then a flood stroke to cover the open areas of the stencil. Also, draw the squeegie at a slight angle from perpendicular to your stroke direction to keep the squeegie blade from stumbling over the flutes. Use a 230 mesh. I also use a respirator while printing and cleanup to keep what few brain cells I have left. Don't mix up more ink than you'll use in 30 - 40 minutes, as it's an air dry ink and starts setting up in the cup. The signs dry to the touch in about 30 minutes, but I let them dry for 12 hours before stacking. And when you're done, clean up the screen and squeegie immediately. Once I'm set up, I print 50 in about a half hour. The worst part of the job is the cleanup. Make sure you ventilate the workspace also, because that smell will hang in the air for quite a while. Don't do this in your house.


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## tomgrin (Oct 21, 2008)

tpitman: thanks man, that was awesome (I know it was off-topic, but man, that was a killer tutorial; thanks!)


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## tomgrin (Oct 21, 2008)

Update: (Back on thread topic): So we built our first screen drying cabinet, ended up vertical and we're pretty psyched. Sitting a Goldstar 40pt Dehumidifier inside of it (wanted to get something a tad smaller for the sake of maximizing space, but got a killer deal off craigslist (like new) so we grabbed it. Degreased some new screens, put them inside to dry out. Now - there's no heat or fans, just the dehumidifier. Seemed to dry a bit faster when we kept the door slightly open to let some air circulate, otherwise it seemed to turn into a bit of a sauna inside because the moisture just kept recirculating? 

We coated w/ emulsion, and back in they went and the latches went on. (Should be) lightsafe. My question for anyone who's built their own rack like this is, should we really consider venting the front and back (heater grills from normal baseboard vents seem to be common?), so that there is SOME air circulation/exhaust? And if so, how do you keep it light safe, while using those grills? 

Thanks! Really anxious to see the amount of time it'll take to dry the emulsion before we can bust them out and expose on our light table. We currently have 3 coated screens (20x24) in a 5' tall cabinet. Can post pics tomorrow if anyone wants to laugh at our hack job!


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## tpitman (Jul 30, 2007)

I think most people who put the dehumidifier inside the cabinet also have fans pulling air into and out of the cabinet to introduce fresh air. Sealing the door and using filters on the air coming in is to keep dust from contaminating the emulsion. Dehumidifers produce a certain amount of heat on their own, plus have a fan that moves air through it, but since it dumps the water into a bucket, if you're not either bringing fresh air in or draining that bucket constantly, you're just holding that moisture in, as you've apparently found out. If you're going to dedicate the dehumidifier to the drying cabinet, you'd do better to put it outside and duct the dry air coming out of the dehumidifer into the cabinet, then provide an exhaust vent in the cabinet for the air to exit after it had pulled the moisture from your screens.


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## n.signia (Nov 21, 2007)

tomgrin said:


> Update: (Back on thread topic): So we built our first screen drying cabinet, ended up vertical and we're pretty psyched. Sitting a Goldstar 40pt Dehumidifier inside of it (wanted to get something a tad smaller for the sake of maximizing space, but got a killer deal off craigslist (like new) so we grabbed it. Degreased some new screens, put them inside to dry out. Now - there's no heat or fans, just the dehumidifier. Seemed to dry a bit faster when we kept the door slightly open to let some air circulate, otherwise it seemed to turn into a bit of a sauna inside because the moisture just kept recirculating?
> 
> We coated w/ emulsion, and back in they went and the latches went on. (Should be) lightsafe. My question for anyone who's built their own rack like this is, should we really consider venting the front and back (heater grills from normal baseboard vents seem to be common?), so that there is SOME air circulation/exhaust? And if so, how do you keep it light safe, while using those grills?
> 
> Thanks! Really anxious to see the amount of time it'll take to dry the emulsion before we can bust them out and expose on our light table. We currently have 3 coated screens (20x24) in a 5' tall cabinet. Can post pics tomorrow if anyone wants to laugh at our hack job!


to keep your cabinet light safe and also vented, ust the gills you mentioned with a square of black foam attached on the inside of the cabinet over the gill vent. the foam is porus and spongee, and air can go through it, I dont know what its "name" is but Home depot should carry it.


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## tomgrin (Oct 21, 2008)

Thanks! Our situation is a little bit less ideal as a shop w/ a designated light-safe dark room w/o any water (ie: washout booth, etc). We're in an open, unfinished basement (For now, hopefully not come this time next year), appx 1000sf or so; it's relatively dry as far as basements go, but that said, it's definitely got natural humidity in the room. So while we've looked at a bunch of different approaches and diagrams, we're thinking that dehumidifier outside of the light-safe screen drying rack would be working to dehumidify the entire basement as well as the targeted area. But you bring up killer points about needing ventilation/circulation, etc. 

This model dehumidifier does have an easy garden hose adaptor which is pretty slick, but A) it's currently residing on the floor of the cabinet, so there's not a lot of gravity to port the hose out to a drain; and B) will it be enough if we can port the top back and the bottom front? The basement is set to go light-safe whenever we want under yellow bug lights (plenty of visibility!). 

Definitely seems like we have to port out some grills/vents; possibly the filter in the front bottom like someone else had in their picture and a bathroom vent on the upper back. Any suggestions on whether to use just the grill up in the back or the actual exhaust fan to 'pull' the warmer (heat rises) air out and move the cooler air in from the bottom? Do you think that'll be enough to keep the dehum inside the box? Man, we owe everyone on this forum a beer. If you're going to any tradeshows let us know and if we cross paths, maybe we'll have to pick up a small tab!  thanks again.


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## tomgrin (Oct 21, 2008)

n.signia said:


> to keep your cabinet light safe and also vented, ust the gills you mentioned with a square of black foam attached on the inside of the cabinet over the gill vent. the foam is porus and spongee, and air can go through it, I dont know what its "name" is but Home depot should carry it.


Sweet, that's what we were thinking, but we weren't sure about the light-safeness of soft foam. My roommate / partner in this endeavor, his family actually owns a rubber molding factory (if anyone needs anything rubber of any size/shape/density, let us know, seriously - seals for doors, grommets, etc.), so that shouldn't be a problem! 

Any idea if a standard home depot air filter (the white ones for a forced air heat/AC system) will technically be light-safe as well as do it's job in filtering any dust from coming in? I'm thinking avoiding painting the thing as it might clog the filter's purpose...


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## tpitman (Jul 30, 2007)

If you can duct the exhaust air from the dehumidifier (that's the dry air) into the box, and just have a vent to let it out, that would do it. My dehumidifer has a flimsy "filter" on it's intake side that gets most of the dust out. BTW, mine is the photo with the bath fan in the back.


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## fdkss03 (Apr 13, 2011)

tpitman said:


> I think most people who put the dehumidifier inside the cabinet also have fans pulling air into and out of the cabinet to introduce fresh air. Sealing the door and using filters on the air coming in is to keep dust from contaminating the emulsion. Dehumidifers produce a certain amount of heat on their own, plus have a fan that moves air through it, but since it dumps the water into a bucket, if you're not either bringing fresh air in or draining that bucket constantly, you're just holding that moisture in, as you've apparently found out. If you're going to dedicate the dehumidifier to the drying cabinet, you'd do better to put it outside and duct the dry air coming out of the dehumidifer into the cabinet, then provide an exhaust vent in the cabinet for the air to exit after it had pulled the moisture from your screens.


 
could you have your dehumidifier in its own portion of the cabinet, with a hole cut in that side and a filter... that way the dehumidifier can pull air in on its own from the outside. Of course, non dehumidified air will get in, but that will happen in any case once its turned off.

then on the other end of the cabinet after the screens put another vented grate with black foam on the inside to light protect it.


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## yellowdog (Aug 21, 2011)

tomgrin said:


> Update: (Back on thread topic): So we built our first screen drying cabinet, ended up vertical and we're pretty psyched. Sitting a Goldstar 40pt Dehumidifier inside of it (wanted to get something a tad smaller for the sake of maximizing space, but got a killer deal off craigslist (like new) so we grabbed it. Degreased some new screens, put them inside to dry out. Now - there's no heat or fans, just the dehumidifier. Seemed to dry a bit faster when we kept the door slightly open to let some air circulate, otherwise it seemed to turn into a bit of a sauna inside because the moisture just kept recirculating?
> 
> We coated w/ emulsion, and back in they went and the latches went on. (Should be) lightsafe. My question for anyone who's built their own rack like this is, should we really consider venting the front and back (heater grills from normal baseboard vents seem to be common?), so that there is SOME air circulation/exhaust? And if so, how do you keep it light safe, while using those grills?
> 
> Thanks! Really anxious to see the amount of time it'll take to dry the emulsion before we can bust them out and expose on our light table. We currently have 3 coated screens (20x24) in a 5' tall cabinet. Can post pics tomorrow if anyone wants to laugh at our hack job!


I am very interested to see some photos of what you've made. We are finishing our 5ft light-safe cupboard with dehumidifier tonight. Having read forums and got information from everywhere it seems we will have produced almost the same product!


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## Gilligan (Dec 11, 2009)

Use baffles to keep the light out of your vents.

*!i!* type of thing, air passes through the gaps but light won't be able to make all those bends. If it's painted matte black then assembled it would be even better.


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