Post reclaim drying

[tpitman]

Looked to make something on the cheap. 2x4s and cheap 1/2" pvc pipe for irrigation (not the Sch 40).
Build the frame and use a spade bit to bore the holes for the pipe to pass through the top and middle horizontal pieces, and just enough bored on the bottom to hold the pipe in place.
Cover the top with something to keep dust from falling straight down and you're good.
This one is in the corner of my office. I had it in my darkroom with my drying cabinet and exposure unit when I was in a warehouse and had more room.

[Homer]

clean compressed air. blast for about 45 seconds if you take your time... ready to coat in about half hour.

[Sbrem]

picked up a screen dryer at an auction about 20 years ago, best thing since sliced bread at the time...

Steve

[jvanick]

picked up a screen dryer at an auction about 20 years ago, best thing since sliced bread at the time...

we have a vastex dryer, but I still get water spots if I put them in there...  so vertical it has to be due to the hard water here.

[Screen Dan]

we vacuum ours after reclaim/degrease and put them in a screen rack.  We like to double-space them in the rack.  It helps speed up drying.  Then we wheel it into a 7'x7' drying room with a small 1000w heater w/fan and a MASSIVE industrial dehumidifier.  The room varies between 105 and 120, usually lives around 10% RH.  Screens are ready to coat in 15-20 minutes.  Put back in after coating.  Ready to mask in another 15-20 minutes.

We get random water spots that we cannot for the life of us figure out.  Only on the 150-S.  We tried drying more thoroughly, a bunch of different degreasers, etc.  No dice.  It's not constant.  There is no pattern.  Perhaps our water is hard...sometimes? 

[ebscreen]

  Perhaps our water is hard...sometimes?

Water quality absolutely changes throughout the year. A summer ago we had an algae bloom in our supply,
the water department notified everyone so it was at least obvious to me what the problem was when our
screens started going super wonky, likely from whatever they used to kill the algae.

[jvanick]

We had no such issues with hard water when running out of our house, but there we were on a well, with a water softener...

we're planning on buying a building in 2 years or so... when that happens, I'll likely be installing a industrial-sized water softener/filtration system...

-J

[ABuffington]

If you have good filtered air and an air gun you can speed this up and eliminate the hard water issues. Spray white paper with your air gun and let it sit overnight to see if any oil spots form, these would be pinholes downline.  We have a gun from Japan that I will glady offer up if you are willing to part with 200+ dollars that has a patented gizmo that spreads the air out to a 3-4 inch width to remove water on a 23x31 in about 20 seconds or less. You can do similarly with a typical air gun, just takes far longer.   Drying off the frames, the creases, and mesh cuts the time to 1/4 of normal in a dryin gchamber.  A heated closet/room/screen dryer is essential.  On a rainy day with high humidity it can take an hour or more to completely dry the mesh.  We cycle to coat in about 20 minutes from degrease depending on mesh count with this system.  We have hard water here as well in LA, so getting all the water off before putting in a hot room with dehumidifdier (90F) helps prevent hard water circles or deposits.  Vacuuming also works with the wide screen vacs, but they need to be kept clean and free of contaminants.

[Maxie]

Al, do you dry screens horizontally or vertically?
Can we dry washed and coated screens in the same drying room?

[Screen Dan]

Can we dry washed and coated screens in the same drying room?

We do.  Sometimes on heavy flow days there are over 100 screens in there at a time.  Some drying after reclaim, some after coating and some after developing.  That's why I got the massive industrial dehumidifier.  No problems so far...and it's been many many years.

[ABuffington]

Hello Maxie,

If you use compressed air to get off the majority of the water they can be dried horizontally or vertically.  It has to be air that has gone through 2 sets of oil and water separators, one at the compressor and one set before the gun.  I have found drying wet screens vertically introduces contamination from the crease between the mesh and frame.  Hard water causes water deposits to form and air or vacuum removal really helps.

As far as storing reclaimed screens with coated screens, definitely not a good idea.  Coated screens act like sponges and absorb the humidity from the air caused by wet screens, nearby devolping or reclaiming. If you must dry freshly coated screens with dry coated screens allow them to dry overnight to keep screens dry. Dehumidifiers can quickly keep air balanced but you need to have dehumidifiers large enough to dry bigger rooms.   Keep sinks outside the room as well for this reason and use vapor barrier plastic sheets like they use in  market cold rooms to keep water vapor from the sink outside the storage and exposure room. It helps to dry reclaimed screens in their own room with heat at 90-100Fand a dehumidifier and fans to rapidly circulate the air.  The larger the room the better.  Large air volumes (larger drying rooms) can hold more humidty and not jump in humidity levels like a small closet or DIY cabinet. Commercial dryers exhaust the air and do a great job of drying the screens.  If yours has an exhaust vent run dryer ducting outside of the screen storage area if it is in the same room as screen storage.

I also recommend that coating be done before the shop closes for the night to make sure screens are free of any moisture before exposure and to allow as much drying time as possible.  A moisture meter is the only way to know if dry coated screens are dry enough to shoot in cases where you must store reclaimed and freshly coated screens in the same room. (Not cheap, easier to just separate the processes into different rooms.  Too many shops coat, check by hand to see if the surface is dry after only 30 minutes of dry time.  The inside of the emulsion can be like jello and will not expose properly.  If you print discharge you will see the screen break down sooner, often de-laminating from the screen.  Exposure is inconsistent and the more you rush screens through the drying and exposure process, the sooner they will break down.   Screen storage should be very dry, in the 35%-50% range. 

All of this is dependent on ambient humidity.  If you are in the tropics, a controlled dry storage area is a must, if you are in Las Vegas, Phoenix, or Israel, the ambient humidity is so low that you can dry faster, shoot sooner, and expose quicker and never need a de-humidifier.  In winter a lot of the US is very dry when it is cold.  Sometimes a humidifier is needed to increase ambient humidity prevent emulsion from cracking during production.  A wall mounted hygrometer to measure humidity and temp helps create predictable exposures, (very inexpensive tool).   Quite often exposure times are different in low vs high humidity on the same emulsion and the same exposure unit.   Maintaining the room via air conditioning and a de-humidifiers year round can help my emulsion reach non stop production consistently everyday.  In So-Cal it is normally perfect at 35%, but in winter when it rains exposure times can be slightly longer.

If anyone is coming to the ISS Dallas show next week I will be at booth 741 to talk shop.

We are testing a Starlight right now and will have times for all of our emulsions shortly. 


Al

[BorisB]

Can we dry washed and coated screens in the same drying room?

We do.  Sometimes on heavy flow days there are over 100 screens in there at a time.  Some drying after reclaim, some after coating and some after developing.  That's why I got the massive industrial dehumidifier.  No problems so far...and it's been many many years.

We do it as well. We use  Grunig G-Dry 570 cabinet. All drying is done in it.  We cycle through 50-60 Screens a day. We have no issues with screen quality. We added two small humidifiers in it to speed a process a bit.

[Grumpy Ole Artist]

After reclaim, I rack screens rotated 45 degrees, & angled downward from one rack level to the next...all excess water drips down from corner at back edge of rack, & has no affect on lower, (subsequently racked) screens