Image washout time?

[Parker 1]

Just wondering how long it takes, on average, for some of you to wash an image out of a screen. 

Example this morning I was washing out a 7 color job and I timed myself on 3 of the screens. 
All screens are at 65lpi, and mesh ranged from 230 to 280.

My average on the 3 screens was 8min45sec. Longest taking 10 min the shortest being about 8 min.  This is the time it took for me to remove the film, start the exposure unit, wash the screen and replace it into the drying cabinet.

[ebscreen]

Sounds about right.

Just like with reclaiming, a post exposure dip tank (water only) can speed this up a bit.

[Frog]

I just did three, and I am a little closer to 5-6 minutes on each (with about 90 seconds exposure).

btw eb, I have always wetted the screen, and after it sits a bit, gently rubbed it and that really seems to start the unexposed emulsion removal process, and I think I get a shorter rinse-out time. Just an old habit.

As for the water-filled dip tank to start the process, I may be in the process of redoing my "wet room", and if I need to have my rinse-out area outside, I am planning on wetting my screens immediately after exposure to "shut down" the process  to then be able to work in regular daylight. Anyone ever do this?

[ebscreen]

Hmmm, never thought of rubbing wet screens.

I'm in the process of redoing my wet room too. I've got skylights to contend with in the main warehouse,
and I'd like to get my washout further away from my drying cabinet and exposure unit. So the idea
is expo unit- dip tank- washout booth out in main warehouse.

We'll see.

[Parker 1]

I wet the screens and let it marinate for a minute or two.  I do not feel comfortable rubbing a screen with a lot of half tones in it.  I use low pressure from a normal hose attachment then will switch to a light fan to finish it off.  I did not take any pics of the screens but here is a portion of the final printed image. 

[Frog]

Although I will say that most of my stuff is solid areas, with halftones less than 10% of the time, I am constantly reminded by experts that a properly exposed screen, (same time for bold solids as halftones) is much tougher than many would think.

[Chadwick]

I've haven't timed the process in a long time.
Vacuum blanket takes a half a minute, less/more, depending on the frame style I'm using.
I believe my burn time is still around 3 minutes.
Washout?
I always use a garden sprayer. I prefer the ones with a good range on the valve.
Pre-soaking would be awesome, but I kinda do that with the sprayer, so it's all good.
Once the image area gets loosened, you can hammer it,
but it's good to work up to it, or you can achieve undesired results.
Let's say 2 minutes for something with lots of tones?

I guess about 5-6 minutes per screen, but I'm usually doing other things at the same time, so..?
I usually expose while setting up a job on the press, or mixing ink, or whatever.
( sayin' screw it and goin for a smoke? )
 

[Get Shirts]

Can a 230 hold 65 lpi?  I'm with Frog, properly exposed screens are solid.  We won't hesitate for a minute to use the pressure washer.  Give it a shot, you should shave a minute or two without sacrificing any of the detail.

[Chadwick]

I forgot to mention..I can hold higher lpi than I should be able to on a lower mesh because of my exposing/washout
methods...hence one has to be careful at beginning of washout. That's the only reason I bring that up.

If I recall, the basic calc is:
mesh / 4.5 = recommended lpi for the rip ( which is a generalization, but a safe place to start )
So, 230 /4.5 = 51.

Having done that math, one may say no to 65lpi, but then again, I've always run higher than recommended.
Give it a try at 65 if you wish, but make sure your seps are tight.
You have to be diligent with your tone values when you push your luck, or you will quickly find the ranges that don't work right.

50lpi certainly isn't anything to balk at if the art is good.
Many use 45 on a similar mesh and it looks awesome, and is production friendly.
Heck, even 40lpi looks nice if done right.

Hope that helps some of you.