[Dmounce]

hello to all

My problem is washing out fine lines after exposure. I used an exposure calculator to expose properly for fine lines, but they won't come out and look clean. I end up washing for 4 to 5 minutes and my emulsion withers. I use my shower head with a fair stream of water to washout. Am I in need of a pressure washer?

thanks,
Dusty Cakes

 

[out da box]

You may try a garden hose with a nozzle attachment and about 5-10% less exposure time so the samll lines wont close up prematurely during burning.

 

[Greenpaw]

I have a similar problem. Does the exposed emulsion still deteriorate during a long wash out? I am using a white 220 mesh for a picture with sketch style shading, looks like it was done with a ballpoint pen. I am exposing for about 40 minutes with a custom made unit with about 15 pounds of pressure to ensure contact of the negative. Using Diazo emulsion in a very very thin and even layer on both sides. I ran the negative through photoshop to clean up the levels and ensure it is black.

Here are my questions:

Will a longer washout under weak pressure be better to ensure detail than a quick high pressure wash?
Is 220 mesh too low for this amount of detail? If so what is the optimum and max mesh size for speedball water based inks?(color and white)
Is thin application of emulsion better or worse than a thick emulsion application to preserve fine detail?
Or should I just stop worrying about this and increase my exposure time until it works?

 

[tman07]

you should be able to hold just about any line or dot with a 220 mesh

the less emulsion the better - one pass each side with a good emulsion

a properly exposed screen can withstand a very vigorous washout

a good quality film positive is important too.

hope that helps some

 

[beanie357]

Too long washout.
Unless using water base type emulsion.
Suggest hose nozzle. Rework your exposure using a calculator.
We se a pressure washer and Qtx and washout is under a minute.
Should not take that long with a nozzle as you are having to do.

 

[Greenpaw]

I figured out my problem. The object I was using to put pressure on my screen was actually bending the fiberglass under it and actually worsening the gap.
I now use a plastic shopping bag with some catlitter and it works remarkably well