Re: żliquid emulsions?

From: John Prokos <john@prokosphoto.com>
Subject: .AN?liquid emulsions?
Date: Sun, 15 Feb 2004 23:01:52 +0545

> Does anyone here have experience with Rockland Liquid Emulsions?

I don't have experience with this product. I make my own from scratch,
so below is based on my batches, not on that product, though my
batches are pretty standard silver gelatin material.

> Does the surface temperature you apply the emulsion to matter? I would
> imagine it should be approximately the same as the emulsion if possible
> rightŠ

That is probably ideal to get most even result. If the surface is
cooler, viscosity may go up as you work the coating.

> How strongly does it adhere to the surface it is brushed onto? What
> if the surface is not porous? Or is very porous?

Paper, cloth etc. -- no problem. Suede leather -- small dripped
emulsion sticked there without cleaning or brushing on the surface
(though if you want to use leather, I'd clean the surface and brush.)

Glass -- needs good cleaning, and I'd use surfactant (PhotoFlo, Triton
X-100, etc.), hardener (glutaraldehyde), plasticizer (glycerol aka
glycerin, triethylene glycol). As far as I know, Kate does this way
except with formaldehyde. After coating, chill setting at lowest
temperature you can get easily (but without freezing) works the best.
I put coated glass in fridge for several minutes, then take them out
for drying at room temperature.

For paper and other absorbent material, it's ok to dilute the emulsion
a bit. But for glass and other smooth surfaces, I'd use thickest
possible emulsion.

> Can I use a toner like Kodak Selenium Toner on the emulsion?

Yes. Make sure to fix it very well, especially if your coating is
thick.

> Are there any extra materials or equipment I will need other than a brush a
> surface and the emulsion?

Anything you can use to do water jacket at 35-40C. I use a brown
glass dish to hold emulsion, and put this in a shallow water bath on a
heating surface, so that I can use 4-inch brush easily.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)