Re: ¿liquid emulsions?

----- Original Message -----
From: "Ryuji Suzuki" <rs@silvergrain.org>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Sunday, February 15, 2004 10:46 AM
Subject: Re: ¿liquid emulsions?

Hello,

I'm generally a lurker, but I can help you out a little with your liquid
emulsion questions.
-------------------------------

> Does the surface temperature you apply the emulsion to matter?
-------------------------
Applying the emulsion to a warm surface allows for a smoother coating.

Although the emulsion must be warmed (not over 120 degrees) to use, it is
not a good idea to warm the emulsion more than two or three times. Heat
causes it to "turn".
------------------------------------------------
> How strongly does it adhere to the surface it is brushed onto?
------------------------------
The emulsion is quit fragile when wet. Once it is dry it is not so fragile,
but I wouldn't put my fingers on it, or lay it face down even after it is
dry.
-------------------------
What if the surface is not porous? Or is very porous?
----------------------
I've used the luiquid emulsion (Rockland Liquid as well as others) on tiles
and I learned to pour the emulsion on the porous surfaces, catching the run
off in a glass dish. Although, rough surfaces can lend a unique look to
your image if that is what you are going for.

I've used it on glazed (none porous) surfaces too, and either pour or brush
it on.

After coating the tiles, I put them in a dark enclosure with a fan (make
sure the environment is dust free) to dry.
-----------------------------------

> Are there any extra materials or equipment I will need other than a brush
a
> surface and the emulsion?
-----------------------
The emulsion needs to be heated in order to use it. It's easir for hard
surfaces if the surface can be warmed for the application of the emulsion.
I've had to clean the tiles with a mild acid solution ( a caustic soda
solution or vinegar and water), then add a "subbing layer" such as
Polyurethane or gelatin). This helps the emulsion adhere to the surface.
Make sure the subbing layer is thouroughly dry before coating the surface
with the emulsion.

Anything you use to coat the surface with the emulsion must be absolutely
clean. Liquid emulsion contaminates very easily and it is expensive, so
you want to be careful. It also ages. Even if kept in a dark place it is
ruined if not used in a reasonable amount of time.
-----------------------------

The emulsion is very light sensitive (the dryer it gets, the more light
sensitive).

I hope I helped a little.

Marilyn Dalrymple
Received on Sun Feb 15 14:05:35 2004