Re: temperaprint & foaming

Gord i think the problem is that you are overloading the roller with
emulsion and that on the final pass over the yupo with the roller the hand
should just support the roller but not apply any pressure I am sure that
Some of our experienced Temperaprinters on this list could supply a
better.explaination Dennis Klinker
----- Original Message -----
From: "Gordon J. Holtslander" <holtsg@duke.usask.ca>
To: <alt-photo-process-l@usask.ca>
Sent: Monday, February 13, 2006 6:15 PM
Subject: temperaprint & foaming

> Hi:
>
> I continue to fiddle with tempera printing - still not happy with coating.
>
> I've tried using a brush, roller, and paint pads - but still get a very
> inconsistent coating.
>
> Get the most consistent coating using a roller, but application with a
> roller creates lots of tiny bubbles.
>
> Read that the addition of salt reduces foaming and bubbling. Added a
> pinch of salt to the last tempera mix. It appeared not to foam as much.
>
> I wanted to see what a brush coating would do - no bubbling, and was able
> to put on a very thick coating. So thick that it would not bind to the
> yupo, or the addition of salt prevented proper hardening.
>
> Didn't have time to do a roller coating though.
>
> Read more about antifoaming agents. Looks like Dimethylpolysiloxane is a
> commonly used food grade antifoaming agent. Its seems to be a suspension
> of very fine silicone particles that alter the surface tension so that
> foam bubbles can not form.
>
> Does anyone have experience with any antifoaming agents?
>
> Gord
>
> ---------------------------------------------------------
> Gordon J. Holtslander Dept. of Biology
> holtsg@duke.usask.ca 112 Science Place
> http://duke.usask.ca/~holtsg University of Saskatchewan
> Tel (306) 966-4433 Saskatoon, Saskatchewan
> Fax (306) 966-4461 Canada S7N 5E2
> ---------------------------------------------------------
Received on Mon Feb 13 14:37:04 2006