PDA

View Full Version : storage of finished emulsion



rmazzullo
04-06-2007, 09:13 PM
Hello PE,

Is there a "shelf life" to a batch of finished emulsion? What would be the best way of storing a batch of finished emulsion for later use without damaging it?

Thanks,

Bob Mazzullo

Photo Engineer
04-06-2007, 09:55 PM
If the emulsion is not stabilzed with Thymol to prevent the growth of bacteria and mold, then its life is very short indeed.

If stabilzed, it will last quite a while. I have had the raw emulsions that I make last at least 6 months in a refrigerator.

But, a 'finished' emulsion implies to me that you have added sulfur or sufur + gold senstitzation. We usually sensitized emulsions this way prior to use, and added stabilzers as the raw emulsion keeping goes down after sulfur or sulfur + gold addition.

See my previous posts on this process.

PE

hrst
09-05-2010, 09:35 PM
Browsing around some old posts to rehearse all this information...

Indeed, the emulsions don't keep too well without thymol.

However, I would like to ask if I can stabilize the emulsion with thymol just after the noodle wash, that is, BEFORE the finishing steps---does it affect the sulfur(+gold) sensitization step? Or should I make the sulfur sensitization first and then add thymol as the last addition before storing for coating?

Photo Engineer
09-05-2010, 10:40 PM
You can store both before and after the sulfur or sulfur + gold sensitization steps. We did both at EK depending on time of day and schedule. I have now kept an emulsion with thymol for 1 year. It will vary from emulsion to emulsion.

PE

hrst
09-05-2010, 10:45 PM
Thank you again for your help!

alexhill
09-08-2010, 08:49 PM
Once again, awesome stuff. I've got a batch that has been sitting in a fridge for 2 months that was treated with Thymol.

Photo Engineer
09-08-2010, 09:36 PM
I now have a sample of a better preservative (actually two of them) that might help. Unfortunately, it was preserved with copper which hurts emulsions.

PE