[Frameworks] Liquid Light onto clear 16mm - any tips?

[Robert Schaller]

Very interesting tips, Scott and Nicky, and I'm very happy to hear such interest in coating one's own emulsion!  My experience has been that it is somewhat unpredictable, and highly influenced by temperature and humidity when coating (you want warm humid conditions), but as Jason points out, mostly I've just used a large (and seemingly endlessly renewed) supply of flashed B+W print stock, which already has a subbing layer and gelatin (and which needs to be used anyway!).  Since it generally works (and there's more to say about it), I've never spent the time to look further.

However, this doesn't address coating raw plastic.  I've found that sometimes it works, and sometimes it doesn't -- that's not a very scientific observation!.  The patent that Nicky refers to uses vinylidene chloride, aka 1,1-Dichloroethane, which is a volatile neurotoxin, one which I would like to avoid; plus, the formula is not disclosed definitively, and it involves a number of chemicals that would not normally be in a darkroom's formulary.  Scott's suggestion, on the other hand, involves only one chemical, and though it is also not healthy, it seems primarily to be corrosive, and so to be manageable.

As sort of an aside, I have to say that artists should be very careful to use hazardous chemicals.  Many photo-processes use chemicals that are really dangerous, like Potassium Dichromate which is a probable carcinogen (remember the movie "Erin Brokavitch?"  The evil pollution at the center of the whole movie was the same form of chromium as in Potassium Dichromate...) .  With proper lab procedure, in a proper lab, one can use things like this, but NOT in the bathroom!  I exhort my peers in the artist filmmaking world, read the MSDS sheets, and don't get this stuff mixed up in your household stuff, laundry or otherwise!

That said, Scott, have you (or anyone else) ever used 3-Aminopropyltriethoxysilane for coating film?  I found it here:

http://www.polysciences.com/Catalog/Department/Product/98/categoryid--72/productid--150/

which says

"Reacts with glass and other silaceous surfaces creating aminopropyl substituents. Surfaces so modified have enhanced adhesion properties and can adsorb anionic matter."

This sounds like it is an adherent for glass ( and other silica materials), but I don't see how this applies to plastic, acetate or otherwise.

Finding a good sub for acetate or polyester would be great, and I'm very interested to hear any thoughts about it!  Has anyone translated Nicky's patent into a usable recipe?

--Robert Schaller
 
On May 31, 2013, at 8:37 AM, Scott Dorsey wrote:

> What temperature are you developing at?  Have you tried moving down to 65F
> or so?
> 
> Are you using a tank or roller transport?
> 
> If you're using a polyester base, try an acetate base instead, which has
> better adhesion.
> 
> Commercial emulsions use an adhesive layer.  You could try making a really
> dilute (1/2 percent) solution of 3-amino-propyltriethoxysilane in alcohol
> and coating with that.  Eastman Chemicals should have it, or you could ask
> Photographer's Formulary.
> --scott
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