Acrylic ferrotyping: emulsion flecks off?

[Michel Hardy-Vallée]

So I tried to ferrotype prints of this photograph: https://www.photrio.com/forum/media/by-the-old-mill.64884/

I bought a nice big plate of acrylic at the hardware store, and cleaned it with Windex. However, I'm seeing some slight texture in the emulsion, and I don't know if it's because of any residue on my plate, or a function of heat/drying time. Here's a closeup. The big white part is the reflection of the window, and the flecks I'm talking about are the pits just above.



I let the print dry in my garage which is around 20C, so it's pretty slow (took about 24h), humidity around 60%. Paper is Ilford FB Multigrade.

I would say that overall the result is nice because you get this super-shiny finish that I did not even believe was possible on FB, but I'm concerned about polishing off these slight defects.

 

[Lachlan Young]

I have seen similar effects with glass - though I think I attributed it to dust on the surface (it was purely a proof of concept I was doing & didn't clean the glass beforehand). Acrylic, if you don't clean it with anti-static cleaner, will quite happily suck dust out of the air quite spectacularly...

 

[Fraunhofer]

Dust. I gave up on ferrotyping pretty much because I could not get rid of it. I have a relatively high humidity dark room and no dust issues in any other part of the process. Seems very fine dust can cause this.

 

[Michel Hardy-Vallée]

Thanks for the answers. I was also thinking about small particles in water.

I think I will do another try using a final rinse in distilled water with a drop of photo-flo, just for the heck of it.

 

[Lachlan Young]

Thanks for the answers. I was also thinking about small particles in water.

I think I will do another try using a final rinse in distilled water with a drop of photo-flo, just for the heck of it.

From recollection, Tetenal Mirasol wetting agent has instructions for using it for final rinsing before ferrotyping - I think it's used about 10x strength (eg 1+40 rather than 1+400) compared to use as wetting agent.

 

[Michel Hardy-Vallée]

From recollection, Tetenal Mirasol wetting agent has instructions for using it for final rinsing before ferrotyping - I think it's used about 10x strength (eg 1+40 rather than 1+400) compared to use as wetting agent.

Indeed, that's what I found with a quick Google. Some other thread on Photrio mentioned using regular strength Photo-Flo, so I'll try that first, and increase concentration if needed.

 

[Lachlan Young]

Indeed, that's what I found with a quick Google. Some other thread on Photrio mentioned using regular strength Photo-Flo, so I'll try that first, and increase concentration if needed.

Given that some of these surfactants are known to cause gelatin to swell (hence the use of some as development accelerators in emulsions/ processes), it does make sense for ferrotyping.