Chrome Alum

[kevin klein]

What is the usual preportion of 5% CA to the gelatin? ml of CA : gm of gel.

 

[Photo Engineer]

I use 10% Chrome Alum in water. I use about 5 ml of that to 100 - 200 ml of emulsion at 10% gelatin content. This is best used on glass plates.

PE

 

[Domingo A. Siliceo]

Could I use Potassium Alum (powdered) instead Chrome Alum as the hardener? If so, what should be the proportion for the gelatin? I'll coat some glass plates with Foma liquid emulsion.

Thanks.

 

[Photo Engineer]

Potassium Alum will harden, but very poorly. It can be released in the developer to remove the hardening effect, and it can form a white sludge in the coating.

PE

 

[Domingo A. Siliceo]

Potassium Alum will harden, but very poorly. It can be released in the developer to remove the hardening effect, and it can form a white sludge in the coating.

PE

understood. Thanks.