26% Ferric Oxalate vs. 20% Ferric Oxalate

[donbga]

Hi Everyone,

Yesterday I attempted to mix a fresh batch of a 26% solution of Ferric Oxalate. No matter what I tried I could never get all of the dry FO into solution. This was Bostick & Sullivan FO. I also used an addition of oxalic acid and EDTA - tetra.

I can make a 20% solution relatively easily.

So if I use a 20% solution how will it affected palladium printing? If I've calibrated digital negatives with 26% FO will I see a major difference in prints. I assume that there will be a reduction in emulsion speed.

Thanks,

Don Bryant

 

[jkschreiber]

Hey Don,

How hot are you mixing? Mine goes into solution fairly quickly if I start with the water at 180 F. Used to be 120 was sufficient. Reheating will not help.

- Keith

 

[donbga]

Hey Don,

How hot are you mixing? Mine goes into solution fairly quickly if I start with the water at 180 F. Used to be 120 was sufficient. Reheating will not help.

- Keith

Hi Keith,

I'm starting out with boiling water heated in the microwave, so at least 180F, so I dunno . You are right, reheating doesn't help.

Thanks,

Don

 

[Ron-san]

Hi Keith,

I'm starting out with boiling water heated in the microwave, so at least 180F, so I dunno . You are right, reheating doesn't help.

Thanks,

Don

Don-- For what it is worth, my method is to weigh out 13 grams of Bostick and Sullivan Ferric Oxalate, put it into a 50 ml bottle, and add 50 ml of water (in Seattle the tap water does just fine). Then I place it on a coffee cup warmer (small hot plate for keeping a cup of coffee warm). Occasionally I give it a vigorous shake. In about 30 to 45 minutes it gets rather warm (I can still pick up the bottle) and it all goes into solution. No problemo.
As to what would happen if you lowered the concentration to 20%, sounds like a topic ripe for experimentation.

Cheers, Ron Reeder

 

[donbga]

Don-- For what it is worth, my method is to weigh out 13 grams of Bostick and Sullivan Ferric Oxalate, put it into a 50 ml bottle, and add 50 ml of water (in Seattle the tap water does just fine). Then I place it on a coffee cup warmer (small hot plate for keeping a cup of coffee warm). Occasionally I give it a vigorous shake. In about 30 to 45 minutes it gets rather warm (I can still pick up the bottle) and it all goes into solution. No problemo.
As to what would happen if you lowered the concentration to 20%, sounds like a topic ripe for experimentation.

Cheers, Ron Reeder

Well guys I guess I'm not holding my mouth right. The guys at Bostick & Sullivan suggested that a 20% solution should be easy to dissolve.

Thanks,

Don

 

[donbga]

Hi Everyone,

Yesterday I attempted to mix a fresh batch of a 26% solution of Ferric Oxalate. No matter what I tried I could never get all of the dry FO into solution.

Problem resolved. The issue was caused by user error.

1) Raised water temp to boiling.
2) Used reading glasses to measure water volume correctly.

All of the FO goes into solution within about an hour, most dissolves within minutes.

Thanks everyone,

Don Bryant