Ferric Oxalate Nightmares.

[jimgalli]

I just want to throw my experiences out there to see if they are extremely abnormal or about the same as what other folks are seeing regarding mixing this troublesome goo.

Here's my "normal" procedure. I use a 1 cup Pyrex graduate to mix in. This gives plenty of room for elaborate stirring without spilling. I'm trying to make a 27% solution so it's 15 grams ferric oxalate powder, 1 gram Oxalic acid, 55ml distilled H2O. I make a "water bath" in a 1 quart Pyrex and put the 1 cup pyrex in the water bath. I heat the water bath with one of those coil things that has an electric element inside for re-heating coffee. When my distilled water gets steamy (around 200+ or - degrees F I add the Feric Oxalate. I stir a bit, then I add the Oxalic acid. Then I stir for about 1 1/2 hours. It's a PITA.

What I end up with is something like a 20% disolved solution which is useable. I have sludge that never ever does go into solution. I let it settle at the bottom of the bottle and try not to worry about it.

When I print, I have to use far more FO than the "recipes" call for. For instance an 8X10 would be 20 drops FO to 13 drops Pd Pt etc.

What am I doing wrong? What are you all experiencing? This stuff seems to be a nightmare to me.

BTW the powder I'm using was purchased from Artcraft Chemicals about 6 years ago, has been stored properly, and has always reacted just as it does now. I have no reason to believe it was a bad product.

[Ray Bidegain]

You are having a hard time!

It sounds like you have the amounts correct, and the oxalic acid is supposed to make the mixing easier. I do not use the acid as a rule. I mix mine by putting the hot water in a graduated cylinder I have that has a stopper, I add the FO put on the lid and shake it for 30 seconds, let it rest 5 min. and shake it again. If it is still not ready to go I put the whole thing in a beaker filled with hot tap water and let it sit for 5 more min. then it is done. I never have sludge.

My best guess is that you need some new FO, I get mine from Bostick & Sullivan.


Ray Bidegain

[jimgalli]

Thanks Ray. That is what I wanted to hear. Guess I'll go shopping.

[glbeas]

Does the mineral content of the water affect the dissolving rate? Seems to me there are quite a few ions that will make an insoluable sludge with the ferric ion.

[jimgalli]

Does the mineral content of the water affect the dissolving rate? Seems to me there are quite a few ions that will make an insoluable sludge with the ferric ion.

I boiled all the minerals out of it. Distilled. jg

[glbeas]

I boiled all the minerals out of it. Distilled. jg

I take it then the recommendation is to use distilled water always when making up this solution. Hopefully you didn't get a jug of spring water by mistake for your darkroom, I've almost made that mistake myself.

[photo8x10]

I've just finished to read your reply about to make a solution 1, I would like to try to make it, and I have this questions.:
1) What temperature should be distilled water? (the best to dissolve powder chemical, I read more and less 120/150 degrees F)
I saw in internet some receipe about solution 1 with also EDTA
2)Do you raccomand it? and Is it helps shelf life?
3)How long will it take me to stir the solution?(the right time to finish the solution)

Maybe are stupid questions but I'm new in this kind of printing, and so far I used to use Bostick and Sullivan solutions(ready to use) but like my silver print (AZO) I want to make, if possible, solutions by myself.

Thanks

Stefano Germi
Italy

[jimgalli]

I've just finished to read your reply about to make a solution 1, I would like to try to make it, and I have this questions.:
1) What temperature should be distilled water? (the best to dissolve powder chemical, I read more and less 120/150 degrees F)
I saw in internet some receipe about solution 1 with also EDTA
2)Do you raccomand it? and Is it helps shelf life?
3)How long will it take me to stir the solution?(the right time to finish the solution)

Maybe are stupid questions but I'm new in this kind of printing, and so far I used to use Bostick and Sullivan solutions(ready to use) but like my silver print (AZO) I want to make, if possible, solutions by myself.

Thanks

Stefano Germi
Italy

Stefano, my experience is limited of course. But even though the literature says 140 degrees I have found out it really doesn't mix well until about 200 degrees. Other thing I have found is that the EDTA did not help. In fact the one batch I mixed with EDTA to try to help it was no good at all. I had to pour it out. Like I say though my experience is limited and other folks are having far less problems. Hopeful that your Bostick chems are nicer to you.

[magic823]

Heat and time.

BTW, I make my own Ferric Oxalate. Anybody want me to post the "recipe" for making your own?

Steve

[Photo Engineer]

I've been thinking this over for a few days. Here are the only things that occur to me.

1. Bad Ferric oxalate. It is easy to mess this up IIRC.

2. Bad oxalic acid. If there is sodium oxalate in this it would be bad. If it is not oxalic acid, it would be bad.

3. There are not enough 'hard' ions in even tap water to give you that much sludge so the water does not appear to be the problem whatever the source.

Heating oxalate salts too much in the dry state can lead to decomposition sometimes. I cannot find Ferric Oxalate in my handbook, so I cannot pass along any information other than recollection.

PE