Problems bleaching Ilford papers

[larfe]

Hello,

I'm getting random dots on Ilford MGIV and MGWT when bleaching for second pass lith. It comes in the form of dots and only after the print has been in the bleach for around 1.30 minutes.
The bleach is made of 30g pot. ferri. and 10g pot. bromide + 1000 water diluted at 1:1. I'm wondering if I should use a stronger dilution instead

The other day I didn't get the spots and I can't figure out, I'm wondering if the prints didn't stay in the bleach as long... Or could it be that the prints have to be dried after first wash, I've heard that it helps settle the print (for toning).

Never had problems bleaching foma papers.

I've attached a pictures of the spots/dots.

Thanks in advance

 

[paul_c5x4]

The bleach is made of 30g pot. ferri. and 10g pot. bromide + 1000 water diluted at 1:1.

My bleach is usually 5g pot.ferri, 5g pot.bromide in 1L of water. Bleaching usually take two to five minutes depending on how far I want to go.

 

[gzinsel]

contamination? did you wash sufficiently? before bleaching?

 

[larfe]

Hi,

the prints were washed for 2 hours to make sure that all the fixer was removed.

Thank you

 

[Ian Grant]

It may be there before you're toning, are you using a two bath fixing regime, if not you should do, and use a wash aid 1 or 2% Sodium Sulphite solution works well. 2 hours washing is too long.

While I use a bleach which is equal parts Ferricyanide and Bromide (like Paul) there are bleaches that use a lower proportion of Bromde than you are using so that shouldn't be an issue.

Ian

 

[larfe]

This is for second pass lith not toning. The spots appear when the print has been in the bleach for around 1.30 minutes.

I've just tried this morning with some throw away prints, one on ilford art 300 and the other on rc paper of some sort, and there were no spots to speak of.

This happens with MGIV and MGWT.

 

[Ian Grant]

This is for second pass lith not toning. The spots appear when the print has been in the bleach for around 1.30 minutes.

I've just tried this morning with some throw away prints, one on ilford art 300 and the other on rc paper of some sort, and there were no spots to speak of.

This happens with MGIV and MGWT.

It doesn't matter what process you're using after as the bleach is a homogeneous solution so you need to be looking at the prior processing, that's where the issue originates.

My guess would be poor fixing leaving traces of semi-soluble silver-thiosulphate complexes in the paper, no amount of wash aid or washing will remove them. This is far more of an issue with FB papers as the complexes bind with the cellulose in the paper base. FB papers need low levels of silver in the fixer which is why 2 bath fixing is the best way of ensuring there's no issues in toning or long time permanence.

Another issue is the 2 hour washing may be removing optical brighteners in the paper patchily.

Ian

 

[larfe]

Thanks Ian. That would make sense indeed.

I will try this in my next session an report back.

 

[larfe]

Well well,

I've changed everything fresh batches of everything and am now also using 2 fixer bath in alkaline fix.

It's solved almost everything, except the wash aid. When using fotospeed wa50 wash aid, on drying the prints will have some sort of residue or stains which become more apparent when viewing the print at an angle.
It's ruined quite a few prints, there's hardly any info on the web about wa50. I tried rewashing dried prints without success.

I should have bought the kodak hca instead, but if anyone could chime in with a way to rescue the ruined prints would be much appreciated.

 

[larfe]

Looks like I might have found the problem.

The fotospeed wash aid would appear not to contain something to prevent the formation of calcium scum.

http://www.digitaltruth.com/products/msds/Fotospeed_WA50_Wash_Aid_MSDS.pdf

That would explain why the it looks like a white deposit.

Anyone knows how to removes this from a print?

 

[Ian Grant]

Acetic acid (stop bath) will remove calcium scum.

Ian