RA4 Printing chemicals failing

[GoodOldNorm]

How can you tell when your chemicals particularly the developer is getting tired? I have noticed that the last print I made looks a little muddy and dull, is it time to use fresh chemicals? I have processed about 30 sheets of 10x12 paper. Thanks in advance for your replies.

[paulc]

You could be hitting the limits of capacity. Don't know who's chemicals you are using, but if you use the Kodak data sheet as a reference: J39.pdf, it has this to say:

Solution Capacity
You can reuse the chemicals without increasing the time in
the developer for subsequent processes. The recommended
number of 8 x 10-inch (20.3 x 25.4 cm) prints is 15 per quart
(946 mL) or 16 per litre (33.8 fl oz). In some noncritical
applications, you may be able to process up to 40 prints.
However, do not use developer that has been in an open tray
for more than 4 hours.

[GoodOldNorm]

Originally Posted by paulc

You could be hitting the limits of capacity. Don't know who's chemicals you are using, but if you use the Kodak data sheet as a reference: J39.pdf, it has this to say:

I am using the Tetenal RA4 Photopearls kit in a nova dip/dunk tank the instructions say 2.5 ltrs should do 5m2. So you are correct I may be reaching the chemicals capacity. The chemicals have been in the tank for 2 weeks now with the tubes in the slots and with cling film over the top.

I have read elsewhere that when the developer starts to become exhausted the blacks look more blue. I have not noticed this yet, just an overall lack of bright colours.

[GoodOldNorm]

I have had the darkroom door open to the elements all day, when I checked the temperature of my chemicals they were at 29 degrees not 35. So I turned up the temp control on the nova slot processor switched an oil filled radiator on shut the door and let everything warm up. Went back into the darkroom stirred up the chemicals with a piece of plastic rod(wiping it between each bath). Checked the temperature was at 35 degrees, then did a print to match the first print I made with this batch of chemicals. All OK.

[John King]

The general replenshment rate for RA4 is 10cc for every 80sq ins (10x8 sheet.) and more or less pro rate for larger or smaller sheets.

If you use a Nova processor, with adequate replenishment as above, the developer will last almost indefinitely. I use Kodak Ektacolor and have known it last 18 months or more. I only changed it when I drained the tank to clean it out.

The Blix will go off and start to smell even with replenishment, 6 months at most then it is due to be replaced.

[GoodOldNorm]

Originally Posted by John King

The general replenshment rate for RA4 is 10cc for every 80sq ins (10x8 sheet.) and more or less pro rate for larger or smaller sheets.

.

The Blix will go off and start to smell even with replenishment, 6 months at most then it is due to be replaced.

Hello John, I am using Tetenal Photopearls it has packets to mix two batches of 2.5 liters. If I mix 2.5 litres of dev and blix and put it in my Nova slot processor can I mix the other 2.5 liters and use it to replenish?
If so how much would I need to add to the dev and blix to keep it active?
Is this method more economical than just dumping the first batch and starting again using the fresh chemicals.

[Mike O'Pray]

If I recall correctly, Norm, Photopearls are literally chemicals in solid form as "pearls" and always struck me as a good idea in that while they remain pearls their life is almost indefinite. A bit like unopened powder chemicals except that even better I don't think they need to be in an airtight container and you can even make up small quantities at a time but I may be wrong about that

However I haven't seen these being sold for many years. Were these bought several years ago or is Tetenal still making them and if so where are they sold?

Thanks

Mike

[GoodOldNorm]

Originally Posted by Mike O'Pray

If I recall correctly, Norm, Photopearls are literally chemicals in solid form as "pearls" and always struck me as a good idea in that while they remain pearls their life is almost indefinite. A bit like unopened powder chemicals except that even better I don't think they need to be in an airtight container and you can even make up small quantities at a time but I may be wrong about that

However I haven't seen these being sold for many years. Were these bought several years ago or is Tetenal still making them and if so where are they sold?

Thanks

Mike

You are correct about them being old they have been in my cupboard at least 5-6 years they were initially bought from Morco photographic. The chemicals are a rough powder that comes in sealed bags they seem to last for ages, I have only seen the tetenal liquid colourtec kits for sale recently.

[Mike O'Pray]

Thanks, Norm. I was afraid you'd say that. Pity

Mike

[GoodOldNorm]

Found out why my developer failed early, after giving it a good stir and getting it up to temperature I did a test print and every thing looked ok. Things soon started to go wrong so I dumped all the chemicals, when draining the water bath chambers I noticed the water in the chamber next to the developer slot felt slimy and was off colour. So I filled the developer slot with water and added some green food dye. I filled the water chamber half way up the site window in the end of the unit and marked it with a piece of tape. After it had stood over night the water level in the water bath chamber was up and the water was tinged with the food dye. Bugger I have a leak on the developer chamber