Leaving RA4 chemicals in Printo

[Matt5791]

A number of people have said it is Ok to leave RA4 chemicals in the Durst Printo RT processor I use between use - but do I need to keep them "active" or anything, or can they just sit there for week after week?

Should I be running the machine periodically?

Any advise much appreciated,

Matt

 

[stefan4u]

Dear Matt !!

This will be only OK for a day, better just over the night. Maximum for me are two days. The chemicals degrade if exposed to unlimited (room)air oxygen. The only way to overcome this, is having a regular output of prints in conjunction with the use of replenishment solutions. That way you will have a “tank turnover” of approx. half (or more) of the chemicals each week. This way you can keep your chemicals alive, this is the way professional labs do it too.

There is another trick to compensate oxidation a bit, so called additives to slow down degradation. This is mainly diethyl hydroxylamine (free base) for the developer and sodium disulphite for the blix. This is/was (never tried it) available by Kodak, probably other brands do have such stuff too.

So, If you work in “batches” and neither replenish, nor use additives and let your chemicals sit in the machine, you get into trouble after short time… Drain them and rinse the machine, look for recent post in the rcp vsn thread,
(there was a url link here which no longer exists)
Mike Wilde experiences aren’t hypothetic at all !!

Regards from Germany,
Stefan

 

[Vaughn]

We use RA chemistry in an Ilfochrome processor. I figure 5 days to be the max...and it does decrease the number of prints one can coax out of the chemicals. So before I fill the processor, I try to have several students lined up who will exhaust the chemicals in a couple days.

Vaughn

 

[frotog]

I have a couple of fujimotos. I always pull the racks at the end of a session and put down floating lids over the chem. baths. Oxidation is the enemy. Floating balls in your replenisher will help keep things fresh a little longer too. I've also found that kodak developer additive and the bleach/fix additive really do work in sustaining the life span of the two baths. But even with the restrainers and even with very high rates of replenishment due to large runs of multiple prints or when doing 20x24's I still find it necessary to dump the working chem. and start over after 10 to 14 days. This is not at all surprising seeing as how a table-top machine's chemistry baths hold one tenth the amount of chemistry of a large, floorstanding roller transport machine. The small baths oxidize a lot faster.

 

[stevewillard]

I have the Fujimoto CP51, and I use additives to reduce the oxidation. I also remove the racks from each tank and wash them down each night and then place a floating lid over each tank. With the floating lids, I can leave the chemistry in for up to three days without any serious oxidation. For longer periods, I drain the chemistry into a 2.5 gallon container with floating lids and a cover. I then fill the baths in the processor with water to keep the replenisher pumps from drying up.

The tank chemistry will store well up to 4 weeks in the containers with the floating lids with minimal oxidation. My replenishing containers also use floating lids and covers and will store replenisher up to 7 months with little oxidation.

Hope this helps...

 

[Matt5791]

Hi everyone - many thanks for the replies - very helpful indeed.

Now I know where some of my problems are coming from.........

Just to clairfy, what are the main symptoms of oxidised dev / blix?

Many thanks,

Matt

 

[Vaughn]

Your shadows have the blues, the developer resembles the muddy Mississippi, and it looks like it snowing in the bleach-fix.

Your results might differ.

Vaughn

 

[Matt5791]

Thanks very much for that - sounds familiar!

Matt

 

[Richard Harris]

Matt,
I use a printo and I wouldn't recommend keeping chemicals in it for any period.
The printo agitation system causes massive oxidation any way. I decant immediately, while still at 35 degrees in to 2500ml bottles. I then fill the tanks with water and one drip of detergent. I leave this to run for a while and then leave it in the tanks. This means I do not need to dry and clean the machine. When I wish to print again I drain the tanks, fill again to clean away the detergent and then drain and refill with the chemicals. I find that they last a long time this way and I don't need to take the tanks etc apart to clean and dry. If you find yourself bottles that you can fill to the top with the 2.5l tank capacity you can exclude any air without problems.
Good luck,
Richard.

 

[Matt5791]

Thanks for that Richard,

Matt

 

[Mick Fagan]

I too run a Durst Printo with RA4 and I drop the solutions at the end of a session. It takes no more than 8 minutes to drain into 2.5l bottles and give the tanks and roller cages a quick rinse.

I once left the unit full overnight switching off around midnight, I went back in around 0700 to fire up the bath. I started to print around 0800, noticed that there was a difference in the look of the developer (much darker I thought) and continued on from there.

At the end of that session, which was late morning, I dropped the baths and noticed quite a bit of gunk on the developer in-rollers where they had subject to air. Decided I didn't like cleaning gunk off rollers unless it was unavoidable, haven't left the unit sit overnight ever since.

When your developer is starting to go off, whether that be from exhaustion or oxidisation, you generally can see that your blacks have a blue tinge to them. No amount of filtration seems to get rid of it, time to drop the bath and load fresh chemicals.

Mick.

 

[Matt5791]

Thanks for that Mick,

Matt