Trying RA-4 again

[arden_howell]

Using a Cibacrome 8x10 manual drum and roller with Besler RA-4AT

chemistry, what is an economical replenishment sequence that will

still produce consistent (ha ha) quality results? Besler says that 1

liter of chemistry will produce about 38 8x10 prints. Of course, I am

not married to that number, but would like to see if anyone is doing

it. Any tips greatly appreciated. In the past, I have found that it

has taken 2 1/2 oz. a shot to process evenly. I would also

appreciate any advice on storage of the chemicals. I have tried the

accordion type bottles which tend to gradually expand or bend

themselves into some kind of exotic shape. Even the unmixed but open

concentrates seem to have a very short lifespan.

[don_feinberg2]

I have done a fair amount (well over a thousand prints) of RA4 in the last year or two. I think I've developed a couple of ways of getting reasonably consistent results while not using "tons" of chemistry.

 

My "replenishment" scheme is this:

 

(1) When using chemicals "fresh from the bottle", that is, the first print in a session, process for 1 min in both developer and blix.

 

(2) I use a standard, but weak, stop. Boric acid crystals, 30 g/liter, for 30 seconds.

 

(3) For prints after the first, I replenish about 1 oz of both developer and blix for each print, by pounring off about 1 oz and adding a new 1 oz each.

 

(4) In "replenished" chemistry, I process for 1 min, 15 sec. in both developer and blix (assuming 95.0 degrees F!).

 

(5) I find that the blix is very stable. It's the developer that's the problem. I have charts I've made for each manufacturer's kit giving the proportions of developer components per liter of working developer. I only mix one liter of developer at a time. I use what I can, and mix as I go. Once mixed, the developer will last at most a week or so.

 

If more than a week or so has gone by, I discard the old portion of the developer and mix up a new liter. I have had no problem with the stability of the components, at least over periods of several months (in a dark/cool darkroom).

 

(6) I do use a reasonably sophisticated temperature control scheme. My process temperatures are pretty consistent for the entire process. I consistently maintain 0.1 to 0.2 degree F in temperature stability over the process, so temperature isn't a "variable" I worry about.

 

 

Hope this helps...

[boris_krivoruk2]

That's what I do: I use RA-4 one-shot. But I don't discard it. Once I am done with fresh developer, I double development time and use the same developer second time. Although I don't store used developer for more than couple of hours. I run a test prior to switching to used developer, but it's pretty consistent.

[boris_krivoruk2]

Just realized I made an error in my last message. I don't double development time in used developer, I increase it by 50%. Development in fresh developer is 1 min, in used 1min 30sec.