Replenishment?

[robert_davis2]

I've got a bunch of RA-4 chemicals that came along with the C-41 stuff

I got. Unlike the kit I'm using this stuff is designed for

replenishment. Do I just draw out X milliliters for every square metre

of paper I've processed and replace it with fresh chemicals? Is it

that simple? I've been doing that for film bleach and fixer and it

seems to be working just fine.

[rowland_mowrey]

Robert;

 

No, it isn't that simple.

 

The developer gradually accumulates chemicals given off by development, and the developer 'seasons' in. The replenisher is intended to match the seasoned developer solution.

 

So, a developer has a slightly different formula before use than after use. The replenisher has a formula similar to developer after use. So, taking out developer and replacing it with developer is not exactly correct. It should be replaced by replenisher.

 

With bleach and fix, the differences are not that significant so it makes little difference.

 

Under normal circumstances, you probably don't have to worry about it on the scale you are using the processes, but in large labs, the practice you describe will gradually cause a drift in the results.

 

Ron Mowrey

[robert_davis2]

Thanks. If I understand the document I downloaded from Fuji. The RA-4 developer is in two parts. A starter and a replenisher. To make the intial seasoned tank I add some starter to some replenisher. From then on I just use replenisher I guess.

 

If I remember right the C-41 fixer and Bleach the replenisher is just undiluted concentrate. The same stuff is used for everything with no starter.

[rowland_mowrey]

You are essentially correct.

 

The starter makes developer look like seansoned developer. It alters the balance of the developer to make it look used.

 

Starter is only used for developers.

 

The other solutions just add what you lose through carryout and exhaustion by adding more of the original solution in slightly different concentraion.

 

Good luck to you.

 

Ron Mowrey