HCA agitation?

I've never seen this mentioned anywhere- HCA is used for 1-2mins. But do u agitate continously or every 30 secs like dev and fixer? TIA

ez

There have been many detailed studies made which all indicate that:

For films, intermediate agitation across the processing sequence is the most effective
For prints, continuous agitation across the processing sequence is the most effective

For film, I do not use HCA so I can't comment other than my tests show that using the Ilford washing sequence (with the modification of taking the film out of the tank and placing in a jug of water whilst I thoroughly clean the tank) before proceeding to wash produces archival quality negatives,

For paper, I use continuous agitation across the processing sequence and have found this to be consistently the most effective.

Best,

David
www.dsallen.de

Dear ez,

Either will work fine.

Neal Wydra

I've read somewhere:

For film, continuous agitation for the first 30 seconds, intermittent agitation every 30 seconds following for total of 2 minutes.

For paper, I gently rock the tray for a bit and make sure the paper is submerged for 3 minutes.

I agitate continuously for the fist 30 and then once every 30 seconds for 2 minutes.

I do what Brian does - I doubt it's really that much of an issue, but it seems to me that good agitation will make the HCA do its job better.

Continuous agitation seems unnecessary - and I like to check my rinse water temperature during some of the stand portions of the HCA step - but continuous agitation certainly won't hurt.

One other option is to use an alkaline fixer. Combined with a running water stop (instead of actual stop bath), this makes for an all-alkaline process with a pretty short wash time. 5 minutes is reportedly enough, although I wash 15 minutes for peace of mind.

Thanks for the tips! From what i've read, u don't use HCA for paper so never done it. U guys do?

Much more important for paper. Not really necessary for film but does no harm. Pretty much essential for FB paper, not needed at all for RC.

According to some data, for FB (Fiber) paper, you could do HCA for 3 minutes and wash for 30 minutes OR you could wash for 60 minutes will achieve the same amount of effect. My understanding is, HCA makes the component of fixer more soluble to water so it easily washes off.

Same for film. You could HCA and wash for 5 minutes or just wash for 30 minutes.

I store fixed but unwashed prints in a plain water bath, then at the end of a printing session mix up some sodium sulfite HCA and treat the entire batch at once. I always worry that the HCA might not get between the sheets, so to speak, with normal agitation. So I continually move prints from the bottom to the top of the stack throughout the 3 minute time period. Maybe unnecessary, but as others have said, it won't hurt.

From Kodak's J109 (X-Tol datasheet):

"Hypo Clearing Agent - 1 to 2 minutes - Agitate continuously for the first 30 seconds and at 30-second intervals after that."

ezwriter said:

Thanks for the tips! From what i've read, u don't use HCA for paper so never done it. U guys do?

Click to expand...

HCA isn't useful for RC paper, but is for fibre based paper.

And with respect to film, it helps shorten wash times, and ensure complete washing, but no HCA and a longer wash regime works well too.

See the old Photo Techniques article "Mysteries of the Vortex." HCA should be considered essential not optional for a good wash with fiber based papers:

Archived on FADU.

Part 1:

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=296

Part 2:

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=344

Roger Cole said:

See the old Photo Techniques article "Mysteries of the Vortex." HCA should be considered essential not optional for a good wash with fiber based papers:

Archived on FADU.

Part 1:

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=296

Part 2:

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=344

Click to expand...

Precisely!!! - we do not need advice such as 'it wont hurt", etc as we have the research available that clearly shows the importance of thorough working practice and the important role that HCA plays in good washing technique.

Martin undertook probably the most thorough research into FB washing and, along many other studies, it is TOTALLY clear that HCA is a must for anyone wanting to produce finely crafted archival quality prints. Constant agitation in HCA is also a must as is careful technique throughout.

Also, the idea that HCA is merely a step that, for convenience, reduces washing time is also misguided because:

a) Many people's wash water is not at 20 degrees

b) The majority of archival washers are not as effective as the manufacturers claim

c) The chemical process of removing the fixer can not be thoroughly achieved purely through extended washing

For those of us who live in countries with water meters, it is also useful to curtail washing times as much as is possible whilst still reaching the highest levels of archival standards. For films this means using the Ilford system (takes approximately 5 minutes max) and for prints this means efficient use of HCA plus adequate washing in an efficient archival washer.

Best,

David
www.dsallen.de

My "cold" water in the summer is considerably warmer than 20C. In the winter I adjust to temperature. But I also, if washing prints larger than 8x10, use successive soaks in changes of fresh water, something that Martin also showed to be remarkably effective and sparing of water, if rather annoying to do.

I've never owned an archival washer. I may some day, but only for convenience. A tray siphon works very well for a few prints. So does soaking in successive changes of fresh water. It has been objectively studied and tested, as David says. Read the research, or continue to guess and work by Internet rumor.

thanks! i've only been printing RC paper so thats why i didnt use it. I notice on my own wall notes i wrote "HCA= NOT for RC" duh!

ezwriter said:

thanks! i've only been printing RC paper so thats why i didnt use it. I notice on my own wall notes i wrote "HCA= NOT for RC" duh!

Click to expand...

Just for the record, it won't harm RC paper, but because of its plastic coating, RC doesn't absorb fixer very much and a relatively short wash will clean it up perfectly adequately. HCA doesn't improve things enough to be worth the bother.

With fibre paper, things are completely different and HCA is well worth using.