Flow rate for Gravity Works film washer

[David Brown]

I just scored another Craigslist haul, and the "prize" was a Gravity Works 4x5 film washer. It needed a new hose, but that was easy enough.

Those of you that have/had one, what is a good flow rate? I have been using a Watair washer at a flow rate that just causes bubbles. (We're taking roll film on reels here.) When I turn the water on to the same rate as I had to the Watair, it takes the GW about 2 minutes to complete a cycle of fill and dump. Sound about right?

Thanks.

 

[nsurit]

I use the same washer for both my roll film and with the basket 4X5 and two minutes seems a bit slow to me. Bill Barber

 

[David Brown]

Yeah, Bill, that was actually my thought, too. I guess the follow-up question is: how many cycles is sufficient to wash the film?

 

[nsurit]

Now we are getting into science and belief. I believe 10 minutes in my filtered rainwater with an exchange about every 45 seconds is enough. Not sure what science wants me to do. Don't own the destruction manual. BB

 

[David Brown]

Now we are getting into science and belief. I believe 10 minutes in my filtered rainwater with an exchange about every 45 seconds is enough. Not sure what science wants me to do. Don't own the destruction manual. BB

Yep. afraid so.

I've used a Watair type washer for decades, so my "belief" is that they are effective, based on all the perfectly good negatives I still have. I use the Ilford method when the tap water gets too cold (rare) or too hot (alas, not so rare lately) to use running water.

I also know that you can wash film in a coffee can or similar container that has holes punched along the bottom edge, where you adjust the flow coming into the top of the can so that it stays full but doesn't overflow.

I've always coveted a Gravity Works washer because of the fill and dump process. Just seems like it's the best of all worlds, but we'll see. (assuming water temperature within limits ...)

 

[David Brown]

Ta Da!

http://www.rangeoflightphotography.com/Technical Manuals/Gravity Works AFW45 Film Washer.pdf

So help me, I searched for this before I started this thread, but didn't some up with it. Thanks to two folks over on the LF forum.

 

[Doremus Scudder]

David,

I responded to this same question over on the LF forum, but can't help chiming in on the "science vs belief" theme here.

It's insanely easy to test your film for residual hypo and see how your washing is doing (science). Fix a scrap sheet of film for your usual time, toss it in the washer and let it run at whatever rate you find most convenient and cost effective. Then pull the sheet out at five minutes, cut a strip off and test it with HT-2. Continue in 5 minute intervals until you find the time where you get no HT-2 stain at all, add a 10% buffer and, voilá, you can be assured of well-washed film every time if you just repeat that same process.

One test, one time. Then you can believe it too... And, if you ever need peace of mind, you can always test occasionally as a process control.

Best,

Doremus

 

[David Brown]

I responded to this same question over on the LF forum, but can't help chiming in on the "science vs belief" theme here.

It's insanely easy to test your film for residual hypo and see how your washing is doing (science)...

Thanks. I'm familiar with proper procedures. I hope you realize we were joking ...