Magical Substitutions for Darkroom Work

VINEGAR STOP BATH

You do not need to use manufactured stop bath to halt development when processing film or prints.  Stop bath is a solution of 2% glacial acetic acid.  If you purchase white vinegar you can mix it with distilled water to make your own stop bath.  Do not purchase colored or odor free or basalmic vinegar, just Plain Jane white vinegar.  The vinegar will state it is so many grains.  10 grains = 1% acid.  50 grains = 5% acid.  You want to mix your vinegar with the water to arrive at a 2% acid solution.  Mix to the following ratios depending on the concentration of the vinegar you have.

3% = 2:1 for film. 3:1 for paper.
5% = 1:3 for film.  2:3 for paper.
10% = 1:5 for film. 1:10 for paper.
15% = 1:8 for film. 1:16 for paper.

Stop bath for paper is general twice as diluted as that mixed for use in processing film.

Use this as you would normally use your stop bath.  For processing film, a vinegar stop should be used as a one-shot stop.  This means that once you use it, dump it.  It will be close to exhaustion if not completely exhausted.

If you are using it for prints, it is best to test its duration of strength.  Take an unexposed sheet of paper and process it normally.  Continue this a sheet at a time until you notice paper that is shading due to unrinsed silver halides becoming exposed by light.  You will know that your stop will be good for as many sheets of paper as have processed properly.


WINDOW-SIZED DAYTIME SAFELIGHT

Have a window you need to black out?  You do not need to use black material.  I have a large window in my walk-in closet that is now my dry side portion of the darkroom.  I covered this large window (48"x30") with an old dark red bed sheet.  I folded it over three times and stapled it around the sill.  The next afternoon I wanted to see just how little light was coming in as the window faces west and catches a lot of brilliant direct afternoon sunlight.  Well, imagine my immense pleasure when I realized I had created a window-sized daytime safelight.  I checked for paper fogging and it is safe out to ten minutes.

Happy accidental discovery but if you have a window that can be put to this use, do not hesitate to give it a try.


LARGE FORMAT FOCUSING CLOTHS NOW AVAILABLE ... AT WALMART

Though not necessarily related directly to the darkroom, I thought I would pass this along here.  Walmart sells blackout cloth.  This is intended for blacking out normal sized windows.  The fabric is heavy, thick fabric that claims to block 99% of all light.  It measures 42"x54".  The bonus, the reverse side is white.  This is perfect for a large format camera focusing cloth.  And for only about $9.00 USD.

Oh, and I suppose you could purchase it to black out your windows in the darkroom.  But that would negate any opportunity for the aforementioned window-sized safelight.

More to follow...