fighting dust

swchris · Sep 5, 2014

Up until now I more or less only enlarged 35mm negatives, in a glassless carrier. I got some dust spots once in a while, but just took out the negative from the carrier, wiped it clean with an antistatic cloth and put it back in.

Now I've started to enlarge 6x9 negatives in a glass carrier. And I just cannot achieve a spotless print. With the glass at the top and the bottom there are now six surfaces to make dust free instead of two. And the surfaces are much larger.

What do you people do to avoid dust? Any hints are very much appreciated!

Bob Carnie · Sep 5, 2014

Raise the humidity, use scanner glass cleaner, I use a high power loupe to look at the sandwich, I also have qtips and cleaner availble, gunk off, and a handy can of compressed air with the nossel removed..I also make sure my negs are stored in perfect conditions, and use an antistatic cloth supplied by Ilford.
If the negative is old I will clean it with warm water, photoflow and redry before attempting to put in enlarger.

I tape the negative with scotch tape to the glass and work on the inside sandwich first, once happy with that , then I close the sandwich and clean the two outside surfaces. Humidity is probably the number one tool on the list.

DannL. · Sep 5, 2014

Carpet on the floor is an excellent source for airborne dust. Just walk across a carpeted floor to create a mini dust storm. If you have carpet in the darkroom, you might consider a plastic or wood floor covering. Even on a temporary basis. Chairs with cloth seat covers . . . another excellent source. Just some ideas.

swchris · Sep 5, 2014

Bob Carnie said:
Raise the humidity

Bob Carnie said:
Humidity is probably the number one tool on the list.

What is a good method to raise humidity?
And won't I get a problem that the enlarging lenses breed fungus?

Bob Carnie said:
I tape the negative with scotch tape to the glass and work on the inside sandwich first, once happy with that , then I close the sandwich and clean the two outside surfaces.

I'm from Germany so I don't know what exactly you mean with "scotch tape". And I don't get the flow of operation. After you have taped the negative to the glass how do you "work on the inside"?

swchris · Sep 5, 2014

DannL. said:
Carpet on the floor is an excellent source for airborne dust. Just walk across a carpeted floor to create a mini dust storm.

I don't have a carpet on the floor.

DannL. said:
If you have carpet in the darkroom, you might consider a plastic or wood floor covering. Even on a temporary basis.

I've got a plastic floor covering. And I think it might introduce static electricity which could attract dust?

Truzi · Sep 5, 2014

swchris said:
I'm from Germany so I don't know what exactly you mean with "scotch tape"

Scotch is a brand name. It's cellophane tape (if that helps) - the clear tape you might use when wrapping gifts.

Bill Burk · Sep 6, 2014

Just take comfort in the knowledge that the worst dust spots are the ones that fall on the film before the photo is taken... Or scratches while processing.

After that, anything else is easy to spot (because white spots respond very well to brush spotting)...

Are you using a condenser or diffusion enlarger? I find dust spots disappear on my diffusion setup.

Mick Fagan · Sep 6, 2014

I would suggest you consider Scotch Magic tape.

http://multimedia.3m.com/mws/mediawebserver?jjjjjjTRbvyjDNkjxNkjjKt_wV2JJJJI-

This is available in sizes from 12.7mm wide or wider widths up to about 25mm, it comes in 33m or 66m lengths.

I know it's available from an office supply shop in Germering (Munich) as I bought some there this June.

The removability of this tape on negatives is very good. Basically this is the same adhesive and removability, as those yellow "Post it Notes" one sees in many offices.

I use this to hinge the negative to the glass or metal part of the carrier, to enable pretty good cleaning action to be taken. Then, to let the negative drop back to the correct position.

I also use it with minor dust particles on the negative, both the emulsion side and the non emulsion side. The technique is simple, grab a bit of the tape between thumb and finger, pull out about 40mm to 50mm of tape, then let the slack tape fall onto the part of the negative with dust particles, then lift off. Sometimes I press the tape gently onto the negative to get more stubborn particles, leave it for a few seconds, then lift off. Do not lift off in a hurry, just normally.

The adhesive qualities of this tape are not that strong, but usually strong enough to remove particles, hold the negative firmly, and when finally removed, leave no adhesive on the negative.

I've been using this on negatives for around 35 years.

Bob Carnie's hint about humidity is spot on, it is a factor as to whether or not you get a lot or little dust and dirt particles. You can raise humidity by placing a boiling electric kettle and let it steam a bit, alternatively, place an iron (Bügeleisen) with a shot of steam button and press the button every now and then to get some steam.

Mick.

Mr Bill · Sep 6, 2014

swchris said:
What is a good method to raise humidity?
And won't I get a problem that the enlarging lenses breed fungus?

You ideally want your relative humidity to be about 50%; lower than about 40% can be a problem with static, higher than about 60% can lead to rusty equipment (long before lens fungus is a problem).

You can probably buy small humidifiers in your local discount store or hardware store. Don't let them get close to your film, as they typically put tiny droplets of water into the air; these will make marks on your film.

By the way, you don't need to worry about the plastic cover on your floor. You'll probably generate a charge on yourself, same as you would shuffling your feet on carpet, but this will drain off as soon as you touch any grounded metal. At any rate, it won't transfer to the film. (If you could put your own static charge on film by touching it, you'd also be able to bleed the charge off by touching the film while grounded, and we know that doesn't happen.)

The way static charges are generated on film are by unwinding it from a roll, or sliding it out of a plastic sleeve, or rubbing it with something. If you have somewhere near 50% RH, the charge will bleed off by itself in probably a half minute or so. (Air ionizer units can bleed off the charge within a second or two.)

Bob Carnie · Sep 6, 2014

humidifier

swchris said:
What is a good method to raise humidity?
And won't I get a problem that the enlarging lenses breed fungus?

thin tape

between the two glass

I'm from Germany so I don't know what exactly you mean with "scotch tape". And I don't get the flow of operation. After you have taped the negative to the glass how do you "work on the inside"?

swchris · Sep 7, 2014

Thanks for the hints!

The enlarger used for 6x9 is a condenser enlarger, the 35mm is a diffusion enlarger.

I'll try this week if I can get to a spot free print.

Arklatexian · Sep 7, 2014

My darkroom is "freestanding" and when I built it we drove a long "grounding" rod deep into the earth as a ground for everything in the darkroom i.e. all wall plugs are well grounded. I have made sure all of my enlargers have grounding plugs and this seems to have really helped reduce dust caused by static electricity. Try it, you'll like it.....Regards.

Mainecoonmaniac · Sep 8, 2014

What I would do is vacuum your enlarger. Especially the lamp housing above your neg carrier. I've used glass carriers, but they're too dusty for me. There are 6 surfaces to clean vs 2 for glassless carriers. Humidity will help with static so dust cling to your negs. Wipe your baseboard with a damp cloth once in a while. Carpet in a darkroom is a bad thing. I rarely have dust on my prints. I also use a air bulb to blow my negs off.

David Allen · Sep 8, 2014

You are having to contend with several related problems:

In comparison to diffuser enlargers condenser enlargers show more dust (one solution is to introduce an opaque piece of perspex above the negative stage)
As you rightly say, you are having to contend with a number of surfaces where dust can gather: negative and glasses. I have always worked with glassless carriers and rarely have any big issues with dust. Perhaps you can find or make a glassless carrier?

Other things that can help a lot are:

to thoroughly clean the whole enlarger using anti-static wipes
make sure your enlarger is earthed well - not just the power supply but also the metal housing
get an empty washing-up liquid bottle (spülmittel) and thoroughly clean and dry it. This can then be used to blow both sides of the negative to dislodge dust. It is much better than the little dust off devices with a brush that are sold because (a) the washing-up bottle has a much larger capacity of air to direct towards the negative and (b) the brushes on the little devices sold by so many photographic suppliers retain dust on the hairs of the brush that you then 'shoot' onto your negatives.

Best of luck solving your problems.

David.
www.dsallen.de

chrisaisenbrey · Sep 8, 2014

Truzi said:
Scotch is a brand name. It's cellophane tape (if that helps) - the clear tape you might use when wrapping gifts.

Tesa (Germany) <=> Scotch (rest of the world) ;-)

Old_Dick · Sep 8, 2014

While it has been years since I've been in the darkroom (slowly trying to get back) I use to use an antistatic spray on the negatives. It actually solved two problems, dust and scratches. Spray it on and wipe with a lint free cloth. Forty years later, the negatives still look great. I don't remember the brand of spray. At the time I worked in a printing factory and static was a problem. We would spray the presses, boots and places we would stand. Think small building size high speed presses.

HTTY
Dick

Principal Unix System Engineer Yoyodyne Propulsion Systems

jp80874 · Sep 8, 2014

How do you prevent dust in your dark room? I vacuum the floor and wipe down the walls and other surfaces with a damp rag. If your darkroom is in the basement, are the concrete walls sealed? Is the ceiling sealed and air tight? Do you filter the air coming into the darkroom? I use a furnace filter with an intake fan. After you develop the negatives and rinse them how do you protect the drying negatives from dust? I use a cotton/canvas rolling closet meant for storing clothes. The canvas lets the moisture out and keeps the dust from coming in. I clean all on my enlarger glass just as I clean the glasses I wear on my eyes. I do this before I start enlarging and check for dust periodically through the darkroom session. Some dust still gets through, but it is a whole lot less that if I didn't do these things.

John Powers

David Allen · Sep 8, 2014

jp80874 said:
How do you prevent dust in your dark room? I vacuum the floor and wipe down the walls and other surfaces with a damp rag. If your darkroom is in the basement, are the concrete walls sealed? Is the ceiling sealed and air tight? Do you filter the air coming into the darkroom? I use a furnace filter with an intake fan. After you develop the negatives and rinse them how do you protect the drying negatives from dust? I use a cotton/canvas rolling closet meant for storing clothes. The canvas lets the moisture out and keeps the dust from coming in. I clean all on my enlarger glass just as I clean the glasses I wear on my eyes. I do this before I start enlarging and check for dust periodically through the darkroom session. Some dust still gets through, but it is a whole lot less that if I didn't do these things.

John Powers

As I mentioned in another thread, Never ever vacuum in a darkroom. You have to understand that the hoover sucks in larger particles that are trapped in the bag/cylinder (depending upon design of the hoover) but the exhaust pumps out tons of micro-dust that you can't see until they get stuck (with a massive magnetic charge due to passage through the hoover mechanism) on to your negatives.

If you must hoover then you need to double earth your hoover but you are still courting untold problems.

Semi-damp wiping of all surfaces including equipment is the most effective.

If you have carpet/rugs in the darkroom get rid of them as soon as possible.

likewise if you have vinyl, lino or concrete on the floor never sweep or hoover it but use a slightly damp mop and clean the mop after every few square metres.

Bests,

David.
www.dsallen.de

Old_Dick · Sep 8, 2014

One more thing to think about, the source. Having worked in a cleanroom you begin to realize how dirty you and your clothes are. Clean hair and clean clothes, using the Hoover on yourself will help with keeping your darkroom dust free.

Fall Regards
Dick

Principal Unix System Engineer, Yoyodyne Propulsion Systems

fighting dust

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