Source of compressed air

[Ed Richards]

Any good alternatives to canned air for dusting off film before scanning and paper before printing? Anyone building a pump up air duster, like a small yard sprayer?

[Mike Chini]

You can build one with a simple compressor but it will make a heap of noise. I just go to Costco and get a three-pack of Dust-Off for $8 vs. 1 can for $8 at B&H.

[paulr]

A lot of labs use a compressor. Usually a big one that has a storage tank, so the motor isn't running all the time. You'd want one with a pretty good filter and moisure trap. A friend of mind did this for his darkroom.

For dusting off inkjet paper, I use a draftsman's brush. For dusting off film before darkroom printing, I like a small antistatic brush. I find i only need canned air for scanning wet-mounted film.

[John Cook]

I got a tank of CO2 for my darkroom from the local medical/industrial compressed gas dealer in the yellow pages.

Much less than a hundred dollars with all the hardware, nozzle, etc.

If it ever becomes exhausted (that was 15 years ago) my instructions are to simply exchange the empty tank for a full one. No need to purchase the tank and hardware but once.

Dramatically cheaper than those little spray cans. And no liquid mixed with the air.

Just a tad bulky for the gadget bag...

[Donald Qualls]

Very important concern with CO2, and less so with nitrogen: either one, in a closed darkroom, can kill you by simply developing a very slight leak. A leak can fill the darkroom with invisible, odorless gas, excluding oxygen, and cause suffocation in minutes after entering or over a longer time if you're in the room when the leak starts. I'd be concerned about using CO2 for dusting surfaces even in the absence of leaks -- the gas is toxic in concentrations as low as 4-5 percent by volume, causing rapid breathing, headache, fainting, convulsions, and death as concentration or exposure rises.

If the room is well ventilated, this is less of a concern, of course, but I'd prefer to use real compressed air, if there's a choice. Industrial compressed air can be obtained in pressure bottles at 2200 psi or higher, same pressure as nitrogen, is dried before bottling just as nitrogen and CO2 are dried in the separation process, and is much safer to use because it contains oxygen in the same proportion as ambient air.

On a side issue, rapid decompression and accompanying cooling can produce dry ice crystals in the exhaust flow of CO2 -- crystals which have the potential to damage a negative. Nitrogen is better, but air is best.

[Dave Schneider]

Ice crystals forming in the CO2 stream is not a problem if the compressed gas is dry to begin with. I have used CO2 for years in the darkroom, for air brushing and other applications where a noisy compressor would bother me. An air compressor musthave a suitable drying system that gets the dewpoint down to -40F or so and has good filters or you'll have a whole new set of problems. The time weighted average limit for CO2 is 5% by volume. Short term toxicity is about 25%. I wouldn't be too concerned about dusting off a lens or a negative with CO2. Just use some good common sense like shutting off the valve when you're done. Either nitrogen or CO2 will work fine. CO2 is sometimes easier and cheaper to obtain since it is used for the bars and such. A welding supply store can certainly set you up with a small cylinder, regulator, hoses and anything you need. A 15# cylinder usually lasts 1-2 years for me.

[Pat Kearns]

If the canned air doesn't blow the dust off then I use my SCUBA tank. I have to slowly turn on the valve otherwise blasting the negative with 3,250 psi will blow the negative out of the carrier. As all divers ask, "Gone down lately?" ;~)

[Alan Davenport]

I switched from Dust-Off type products to straight CO2 dusters when I realized how dead my lenses would be if I accidentally hit them with a liquid stream from one of those cans. I keep a cartridge-type CO2 duster in my camera bag.

[Michael_5731]

Try a bicycle pump, or a balloon pump with a short hose. It makes for a two handed operation but then it never runs out of air at the wrong time.

[Jim McD]

I have to second the recommendation for a SCUBA tank. It's clean and dry and cheap. A diver friend lets me use his "almost expired" tanks with an old regulator and a "blower" nozzle avail;able at a dive shop, it lasts me 2 years of regular use and he gets his tank back to be recertified.

I have used CO2, compressed air, and the canned stuff-I am happiest with a SCUBA tank. Buy your friendly local diver a case of beer with every tank switch and you may never run out.

[Richard Ide]

You can also buy a small air tank which you can fill at a service station with the air hose for inflating tires. The amount of air needed for cleaning film etc. is minimal so one filling would last a long time. I don't know the equivalent of "Canadian Tire" in the USA but an auto parts shop should be able to help.

Richard

[John Kasaian]

...or just keep a politician close by----they never seem to run out of air!

[Steve Clark]

Good idea John, except that it is HOT AIR !!!

[Alec Jones]

First I use an electronic antistatic brush for this purpose. If a spot of dust remains, I then use a rubber ear syringe to blow it off. They produce a powerful "puff". I have nitrogen available, but don't use it for that purpose, since if the first two procedures don't get it off, chances are nothing else will either.

[Mike Gudzinowicz]

I would like to reiterate Donald's warning concerning the storage and use of
large tanks of CO2 in the darkroom.

At the medical school where I was doing my graduate work, a medical student
attempted to walk through a small courtyard that contained a large CO2 storage
tank. The tank's valve had been been damaged by a supplier and developed
a small leak filling the ground level area with CO2. The medical student died
in the courtyard due to short term exposure to high concentrations of CO2.

There are safer alternatives.

I don't have a dust problem since filtered air is forced into the room by
an enclosed fan. The positive pressure of the filtered air keeps dust out
of the room. Once a year, I wipe down all of the surfaces in the darkroom.

Also, do not use CO2 to displace air from a developer bottle. The CO2 is
absorbed by the solution and converted to carbonic acid, which decreases
the pH killing the developer.

Mike

[Dan Jolicoeur]

"I keep a cartridge-type CO2 duster in my camera bag."

Alan, Do you have a source for this CO2 duster? I have been looking for one for a while. I will not use Dust-Off on my camera equipment.
Thanks,

[Ed Richards]

I had not thought about an anti-static brush, but that might be a better alternative. How do you clean them and what luck have folks had with them? I must admit that brushing makes more sense than rearranging the dust.

[Conrad Hoffman]

I've never had need for more than a large rubber ear syringe. I think I bought my last can of Dust-off back around 1974- gave it up due to the cost. If I really wanted compressed air, I'd use one of the $20 tire filling tanks, or buy medium sized cylinders of dry nitrogen at the welding supply store. As said above, the regulator and tank will be a one time expense, then you just exchange it. Close the tank valve when not in use- the welding store should have some kind of safety rule sheet they can give you.

[Donald Qualls]

If you want to avoid just rearranging the dust, don't blow, and don't brush. Suck instead.

Use a tiny vacuum (like the ones sold for cleaning computer keyboards; they can be had for as little as $20), and the dust is sucked into a filter bag and trapped instead of being kicked into the air to settle somewhere else (enlarger lens, condenser glass, another negative, or worst of all, unexposed film during loading holders). And there's no chance of a vacuum cleaning suffocating you; if your darkroom is equipped with GFCIs as it should be on all outlets, there's no more electrical hazard than in operating the enlarger itself. The same vacuum can, of course, be used to clean inside bellows, film holders, etc.