Why canned air?

[wontonny]

It's common for people to use those canned air things to get dust off of their negatives...but why? I'm guessing just pure convenience. What I'm trying to get at is can I use plain old compressed air from a shop air compressor to dust my negs? Is the canned air 'safer' some how for my negatives?

Also, do those negative brushes work? Would those be a better alternative to the canned air?

 

[Chris101]

Make sure your compressed air is well filtered. The last thing you want is for a drop of some unidentified glop to land on your negative!

 

[Chriscrawfordphoto]

air compressors can sometimes have oils from the compressor machineary and other gunk in the air. Canned air is clean.

 

[dmr]

I know that canned "air" is not really air, but some of us don't have an air compressor and I'm sure that the canned whatever-it-is has fewer contaminants than human breath does. 🙂

 

[kully]

The canned 'air' I get from Costco here in the UK (made in US) has a habit of occasionally spewing forth bits of liquid propellant.

 

[photophorous]

Yeah, regular old garage air compressors can cover your negs in tiny oil spots. They are not as clean as canned air.

I'm curious to know if there is a better method too, because the amount of dust on my negs seems to vary a lot and I can't seem to figure out why.

Paul

 

[rich815]

The canned 'air' I get from Costco here in the UK (made in US) has a habit of occasionally spewing forth bits of liquid propellant.

They all do if you tilt the can. Don't.

 

[Keith]

The canned 'air' I get from Costco here in the UK (made in US) has a habit of occasionally spewing forth bits of liquid propellant.

I had that problem too ... it's not a pretty sight to see a negative splattered with liquid propellant. I now use a cheap set of bellows made of plastic ... the sort you use to pump up air beds etc.

 

[Sparrow]

Yeah, regular old garage air compressors can cover your negs in tiny oil spots. They are not as clean as canned air.

I'm curious to know if there is a better method too, because the amount of dust on my negs seems to vary a lot and I can't seem to figure out why.

Paul

All else being equal humidity is the biggest factor, low humidity and the film gets a bigger static charge.

An air line feed from a compressor reservoir needs a Regulator, Gauge, and Moisture Trap/Aggregator, 60psi from a blast gun will begin to remove the emulsion from a colour print neg

 

[kully]

Thanks for the hints on the Dust Off cans.

For the past few days I've been using my breath, seems to be working fine. Perhaps not for when I've got a cold though.

 

[oftheherd]

Thanks for the hints on the Dust Off cans.

For the past few days I've been using my breath, seems to be working fine. Perhaps not for when I've got a cold though.

I used my breath in emergencies for lenses more than film. Some say no matter how careful, some liquid droplets will come from your mouth or lungs when you do that. With lenses, I usually try to hold the lens horizontally and blow across it. Not an option with film. I sometimes use a blower from a blower-brush.

Does anybody know if they still make the brushes with the radioactive inserts to change the polarity of the electricity? Or the anti-static squeeze mechanisms for both film and records?

 

[newsgrunt]

If you use a filter between the compressor and line, you shouldn't have issues with oils.

I use an oil-less compressor which is very quiet and have a second pressure regulator near the enlarger bench to drop the pressure down so I don't blow the neg out the carrier. Cheaper and less wasteful than the canned air in the long run. All the darkrooms I've worked in had lines at every enlarger so I guess I was spoiled.

 

[Sparrow]

A dual action airbrush makes a good blast gun as you stay in control of the air volume, you can also fill it with distilled water if you need to get really serious. I have an old worn out Super 63 that I use

 

[photophorous]

All else being equal humidity is the biggest factor, low humidity and the film gets a bigger static charge.

An air line feed from a compressor reservoir needs a Regulator, Gauge, and Moisture Trap/Aggregator, 60psi from a blast gun will begin to remove the emulsion from a colour print neg

Thanks for the tip, Sparrow. I do try to run the hot water in the bathroom for a few minutes before I hang my negs to dry.

Has anyone been crazy enough to try using a humidifier in the room where they scan negatives? I guess if it's not too humid, it wouldn't cause any problems, but the idea makes me a little nervous.

Paul

 

[Tuolumne]

I Used to use a Zerostat ionic anti-static gun on my vinyl records to clear them of dust many years ago. It actually worked quite well. I just did a search for Zerostat on Google, and what do you know, they are still available. Try here: http://www.elusivedisc.com/prodinfo.asp?number=ZEROSTATB
Of course they cost about 9 times what I paid for them back in the '60s, but I guess that's inflation for you!

/T

 

[Tuolumne]

One other point about canned air: You should never shake before using. That just mixes propellant into the compressed air.

/T

 

[MartinP]

While working in a darkroom we used to use Kenco compressed gas to blow dust off the 5x4 and 10x8 negs. Those were the big cans with a re-usable filter/trigger assembly on top and i don't recall a liquid-propellant problem. Since then I have used air from various squeezy bottles to remove dust. Currently I use one of those Giotto squeezy rocket things and it works fine.

I second the hint to avoid keeping the work area as a bone dry atmosphere, to reduce static problems. Indeed, I once had an I.T. contract in a factory using plastic cups and they reduced the static by spraying the outside with a magic "something". When I asked about it, it turned out to be something which increased the surface moisture on the outside of the cup, thereby leaking away any static charge, so a tiny amount of humidity may help a lot.

 

[payasam]

I use a rubber bulb with a nozzle. Get it from a shop that caters to people who repair mechanical clocks.

 

[Tuolumne]

While working in a darkroom we used to use Kenco compressed gas to blow dust off the 5x4 and 10x8 negs. Those were the big cans with a re-usable filter/trigger assembly on top and i don't recall a liquid-propellant problem. Since then I have used air from various squeezy bottles to remove dust. Currently I use one of those Giotto squeezy rocket things and it works fine.

I second the hint to avoid keeping the work area as a bone dry atmosphere, to reduce static problems. Indeed, I once had an I.T. contract in a factory using plastic cups and they reduced the static by spraying the outside with a magic "something". When I asked about it, it turned out to be something which increased the surface moisture on the outside of the cup, thereby leaking away any static charge, so a tiny amount of humidity may help a lot.

In my early days as a computer operator we used to run a water humidifier to help reduce static charge. One of my jobs was to fill the humidifier with water from a hose every morning. It took a while and was boring so I would usually just start the hose and then go on about my business, trying to remember to return to shut it off before the humidifier was full. Many was the morning that someone from the lab below ours would run up screaming that there was water dripping from the ceiling into their lab. Don't let this happen to you! :bang:

/T

 

[kuzano]

A hobby compressor as used for Air Brush

A hobby compressor as used for Air Brush

Using a dual action air brush was mentioned. It might be better to use one of the small compressors that are used with air brushes, and a line with a small air gun rather than the airbrush.

Many shop air compressors are oil lubricated and use a piston to displace air. Moisture is drawn in with the air and unless filtered goes out the nozzle. Oil in the compressor leaks past the piston and goes out with the air which may already also have moisture in it. It takes about 200 dollars worth of traps and filters to clean the air, and then there is always some contaminant getting through as the traps and filters need constant cleaning and eventually wear out. I used to paint my own cars with a fully equipped hobby shop.

The little hobby compressors use a diaphragm to displace air, which precludes oil in the air, but you still have to filter for moisture, since that is drawn in through the air supply at the front end. Also, the hobby compressors don't often reach the very high pressures of a shop compressor. Pressure should be controlled by a gauge and control valve coming out the output side before the line.

The canned air is filled with filtered air (presumably, just like bottled water comes from artesian springs high in the mountains, right?). Holding them upright reduces the propellant from getting in the output nozzle, as has been pointed out.

The real issue is the price of single cans of air, often reaching $6 to $10. Stores like Costco (Big box store), often sell the air shrinkwrapped 4 to a pack for $11.99. And the cans are often larger than sold in art and photo supply houses.