Nitrogen System for Dust Removal and Chemical Preservation

[Rafal Lukawiecki]

There are several references in various APUG threads on how some people (notably PE) have replaced a need for troublesome (oil + moisture) air compressors, expensive and fluid-ejaculating cans of compressed "air", etc, with just a cylinder of compressed nitrogen. I wanted to ask what bits I would need to assemble to do it comfortably and safely. I understand I need a regulator (what pressure?), some kind of a hose (what type?) and a nozzle/trigger valve (which one did you find to be the most convenient in use?)

I am curious if you store the cylinder outdoors with a pipeline going through the wall (my intention), or do you keep it in the darkroom.

I plan to use it mainly for blowing dust off negatives before placing them in the carrier, for displacing air from some part-empty chemical bottles, and for dusting prints before dry-mounting. If you use such a system—many thanks for your guidance.

 

[Sirius Glass]

I use DustOff! spray.

 

[Photo Engineer]

Any type of plastic tubing that fits your connectors will work. You will need a valve at the end to control and direct the Nitrogen. I just set the pressure to a value that gives me a good, gentle flow and there is no problem. You don't want to splash the solutions around, nor do you want to take forever using the Nitrogen to replace the air.

PE

 

[Nodda Duma]

If you go this route, make sure you use adequate safety procedures in securing the cylinder in an upright position. You do NOT want a full cylinder falling over and busting the valve off.

 

[winterclock]

A trip to a local welding supplier will get you all that you need.

 

[AgX]

You need the cylinder with valve, a pressure regulator, and an outlet valve. And as indicated a tank holder.
If you buy these things apart watch out for fitting threads. Best contact a major industrial supplier who also services the tanks in advance. Sooner or later you have to visit him anyway.
Be aware that all that is likely to become expensive.

 

[wildbill]

I use DustOff! spray.

so helpful.

 

[AgX]

If you go this route, make sure you use adequate safety procedures in securing the cylinder in an upright position. You do NOT want a full cylinder falling over and busting the valve off.

Valves ripped off:

https://www.youtube.com/watch?v=3cLrb7M7Mtw

 

[Ken Nadvornick]

If you go this route, make sure you use adequate safety procedures in securing the cylinder in an upright position. You do NOT want a full cylinder falling over and busting the valve off.

Or more subtly, having a regulator/valve/hose assembly that has a slow leak, if the cylinder is kept inside a closed darkroom. Nitrogen is not poisonous, but if you fill up the room with it you may end up becoming just like the purged bottle of D-76 that now can't oxidize...



Ken

 

[Photo Engineer]

The tanks shown in the youtube presentation are quite small and low pressure compared to most welding tank size vessels of Nitrogen. Make sure that the tank is clamped upright in a safe position. Then if anything goes wrong, the force is downwards to the floor. I have mine on a concrete floor attached to the metal pipe that hold up the I beam for the entire building. I used bungee cords to hold it to the metal pipe.

My father told me of a welding tank that fell off a loading dock onto railroad tracks and the track itself broke off the valve. At that point, the tank was at a 45 deg angle pointed at the ceiling of the warehouse. It took off and went through the ceiling, and they had to send out a group of workers to find the empty tank. These are dangerous. But, I grew up with a family of welders and metalworkers and knew this since I was a small child.

PS: My Nitrogen is only turned on for the short time I use it to fill solution tanks. I use antistat brushes for the dust removal. My line does have a small leak which I cannot find and these are really hard to find.

PE

 

[Gerald C Koch]

The choice of bottle type, either glass or PET plastic, is probably more important than trying to replace the air in bottles. Nitrogen is slightly lighter than air. Gases used to replace the air in bottles are usually heavier than air.

 

[Sirius Glass]

Metal straps are better for holding down tanks than bungee cords.

 

[Photo Engineer]

Metal straps are better for holding down tanks than bungee cords.

Yes, but on a concrete floor, the force is downward to the floor, then gravel, then mud! It ain't goin' far - no how, no way.

PE

 

[Nodda Duma]

There was a story from when I worked for the Navy about a full-sized tank tipping over in a lab and the valve breaking in an off-set manner. So the tank went crazy like a 100 lb bottle rocket without the stick. Destroyed everything in the lab. Luckily no one was inside at the time.

 

[gone]

Highly pressurized metal containers are not something I want in my place. Once, while recharging an A/C system on a Toyota, I inadvertently placed the intake side of my gauges on the high side of the car's compressor. I immediately felt the freon can vibrating in my hand when I opened the gauge to deliver the freon, and gave the gauges a quick look. The low side needle had spiked. I dropped the can, ran, and about one second later the can exploded, blowing a hole right through the cinder block side of the shop building. This is why we had signs warning customers to stay out of the shop. If I had been a tiny bit slower, and that can had been pointed at me like it usually was when I recharged a system, I'd be dead now.

Another time I was out sand blasting at a steel fabrication shop when the line that fed the sand blaster apparently got clogged w/ wet sand and exploded like a small bomb about 6' from my hands. That probably took a few years off my life for sure. My boss said to just replace the line and get back to work! I told him to take that job and shove it (the Southern way of giving your employer notice) and never came back. A welder I knew was killed when a small bit of smoking hot metal hit his shirt pocket right where his pressurized cigarette lighter resided (right by his heart). Myth busters said it can't happen. Yeah, right.

https://www.youtube.com/watch?v=upJKCcoMcFk

If anything can go wrong, it will. Get yourself a bottle of Canned Air and a Kinetronics dust brush. Me, I just use one of those squeeze gizmos for air and the aforementioned brush. The other brush that I had before this one was radioactive w/ the same element that killed that Russian spy a while back. It only takes a teeny, tiny amount to do the deed too.

 

[Sirius Glass]

To really destroy a laboratory there is nothing like a full blown old fashion alkali [lithium, sodium, potassium, ...] fire. Even solid steel tables vaporize.

 

[cliveh]

I plan to use it mainly for blowing dust off negatives before placing them in the carrier, for displacing air from some part-empty chemical bottles, and for dusting prints before dry-mounting. If you use such a system—many thanks for your guidance.

I think you are wasting your time with this, for as you blow off dust, the resulting airspace is replaced with other air containing dust.

 

[Mainecoonmaniac]

I like my air bulb. Simple and gives me a good firm hand shake after using it for years.

http://www.bhphotovideo.com/bnh/controller/home?O=&sku=259157&is=REG&Q=&A=details

 

[Bob Carnie]

Me too.. I take off the little red hose( don't ask why ) painful lesson. I find this is all I need and I do a lot of printing with glass carriers.

humidity in the room will solve a lot of issus.

I use DustOff! spray.

 

[Bob Carnie]

Every major lab I worked at used air hoses under pressure.. Every major lab I worked at had pitted and oil on their lenses..

Dust Off and humidity.

 

[Ken Nadvornick]

I believe I read somewhere that there is a difference in available grades of nitrogen, the desirable one supposedly being "dry" nitrogen? Not sure what that implies the alternative is...

But I also don't know that isn't just a photo darkroom urban legend...

Ken

 

[Nodda Duma]

Dry nitrogen means all water has been removed from the nitrogen...usually accomplished by distillation or by supplying from on-site liquid nitrogen. Hermetically-sealed optical assemblies are usually assembled under dry-nitrogen flow. A common example would be a quality riflescope to avoid internal condensation.

 

[wiltw]

My Nitrogen is only turned on for the short time I use it to fill solution tanks. I use antistat brushes for the dust removal. My line does have a small leak which I cannot find and these are really hard to find.

PE

A little dishwashing detergent added to water, sprayed from a spray bottle onto the pressurized line...watch for bubbles forming, indicates where the leak(s) is.

 

[ChuckP]

You might also want to check with your insurance company. Your home policy may not cover any damages or injuries caused by a pressure tank in the house.

 

[Photo Engineer]

Wilt, Chuck, to answer your comments, first - some of the line runs through walls and cannot be checked. I have joints in the lines which are hard to seal and etc.... But, one tank - with leak - has lasted about 10 years. And, I am insured up to a point which is sufficient.

Thanks.

PE