Is there a chemist in the house?

[Calamity Jane]

Thanks David - good post!

My chemical supplier is the same one that supplies my company's Chem Lab (Manitoba Hydro) and the ether is reagent grade. I am sure it is sold in metal cans (since the suppliers don't like to blow themselves up either!) but I am checking with the supplier on that, whether or not is has been "stabalized", and about obtaining smaller quantities.

(Just got an e-mail from them - it IS available in smaller quantities, "anhydrous ACS reagent grade", stabalized with "BHT" - now I gotta find out whatinheck "BHT" is!)

As for working with the ether, I intend to do my initial mixing outside in the wide open spaces. Since the ether gets mixed with equal parts alcohol, I may do that mix right off the bat and store the ether/alcohol compond - I am checking with our senior chemical technician to see what effect that would have on the formation of peroxides.

I am building a "chamber" for the darkroom to contol vapours. It is actually a plywood box with a plexi windshield, holes to stick your arms in, with plexi windows on top so there is no need for electricals inside the box. (Looks like the chambers they use in the Level 4 Bio labs!)

I have installed a 4" exhaust duct from the darkroom directly to the outside and equipped it with an 80 CFM fan with a shaded pole motor (no brushes, no sparks, no source of ignition). This will connect directly to the chamber. With the lower explosive limit of ether being 1.9% I am going to make sure there's a steady wind blowing into the chamber and out the exhaust!

I am also going to add a BIG dry-chem fire extinguisher to the darkroom and a box of impervious disposable gloves! I even thought about a respirator (bottled air) but figured putting the exhaust fan on a UPS (in case of power failure) is probably more logical.

Paranoid? Who's paranoid? I didn't get to be 56 years old working in the sciences by being flippant about materials! If I do one day blow myself up, I want the explosion to be heard for 500 miles! ;-)

[Bob Phipps]

The answer about using a small refrigerator is out of the question. Small home frig. for keeping colas and the like has a major flaw - it is not spark proof. Laboratory refrigerators have special wiring, spark proof insulation, and ventilation for removal of accumulated evaporates before opening the door.

Working in genetic research in college, I used anethitizing either [ not ethyl, but similar properites] which we stored out of the building. We filled our fruit fly sleep jug in the safe building with .1 mL of either and then placed it on ice and came back to the lab. Thankfully by my junoir year a new product was developed that did not use either.

It is a wonder that early photography survived without the knowledge of the explosive dangers of the components of many of the solutions used. Worst of all was the flash powder made from "Lycopodium" spores. Hard to look at ground pine and think of it as explosive. Professor of Plant Physiology class took us to the AROTC rifle range to demonstrate its use.

[Kirk Keyes]

BHT - Butylated Hydroxytolulene, commonly used as a food preservative/antioxidant. See:

http://chemistry.about.com/library/weekly/aa082101a.htm

[Harold_4074]

From post above by Calamity:

"I am building a "chamber" for the darkroom to contol vapours. It is

actually a plywood box with a plexi windshield, holes to stick your arms

in, with plexi windows on top so there is no need for electricals inside

the box. (Looks like the chambers they use in the Level 4 Bio labs!)

I have installed a 4" exhaust duct from the darkroom directly to the

outside and equipped it with an 80 CFM fan with a shaded pole motor (no

brushes, no sparks, no source of ignition). This will connect directly to

the chamber. With the lower explosive limit of ether being 1.9% I am going

to make sure there's a steady wind blowing into the chamber and out the

exhaust!"

The idea is right, but there are a few things to keep in mind:

1) 80 CFM of air (if you actually have that much flow) will bring through your work area all of the dust, lint, etc. contained in 80 cubic feet of air, each minute. There is a class of aerosol collectors referred to as "plate impactors"; you may find that you have constructed one! Inlet filtering, of course, is the answer, but it will likely reduce the flow substantially.

2) Even a fairly small chamber can be hazardous if you are standing next to it and an explosion of any size occurs inside. (Say, some ether vapor ignited by static electricity). It takes only a few PSI of overpressure to accelerate a plastic window to a high enough velocity to cause some real unpleasantness. You might consider "blowout walls" of plastic film on three sides, supported by a light weight grid to resist the negative pressure developed by the fan.

3) A shaded pole motor is sparkless, but any fan can lead to static discharges caused by tribolelectricity (rubbing of dissimilar materials, such as dust and ductwork). If the flow is high enough that an ignitable concentration is never reached, then all is well. However, you should consider the worst case (a spilled bottle?) and plan accordingly. If the fan would take it, a water mist nozzle in the duct, right at the outlet of the work chamber, might be good insurance. In any case, resist the temptation to use PVC pipe or flexible plastic ducting, and electrically bond the pieces of the system.

[Calamity Jane]

Good points Harold! Thanks.

1) Dust. My new basement darkroom is remarkedly dust free (compared to any other room) but a nice intake filter on the chamber is a good idea.

2) Explosion. I had considered vapour barrier sheeting for the sides but didn't know how to stop it from sucking in. You, my friend, have hit on an elegant solution! Black builder's plastic for the sides.

3) Fan/duct. The duct work is all galvanized steel, electrically connected to ground and bonded together. The fan is all metal as well. As to static electricity, I will have to test that this winter when the humidity gets down near single digits. I suspect, with the amount of grounded metal (the ducting) and the low dust levels, there shoudn't be any static, but I will have to verify that.

I don't plan on handling raw ether in the chamber, only mixed collodion, but I will verify the air flow when it's done to know for sure how much ether evaporation is tollerable.

If it wasn't for these darned COLD Manitoba winters, I could work outside! Most chemicals though don't seem to like temperatures below -30 ;-)

[Donald Qualls]

Jane, I think the suggestion for an intake filter was for the entire darkroom -- to prevent the fan exhausting the chemical box from drawing in all sorts of crap that you'll then be constantly having to remove from conventional negatives, lenses, prints, etc. Better even than a simple filter would be a much larger-rated intake fan with filter, so the darkroom as a whole is very slightly pressurized -- then leaks will blow, rather than suck (and a leak that brings in dust really does suck!), and the fan exhausting the box won't be working against a pressure differential.

My experience suggests both ethanol and ethyl ether remain liquid and easily handled at -30 F, but that doesn't mean photographers work well at that temperature.

I wonder, occasionally, why collodion photographers haven't changed to working with nitrate lacquer, aka glider dope or nitrate dope -- it's almost identical to collodion, but the thinner contains neither ether nor acohol, isn't prone to peroxide formation, won't anesthetize the user (or at least not the way ether can), and is much less flammable than ether. There may be good reasons this close relative to collodion isn't used -- but I don't know what they are. Seems to me it might be worth looking into -- glider dope and its thinner are both a great deal cheaper than collodion and ether, too.

[Struan Gray]

Handling volatile solvents outdoors in extreme cold can give you frostbite. Loosely-fitting gloves you can shake off quickly are a standard precaution.

If you're really unlucky, you'll have cold burns to your hands, and flash burns to your face. :-)

[Harold_4074]

"My experience suggests both ethanol and ethyl ether remain liquid and easily handled at -30 F, but that doesn't mean photographers work well at that temperature."

Hmmm...ethanol is a pretty good antifreeze, but maybe handling ether while maintaining a high enough blood alcohol level to keep you from freezing at -30F wouldn't be such a great idea...

Regarding filtered positive-pressure air for the entire darkroom: this is actually a great idea if it can be pulled off, but I was actually referring to all of the lint, cat hair, etc. that would otherwise end up either as dust bunnies in the corners or in the lint trap of the clothes dryer. I would probably think in terms of a good, high-flow filter for the box, and some elastic-cuffed sleeves to seal between my wrists and the box wall (sort of like glovebox gloves, but without the loss of touch and dexterity). Collodion is a traditional wound dressing (liquid Band-Aid) so I wouldn't worry too much about working barehanded and the sleeves would keep all the crap on my clothes from winding up on the plates.

[Harold_4074]

Allow me to add: before someone becomes upset over the notion of working barehanded with wet-plate coating chemistry, I should point out that it may indeed contain unhealthy things not found in wound dressings (like cadmium bromide, perhaps).

On the other hand, anyone without the competence and/or sense to observe standard laboratory hygiene practices (washing hands, not tasting the chemistry, etc.) probably shouldn't be in a darkroom anyway.

(I have no reservations about Calamity Jane's ability to do these things safely---I checked out her website, and read about some of her other hobbies...)

[Mike Kovacs]

I didn't read the entire thread, so apologies if I'm repeating information. I am a chemist by training and run a research lab.

1. We are required to test our diethyl ether for peroxides yearly. The cans are dated when opened so we know when. Normally, we would use the entire volume up before the year elapsed. There is another flavour of ether that needs to be tested every 3 months that we do not stock.

2. Someone suggested to store diethyl ether in the refridgerator. There are explosion proofed refridgerators used in labs to do this. Not a good idea to do this at home folks, unless you physically modify it to locate the thermostat OUTSIDE the fridge. You could easily cause a nasty explosion.

My advice is to work in an extremely well ventilated area, think long and hard about any possible ignition sources (e.g. electric devices) and buy the ether in small bottles so you use them up well before peroxide formation becomes and issue.