Shooing dust- compressor for the new darkroom?

[Steven Ruttenberg]

You can either waste hundreds of dollars on canned air over the years, potentially with nasty propellants in them too, or buy a good compressor. I have not only sold thousands of compressors prior to retirement, but designed them. Today you can get some very quiet ones that run cool (the opposite - running hot, leads to condensation in the tank, and then water in the air line), that are fairly affordable, are compact, and use relatively little electricity. But don't be fooled by all the too good to be true false labeling, ridiculously low prices, and toy construction of typical home center compressors. I recommend LOW RPM units which produce volume not by revving up some tiny piston to the noise level of a chainsaw, but that potentially use two small tandem pistons at lower RPM. Really good US made small portable compressors are now out of production. But some relatively decent imports like the Rol Air JC10 are readily available and almost as quiet as a refrigerator. Then you want to add a micro-filtration system to your air lines, which should be of a hose material that doesn't break down and shed grease or particulates itself. If you pay ten bucks for a hose, you are a fool. Degrease all fittings and airguns with alcohol or similar solvent before darkroom use. You don't need high pressure in a darkroom; set the regulator around 30 to 40 PSI. And never ever ever believe the horsepower and CFM ratings on consumer grade compressors; it's all BS. The compressor should be in an adjacent room, with the air line going through the wall. It's not the air coming out of the hose you need to worry about
stirring up dust, but the rotating fan cooling the compressor motor itself. But if your darkroom is just too damn dusty to begin with, don't ask for my sympathy. I've spoken previously about the correct kinds of vacuums for darkrooms, which you're not going to find at Cheapo Depot either.

I have been looking for a new compressor, so what would be a good compressor? I know you mentioned one above, but are there any others? Also, what would be a good micro filtration system to put in line with the hose? What kind of hose too? And lastly, what type of vacuum cleaner would be best to get?

[Fred L]

If you're going to get a compressor, I strongly suggest finding the quietest one you can afford. I have a Campbell Hausfeld and while great for shop work, it was way too loud. Found a used Gast and it's so much quieter. Make sure you drain the tank every now and then other wise the compressor may shut down (safety feature ?).

I have a pressure gauge before the line leading to the pistol trigger blower. Lower pressure is necessary if you're using glassless carriers.

[Drew Wiley]

There are several private labels of that particular compressor, but I mentioned just one because it is specifically identifiable. There are more junk toy compressors out there than a puppy farm has fleas. I personally use Thomas compressors, but they're no longer made. I don't know if the imports will last anywhere as long, but home darkroom use isn't anywhere near as demanding as construction or cabinet shop applications. True HEPA vacs imply far more than just a HEPA filter, but a totally sealed system with no back-door routes for dust to get past. I strongly recommend the smaller Festool units, but they aren't cheap; allow several hundred dollars, and then pray your wife won't like it so much that you never get it back! (They're quiet and pick up everything an ordinary vac merely scatters; antistatic too.) Micro in-line filters aren't cheap either, but you don't need anything big, so fifty bucks or so would be an ample budget apiece for those. Again, my own are more industrial duty and not routinely available; but places like Grainger offer a selection. They're rated in microns. You need 1/4 pipe-thread ports (nothing big). If you have a quiet cool-running compressor it won't collect too much water, but you need to routinely drain your compressor tank using the valve at the bottom. Hoses easy to keep clean are made from nylon or polyester. These don't take the kind of abuse typical on construction project; but hopefully, a darkroom will be past that phase when you get to using it. Avoid cheap rubber hoses from auto parts stores, home centers etc, also vinyl hoses - which might resemble polyester hoses, but are far more fragile.

[Peter De Smidt]

I used to drive by the Thomas factory regularly. It's too bad they no longer make compressors. My neighbor has one.

[Drew Wiley]

Thomas made a good portable compressor but wasn't very smart about marketing them. They were bought out by Gardner-Denver, who moved mfg to Louisiana. The small Thomas pumps per se are still made, but are sold only for in-line industrial applications.

[Pieter]

I used to use a tank of C02 for my airbrush. No noise whatsoever. I would imagine that should work in the darkroom.

[Drew Wiley]

If you want to study a serious cleanroom operation look at pharmaceutical plants. My wife worked in biotech quality control for about six years. Some of our friends worked in production at the local Bayer plant. All the walls and floors were stainless steel and steam-cleaned before every run. After the workers were all suited up they couldn't open a door until the production run was over, even to go to the bathroom, or the entire batch had to be rejected (at an average cost of about a million dollars per gallon). The inspectors came into the room in advance and put on new white gloves. One of them would run his finger around the inside edge of the overhead air cleaner. If his glove picked up any dirt or discoloration at all, someone got fired.

[Drew Wiley]

High pressurized gases require very expensive safety valves on the tanks, prior to a secondary low-pressure regulator. If anyone tells you otherwise, they're playing with a pipe bomb. CO2 isn't an inert gas anyway, so don't see the logic in this case, or the health aspect in a confined space.

[Pieter]

CO2 tanks were used for years in illustrator's and retouching studios. I don't recall ever having heard of an accident involving them. And don't restaurants use them for carbonated beverage dispensers?

[Eric Rose]

I use a scuba tank with a set of regs attached with a nozzle attached to one of the low pressure hoses.