In the Make: Online Toolbox, we focus mainly on tools that fly under the radar of more conventional tool coverage: in-depth tool-making projects, strange, or specialty tools unique to a trade or craft that can be useful elsewhere, tools and techniques you may not know about, but once you do, and incorporate them into your workflow, you’ll wonder how you ever lived without them. And, in the spirit of the times, we pay close attention to tools that you can get on the cheap, make yourself, or refurbish.
I thought, for Citizen Science month, I’d reproduce the first two installments of this piece from the Make: Science Room. It is based on material originally published in the awesome Make: Books title Illustrated Guide to Home Chemistry Experiments: All Lab, No Lecture, by Robert Bruce Thompson, and the not-yet-published Illustrated Guide to Forensics Investigations: Uncover Evidence in Your Home, Lab, or Basement, by Robert Bruce Thompson and Barbara Fritchman Thompson. The final article in the series, “Chemicals on the cheap,” can be found here.
As is true of most hobbies and other organized activities, if you’re going to do home science, it’s desirable to have a dedicated place to do it. But dedicated lab space is by no means essential. After all, when most people think of home science the image that comes to mind is a kid working with a chemistry set at the kitchen table. Even if the kitchen table is the only available place to work, you can get a lot of home science done.
But before you settle on the kitchen table, give serious consideration to other possible locations for your home lab. Of course, you may have to choose between using the kitchen table and having no lab at all. In that case, do the best you can with what you have to work with. Here are some things to think about when you choose a location for your home lab.
Even microscale experiments require a surprisingly large amount of workspace. In addition to space for the experiment setup itself, you’ll need space for your balance, your microscope and supplies, your lab notebook, temporary space for any chemicals that you are using, and so on. Consider 10 square feet (1 square meter) of counter or table space as an absolute minimum, and more is better. The ideal setup is arranged like a photographic darkroom or galley kitchen, with a wet side and a dry side. The wet side is used for doing the actual experiments, and the dry side for storing and weighing chemicals, recording observations in your lab notebook, and so on.
Protecting Work Surfaces
Some of the chemicals you work with may stain or otherwise damage wooden or laminate work surfaces. We protect our work surfaces, which are standard kitchen laminate counters, by covering them with rubber non-slip mats that are available in various sizes and thicknesses at craft stores. We also put an old bath towel between the counter top and the rubber mat. The mat provides a smooth, level, chemically-resistant work surface, and the old towel absorbs any liquids that run off the mats.
Our advisor Dr. Mary Chervenak is an expert on paints and coatings. We asked her and another advisor, Dr. Paul Jones, if there was any kind of paint that could be used to protect surfaces from most laboratory chemicals. The short answer is “not really.” Standard latex, polyurethane, and epoxy-based paints and coatings offer reasonably good protection against many reagents and solvents, including the dilute reagents used in most of the experiments in this book. However, they offer less (or no) protection against strong acids or bases or some organic solvents.
Still, as Dr. Jones commented, some protection is better than none, and in a sense you can think of these paints as ablative coatings. The coating itself may dissolve in or be eaten away by a strong chemical, but it may protect the underlying surface long enough for you to dilute, mop up, or neutralize the spill. If we used a wooden workbench or a similar surface, we’d put several thick coats of an epoxy-based deck or floor paint on it, and then protect it further with a rubber mat and towel.
Even if you take reasonable precautions and work carefully, it’s almost inevitable that at some point you’ll spill something nasty on your work surface. That’s a good argument for choosing a work surface that’s expendable. If you eat holes in a sheet of plywood or particle board, that’s cheap and easy to replace. If you eat holes in your washer/drier, you may have some explaining to do.
Segregate toxic, flammable, reactive, and corrosive chemicals into separate containers or cabinets according to their storage color codes. Gladware, Tupperware, or Rubbermaid kitchen storage containers are available in various sizes, are made of chemical-resistant plastic, and have sealable lids. They’re an excellent choice for segregating your chemicals by type. You can also use heavy zippable plastic freezer bags to isolate individual chemicals or compatible groups of chemicals within a larger storage container. (Yes, Figure 1 shows some extremely toxic chemicals, which I purchased while I was working on the home forensics book.)
Figure 1. Store hazardous chemicals segregated by type with other compatible chemicals
If at all possible, keep your microscope and its supplies in a work area separate from where you do wet chemistry. For example, our main lab is in the basement, but our microscope is set up on a second desk in my office upstairs.
Some experiments produce smoke, strong odors, or even toxic fumes. It’s important to have some means of ventilating the work area and exhausting these fumes to the outdoors. The ideal solution is a formal laboratory exhaust hood, but an open window with a portable exhaust fan can often serve the purpose. For experiments that produce a lot of smoke or fumes, work outdoors.
It’s dangerous to work in a poorly-lit environment. As a teenager, my first home lab was located in a dark corner of the basement, and I had more than one near-accident before I installed some fluorescent fixtures. Make sure your work area is well lit. If the overhead lighting is inadequate or nonexistent, use table lamps, clamp lamps, or other portable light sources.
You can get along without electricity other than for lighting, but it’s very convenient to have one or more electric receptacles within easy reach of your work surface. If those receptacles are not protected, install ground-fault circuit interrupters.
Water and sewer
Although it is not essential, it is extremely convenient for the home lab to have access to running water and a sewer connection. If that’s not possible, acquire a large bottle to use as a water supply. The 5-gallon plastic carboys used in water coolers are ideal, but you can substitute recycled 2-liter soda bottles. With a stopper, some tubing, and a pinchclamp, you can build a siphon to deliver water as needed. Use a large plastic bucket, tub, or similar container for waste liquids, and empty it after each lab session.
Even if you are extremely careful, sooner or later you are bound to spill something. Murphy’s Law says that what you spill will be corrosive or strongly colored, and will fall exactly where you don’t want it to fall. If the floor is carpet or another vulnerable material, your spouse, parents, or significant other will not be amused. Sheet vinyl or linoleum is the best flooring material for a home lab, although vitreous tile and similar resilient materials are also good. If the floor is concrete, consider painting it with epoxy-based floor paint to prevent it from being stained or absorbing spilled chemicals.
We have a seldom-used second kitchen in our basement guest suite, which is an ideal home laboratory. Not everyone is lucky enough to have a room or even a corner that can be dedicated to a laboratory. Fortunately, there are many alternatives.
Let’s get this one out of the way first. The kitchen may seem to be an ideal location for a part-time laboratory. There’s usually plenty of counter space and storage, hot and cold running water, good lighting, plenty of electrical outlets, resilient flooring, and the exhaust fan over the stove can serve as a field-expedient fume hood. In fact, unless you limit yourself to using only nonhazardous chemicals, the kitchen is about the worst possible choice for a part-time lab. Food and laboratory chemicals are a dangerous combination.
Still, thousands of home labs over the years have been set up in kitchens, and the kitchen may be your only option. If so, take extreme care to prevent any contamination from occurring. Protect the counter or table surface (and, if possible, the floor) with a resilient chemical-resistant mat, and clean up thoroughly after each lab session. Make sure that all of your equipment and particularly your chemicals are returned to their storage containers and that none are missing.
Many laundry rooms are ideal candidates for a part-time lab. Laundry rooms are usually well-equipped with electric power, water, drain, lighting, and have adequate ventilation. There is often sufficient storage and if not it’s usually easy to add more. There is probably a suitable work surface available, and if not it’s usually easy to add a fold-down or other temporary work surface. The floor of most laundry rooms is concrete or vinyl, which minimizes the danger of damaging it with spills. In most homes, the laundry room is the best choice for a part-time lab. Of course, you have to clean up carefully after each lab session to avoid the risk of staining or damaging clothes.
A spare bathroom is often an excellent location for a part-time laboratory. It provides running water and a drain, plenty of electric receptacles (with ground-fault circuit interrupters), good lighting, and good ventilation. Many spare bathrooms are a bit short on storage and counter space, but that’s often easy to remedy simply by constructing a collapsible framework that supports a plywood work surface over the tub. Particularly if you live in an apartment, a spare bathroom may be the best choice for a part-time lab.
A basement workshop area is generally not an ideal location for a part-time lab, but may be the only option. On the plus side, storage and work surfaces are usually not a problem, the floor is often of concrete or another relatively impervious substance, and electric power is usually available. However, ventilation is often inadequate, and many basements have no water supply or drain.
Garage or garden/storage shed
For some people, the garage or garden/storage shed will be the location of last resort. There are some good points to using such a location as a part-time lab (or even a full-time one). Storage and work surfaces are usually plentiful or can easily be made so, ventilation is often adequate, there is usually electric power available, and spills that damage the floor or work surfaces are of less concern than they would be in a finished area of the house. Weighed against this, it may be a long trek to the nearest sink and drain (although you may be able to use the garden hose as a water supply). Perhaps the worst aspect of using such a location is the lack of climate control. You’ll swelter in the summer and freeze in the winter. Even if you can tolerate that, it’s not the best environment for storing your equipment and supplies or for doing controlled experiments.
If your work area is not heated and air conditioned, give some serious thought to chemical storage. The shelf life specified for many chemicals assumes storage at normal room temperature. Allowing a chemical to bake in the summer heat of a storage shed or garage may reduce that shelf life from a year or more to a few weeks or even days. Less obviously, storing some chemicals at low temperatures may be a bad idea. Glacial acetic acid, for example, freezes at 16.7°C (62.1°F), and the solutes in solutions that are nearly saturated at room temperature will crystallize out at low temperatures. More importantly, some chemicals that are reasonably stable at room temperature may decompose or become unstable if they are stored at high temperature.
Finally, I thought you might like to see some images of our home lab, where we do chemistry, biology, earth science, forensics, and physics work. If it looks like a kitchen, that’s because it used to be the kitchen in our guest suite. Now that the kitchen has been permanently converted to lab space, overnight guests just have to use the main kitchen. Oh, well.
Figure 2 shows one of a dozen or so cabinets and drawers that are devoted to storing glassware and other equipment. We make it a rule to wash, dry, and put away all glassware and other equipment when we complete each lab session. (Although I am notably sloppy otherwise, I am an absolute neatnik when it comes to keeping the lab clean and organized.)
Figure 2. Glassware storage cabinet
Figure 3 shows one of several cabinets that are devoted to chemical storage. This cabinet is used for general nonhazardous chemical storage, but also for small quantities of some chemicals that present only moderate hazards (no more than 125 g or 125 mL of each). Concentrated strong acids, strong bases, strong oxidizers, and other more hazardous materials are stored in separate cabinets.
Figure 3. One of several chemical storage cabinets
Figure 4, which Barbara originally shot as an illustration for an article in Chemical and Engineering News about home labs, shows me titrating an oxidane1 sample with a concentrated solution of hydric acid2. Note that I am wearing full protection, including splash goggles, gloves, and a lab coat. (Before Barbara shot this image, she mentioned that my hair was a mess. I pointed out that it almost always is, so why change things?)
Figure 4. Me running a titration in our home lab (note the goggles, gloves, and lab coat)
Figure 5 shows Barbara examining a specimen at our microscopy work station. We keep our microscope set up on a side desk in Robert’s office, with related equipment and materials immediately at hand. That has two advantages. First, the microscope is safe from exposure to chemical spills and other hazards present in the main lab. Second, the digital camera we use to shoot photomicrographs can remain permanently connected to my main desktop PC, making it fast and easy to transfer images. If at all possible, we recommend you also keep your own microscope and other expensive optical equipment away from your main lab work area.
Figure 5. Barbara examining a specimen at our microscopy work station
This is our lab setup, which we’ve tweaked over the years, and it works well for us. It’s more elaborate than most home labs, of course, but even if your own space and other resources are very limited, with a little thought there’s probably a great deal you can do to organize your own setup to make it as safe and efficient as possible.
1oxidane is another term for water
2hydric acid is another term for water
Part II: Gearing Up
Scientists have a long history of making do with whatever equipment is readily available or easily constructed. (Home scientists’ spouses and parents get used to household objects mysteriously disappearing, but that’s another story.) Most common lab glassware items — test tubes, beakers, flasks, and so on — were invented by chemists to replace the household items they’d been using. For example, while he was working as lab assistant to the great English chemist Humphry Davy, Michael Faraday invented the test tube. Before then, many chemists used champagne glasses as test vessels…and their spouses probably wondered where all the champagne glasses had gone.
These days, things are even easier for the scientist-scrounger than they were a century or two ago. We have treasures they could only dream about, including cheap, heat-resistant Pyrex kitchen measuring cups, disposable soda bottles made of chemical-resistant plastic, cheap filter paper and chromatography paper (bleached paper coffee filters), inexpensive hotplates, and so on. In fact, you can get a good start on equipping a home science lab using items from Wal*Mart, Home Depot, or similar retailers.
But doing real science at home requires some specialty items that are difficult or impossible to substitute. My editors at MAKE asked me to make a list of essential specialty lab equipment that every home scientist needs as a “starter kit” to perform a wide variety of experiments in chemistry and the other sciences. So I sat down to think about which items would provide the most bang for the buck. Here’s what I came up with:
- Goggles – Although you can buy protective goggles at any hardware store, they are intended to protect against particle impact hazards, not chemical splashes. So, as the first and most important item, you need to purchase laboratory-rated chemical splash goggles.
- Test tubes and accessories – It’s hard to imagine a science laboratory without test tubes. They have dozens of uses, from running small-scale reactions to storing solutions or specimens to generating or capturing small volumes of gases. A half dozen test tubes is a good starting point. You’ll also need various accessories: a test tube rack, test tube tongs, and a test tube brush. Buy at least one solid and one one-hole rubber stoppers to fit your tubes
- Beakers – Although you can sometimes substitute other containers, every home science lab needs at least one or two real beakers, if only for heating solutions. The most useful sizes for a home science lab are 150 mL and 250 mL.
- Flask – An Erlenmeyer (conical) flask has many uses around the lab. The most useful size for a home lab is 250 mL. You’ll also want a two-hole rubber stopper to allow the flask to be used as a distillation vessel or gas-generating bottle.
- Graduated cylinders – Graduated cylinders are essential for measuring liquids accurately. The most useful sizes for a home science lab are 10 mL and 100 mL.
- Alcohol burner and burner stand – Although liquids in a beaker or flask can be heated safely on an electric hotplate or kitchen stove burner, there are times when the higher temperature of a flame-based heat source is needed. An alcohol burner has been the traditional heat source in home labs for more than a century, and it remains a good choice today. Buy a modern safety alcohol burner as well as a burner stand to support the vessel being heated.
- Thermometer – A good lab thermometer is essential for any lab work that involves thermochemistry or calorimetry, and is often needed for simple procedures such as distillations, making up solutions, or managing a reaction.
- Polyethylene pipettes – These beral-type pipettes are made of chemical-resistant plastic, and can be re-used over and over simply by rinsing them thoroughly after each use. In addition to their obvious use for transferring liquids, these pipettes can be calibrated volumetrically (with a graduated cylinder) or gravimetrically (with a balance) and then used dropwise to transfer measured liquid volumes very accurately. With scissors, you can convert one of these pipettes into a small chemical scoop or a small filtering funnel. Buy a pack of five or ten pipettes.
- Reaction plate – A reaction plate is a rectangular chemical-resistant plastic vessel with an array of small wells. It’s ideal for testing one or several specimens against one or several reagents, and because it uses much smaller volumes than test tubes, it helps economize on expensive chemicals. Cleanup is also a lot faster if you have only one dirty reaction plate instead of many dirty test tubes. Buy one of the 24-well polystyrene models with a lid. Be careful using it with organic solvents, which can damage it.
- pH test paper – It’s often important to test the acidity or basicity of a solution. The old fashioned answer in home labs was using litmus paper, which provides only a general indication of acidity or basicity. Rather than litmus paper, you should buy a vial of pH test paper that allows you to determine a numeric value for the actual pH of a solution.
- Small accessories – You’ll also want various small useful items: a funnel, stirring rod, glass tubing, heat-resistant flexible tubing, and a Mohr pinchcock.
We suggest you buy high-quality student-grade equipment rather than professional grade. The student grade is perfectly acceptable for home use, and costs much less. Don’t make the mistake of paying too little, though. There’s some real garbage out there, and it’s cheap in every sense of the word.
For example, a professional-grade Pyrex or Kimax beaker might cost $5. A similar beaker from one of the good brand-name Asian manufacturers (Bomex, Borosil, or Premiere) might cost $2.50. A no-name Chinese-made beaker might sell for $1.50. As our friend and technical adviser Dr. Paul Jones put it, if you subject 100 of the Pyrex or Kimax beakers to a strong direct flame, one of them might shatter. If you do the same with 100 Bomex, Borosil, or Premiere beakers, two of them might shatter. If you do the same with the no-name Chinese-made beakers, all of them might shatter.
To see the final part of this “Setting up a home science lab,” see “Chemicals on the cheap,” in the Make: Science Room.