Find all your DIY electronics in the MakerShed. 3D Printing, Kits, Arduino, Raspberry Pi, Books & more!

MAKE_sci_GEN_190px.gif

This article is based on material originally published in 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.

 

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.

You can buy the items you need individually or as part of kits sold by most lab equipment suppliers. Maker Shed offers a basic kit that includes the items mentioned in this article, as well as a few other kits that supplement the basic kit.

Comments

  1. Cynthia says:

    What would you recommend in the way of a digital scale for intermediate/highschool science? I was thinking of purchasing one that was a 1000 g capacity with a 0.1 sensitivity. Could this both serve chemistry and physics, etc.?
    Thanks,
    Cynthia

  2. Bob Thompson says:

    Hi, Cynthia

    Good question. The two big trade-offs in buying a balance are capacity and resolution. Ideally, we’d all like an inexpensive balance with 0.0001 gram resolution, but unfortunately there aren’t any such animals.

    The balance I chose two or three years ago for my own home lab is the desktop MyWeigh iBalance 201, which has 200 gram capacity and 0.01 gram (centigram) resolution. That’s still a current model, and is available in Maker Shed and elsewhere. However, it’s also a $100+ balance.

    If you’re looking for something a bit less pricey, Maker Shed also carries a portable $33 electronic balance (on sale through 10/31 for, IIRC, $28) that has the same 200 gram capacity and 0.01 gram resolution. I have one of those as well, and it’s a very nice little scale. I suspect it probably isn’t quite as durable as the i201, but OTOH it’s less than a third the price. (It’s also useful around the house. My wife just used it yesterday to see if she needed to put a second stamp on an envelope.)

    My take on this is that 200 g is sufficient capacity. Almost any experiment you do that would use the 1000 g capacity of the balance you’re considering can be scaled down to work within the 200 g capacity of these balances. OTOH, having 0.01 g resolution instead of 0.1 g resolution is very nice, particularly for chemistry.

    It’ll also save you money on chemicals. For example, if you need to make up a solution to a particular accuracy, being able to weigh out (say) 7.87 g of the chemical and making up 100 mL of solution is cheaper than having to weigh out 78.7 g of the chemical and make up 1,000 mL of the solution.

    RBT

  3. Sacha says:

    Hi Bob,

    This is a great list, but I’d like to disagree with a few of your equipment choices – I’ve been a chemical researcher for years, and have had my own basement lab for some time, but there’s a few things here that I’d never use for safety, ease of use, and cost reasons.

    First off – test tubes. I don’t really think these are useful for anyone except for hollywood, high school chem labs (the last time I used one), and a few specific analytical tests that are unlikely to be run in a home lab. Test tubes are fragile, can’t be set down, and require tons of accessories (special tongs, racks, cleaning brushes, etc). I’d much rather use a small flat-bottomed vial. Vials are stronger, have a screw-on cap, can be set onto a hot plate without requiring a stand, and can be set on a counter quickly (useful in case a problem arises!). I use vials for nearly all my small scale reactions – I’d never use a test tube.

    Another place you can easily save money and fiddlyness is in your small graduated cylinder. While a large graduate cylinder is necessary for measuring liquids for dilutions or large scale experiments, small graduated cylinders can all be replaced by oral syringes. Go to your local pharmacy and ask (nicely) for an oral syringe – they’ll happily give you a few for free. You can more precisely measure and deliver a volume using an oral syringe than a graduated cylinder (just make sure you have a little bit of air over the liquid so you can see a meniscus!). And since it’s free, there’s no worries about ruining it.

  4. Bob Thompson says:

    Hi, Sacha

    As I’ve said before, I learn something new every day…

    I’d never thought of using borosilicate glass vials as replacements for test tubes, but that’s an excellent idea. I use test tubes fairly frequently, for everything from small-scale reactions to storing specimens, but I’ll order in a few vials and try them out. I’ve also found I often use a reaction/spot plate instead of test tubes, which is why I included one of those in the set.

    Of course, the rounded bottom of test tubes does confer some advantages, notably ease of cleaning out gunk. As you say, test tubes do have a place in high school chem labs, and since home schoolers doing high-school chemistry are a large part of our readership I think I’ll leave test tubes on my recommended list.

    As to the oral syringe, that’s another good idea, assuming one can find them cheaply. I actually visited the local Walgreens when I was writing the chemistry book to find out what useful chemicals and gear I could find there. They had oral syringes, but they wanted something like $3 each for them.

    RBT

  5. Sacha says:

    Hi Bob,

    My favorite vials are scintillation style vials – they’re 20mL borosilicate glassm come with white urea caps and have several different cap liners available, I find that the polyethylene disc (not the cones) liners work best for me:
    http://www.coleparmer.com/catalog/product_view.asp?sku=0891805
    They’re $229 for a pack of 500.

    I was introduced to them years ago as an research intern and haven’t found anything half as useful since then, and at about $0.50 to $0.75 per vial, you can’t get a much more cost effective solution.

    You can also get this style of vial in a crystal clear PET and HDPE resin, but neither will be heat resistant.

    Actually, if the Make science room sold these in smaller batches (say in packs of 50) I’d certainly buy a bunch for my personal lab (hint, hint).

    As for the oral syringes – it surprises me that you couldn’t get them cheaper than that. At they were more than happy to just give me a couple for free…

    1. Bob Thompson says:

      Thanks, Sacha.

      After I read your post yesterday, I checked with the half dozen or so wholesalers that we have accounts with and purchase lab equipment from. None of them carries scintillation vials or anything similar. I suspect that’s because all of them focus on the science education market, and there is apparently little demand from schools for these products.

      Still, our wholesalers often carry items that aren’t in their catalogs, and they can often get items like this from their own suppliers. I’ve emailed queries to them to find out if we can get vials from them.

      Thanks for the recommendation.

      RBT

  6. crow says:

    I was able to buy a job lot of 100 syringes from a popular auction site here in the UK.

    Cost was around £8 inc postage. 10ml sized. with accurate grading on the side. Medical quality and each individually wrapped. Sadly come with needles too, so have to safely dispose of those. But found a million uses for the syringes.