Difference between revisions of "Improvisation"

Latest revision as of 21:18, 20 March 2023

Lab equipment can be expensive, but it's not impossible to use certain household items as lab equipment as replacement. It's possible to replace many things in the lab, from glassware, plasticware, etc. to entire processes, by using common items.

Glassware and other accessories

Boiling chips

Ceramic shards, such as porcelain (unglazed are recommended) can be used as boiling chips.

For better chemical stability, sandpapered glass shards are also better, as they will not react with most reagents (except hydrofluoric acid, fluorine interhalogens, hot phosphoric acid, hot or molten alkali) and degrade less. It's necessary to sandpaper them to create a rough surface, as normal glass is smooth, inadequate for creating a boiling surface. Since the Mohs hardness of glass is between 5-7, you will need very abrasive sandpapers (the black type for example, has silicon carbide, which is adequate), or an abrasive powder like tungsten carbide or diamond dust.

Boiling/anti-bumping chips can also be produced from crushed high-quality quartz geodes after being treated with acid. The rough surface of these actually protects against bumping more completely than many lab-grade boiling chips.

For distillations where the liquid bumps violently, like conc. sulfuric acid, acid-washed sand is suitable.

Büchner funnel

Coffee filter funnels, usually made of aluminium or stainless steel (rarer), found in certain coffee makers can substitute Büchner funnels very efficiently. They are however unsuited when filtering corrosive substances, such as acidic or alkali solutions (the stainless ones are more resistant to the latter), so they are more suited when filtering organic solutions.

Consumable aluminium beaker

Aluminium cans are more heat-resistant than glass beakers, as they don't tend to shatter on intense heating. The top can easily be removed with a can opener. This is not recommended for use with oxidizing compounds. Large hollow aluminium capacitors can also be used, and since they're thicker than aluminium cans, they deform less when heated. It should be noted, though, that aluminum will react with many acids, sodium hydroxide, and many solutions of metal ions, such as copper(II). Therefore, aluminium beakers are more useful in organic reactions and somewhat useful when dealing with nitric acid. One must be careful when using nitric acid however, since any traces of chloride ions in the presence of acidic protons will dissolve the aluminum. Since aluminum does not have a high melting point, it can melt if overheated.

Cork ring stand

By drilling holes through a series of carefully cut cork stoppers, you can make a very cheap and effective cork ring stand. Here's a good example of such cork ring.

Used cardboard rings cut from wide rolls of scotch tape are also good replacements for cork ring stands. You can also add multiple smaller cutout rings inside a larger one, for better stability. Longer and larger cardboard hollow tubes can be used to make larger RBF stands, and one can find such cardboard tubes in most hardware stores.

Crucible

For most chemical reactions, any steel can can be used as a crucible, though it usually can only be used once before severely rusting. Carefully cut fire extinguisher cylinder bottoms are thicker and better than most iron cans. Stainless steel cups can handle high temperatures much better and will not rust, though they will suffer heat coloring. Any cup-like object made from stainless steel, such as bowl cups, ash trays, can be safely used as crucibles, up until 1000 °C, depending on the grade. Avoid using oxidizing flame, as it cause the metal to rapidly corrode.

For higher temperatures, ceramic flower pots can be used as a vessel for igniting thermite, though they may crack most of the time due to the thermal shock.

Crystallizing dish

Glass oven plates or baking dishes can be used as crystallizing dishes, although it's best to use a smooth surface dish, as dishes with complex inner texture will trap crystals, which makes removing them difficult, as well as difficult to properly wash. Simple dish plates, be it glass or enamel porcelain can also be used if their inside surface is smooth.

Microwave glass turntable plate is also a good choice, as it has a smooth surface and it's wide, giving it a large evaporating surface.

Desiccator

Any plastic or even metal boxes than can be sealed airtight can be used as a desiccator. Large air-tight plastic storage bins, such as this one, available at many stores and hypermarkets are cheap and can be easily made airtight. Normal plastic boxes can be made (somewhat) air tight by adding grease where the lid touches the box, or simply sealing the box using duct tape (though changing the tape when opening/closing the box eats time).

Instead of a plastic box, large reclosable bags can also be used. If the bag is too small, you can cut the bottom of two bags and tape them both. This improvisation also has the advantage of allowing two openings, where one can be used to introduce the wet material, and the other for the desiccant. While cheap, the main disadvantage of this method is that the bags are easy to accidentally poke, which can ruin the dry atmosphere inside.

Dewar

Various all-polystyrene caped cups, boxes and other containers can be used to store cryogenic materials, usually best used for storing dry ice. The thicker the styrofoam walls are, the better it insulates. Some can be found in certain stores, such as hardware stores or in school/office supplies stores.

Double wall stainless steel ice buckets can be used as open dewars, though their use is limited, and can mostly be used for cooling baths. They are generally unsuitable for storing liquid nitrogen and have limited use for dry ice.

Distillation kit

A solvent can (like the kinds used to store acetone, methyl ethyl ketone, and n-heptane) can be attached to a metal pipe, bent over into a collecting vessel. These kind of metal retorts are actually preferable to glass for producing and collecting substances such as benzene and phosphorus. The main problem is their tendency to react with products. One may have trouble with the production of metal chlorides, nitrates, or various coordination complexes if the reagents to be distilled react with the apparatus.

If you do have access to glassware but not to running water, there is a few ways to improvise. The simplest way is to connect an air-cooled condenser such as a Vigreux column instead of a normal condenser. This works best for high-boiling liquids (and for the very high-boiling ones such as sulfuric acid, this is indeed the best option even if you have running water). Another method is to use a water pump in a bucket.

Dropper

For most liquids, a drinking straw may be used as a dropper. Placing a finger on the top opening while the bottom end is under the surface of the liquid allows the straw to be lifted from the liquid while retaining the liquid inside the straw.

Filter paper

Coffee filters are sufficient, unless you need smaller size pores. Colored coffee filtered may however interact with certain organic solvents. Tea bags are also good and have high wet strength. Note that filtration through tea bag paper is quick and dirty, leaving the finest particles in the filtrate. A simple kitchen paper towel is good enough for most filtrations, as they tend to be made out high quality cellulose.

Alternatively, cotton can be used to filter dirty material, usually in a syringe. Air filters can also be used as a last resort.

Gas dispersion tube

Aquarium CO₂ sintered glass bubblers/diffusers can be used to disperse a gas in a liquid, best if said liquid is in a beaker or Erlenmeyer flask. A PTFE tube can be used to connect to the glass bubbler, as it is chemically inert and will not contaminate the solution.

Ingot mold

Cast iron or stainless steel muffin trays can be used to cast circular ingots of metals such as lead, tin, zinc. Other type of metallic trays can be used.

Light bulb flask

Carefully cut light bulb glass can be used as a flask, and is quite resistant to heat, though being very thin means it can break very easy and it might not be able to safely contain a stir bar. High pressure sodium bulbs however are much thicker and may be used just like any other piece of glassware.

Pipeclay triangle

Three thin ceramic tubes are connected with three steel, stainless steel thick wires, though nichrome or kanthal can also be used, inserted through the tube. Alumina tubes, found in various machinery or electric components can be used.

Pipette jar

Any graduated cylinder can be used as a holster for pipettes, best when washing them. Likewise, any tall beaker can used to hold pipettes. Just make sure they're always clean.

If you don't want to use your graduated cylinder for that, you can always glue a long plastic or glass tube on a flat surface with a chemical resistant adhesive and use that as a makeshift pipette jar.

Pencil holders can be used as a last resort.

Retort stands

Upright paper towel holders can be used as lab stands. Generally they are made from either wood, plastic or stainless steel. These stands tend to have better performance than the common lab stands and the stainless steel ones are less prone to rusting than their plain carbon steel counterparts. Their main disadvantage is the short length of the metal rod (~30 cm), which limits their use in large and complex installations. Their base is also not always very wide, which makes them prone to toppling.

Lamp stands with straight tube, such as floor lamps, can be used as retort stands (once you've removed the lamp), though on some models the tube too thick for the bossheads to fit. Since the tubes are hollow, they will deform upon repeated used. A good idea would be to fill the hollow tube with a hard material, like cement or some hard adhesive. To further increase the stability of the stand, a lead weight can be placed on the stand's foot.

Scoopulas

One type of tool used in jewelry making and repair resembles a scoopula. It is available at Hobby Lobby for 50 cents. Various spoon-like plastic-ware from ice-cream shops may serve well as replacement scoopulas. Small scoopulas may be made from straws or pipes with L-shaped cuts at their ends.

Stir bar retriever

A very simple stir bar retriever can be made by adding a small magnet on the bottom of a long glass (or plastic) tube. You can seal the tube to prevent any reagents from touching the magnets or accidentally losing the magnets. If you have a broken volumetric pipette, you can use a gas torch to cut one end near the pipette bubble and seal it. Through the other tube, insert crushed pieces of magnets bit by bit. As the magnet pieces pile up in the glass bubble, they will stick to each other forming a large mass, which cannot fall back through the glass tube. Sealing the tube is optional in this case. This method can also be used for plastic Pasteur pipettes.

Stirring rods

Glass bead kits often come as glass rods, which can be used out of the box. Alternatively, you can make one by sealing a glass tube from a broken pipette at one or both ends.

Test tube holder

Large clothespins can be used as tube holders. If their cutaway section is too small, it can be widened by carefully cutting it or simply cutting a new one.

Test tubes

Vanilla pods are often sold in glass tubes with a plastic lid. Similar tubes are also found in many bargain stores, as containers for incense sticks. Usually there's two of them, bound with a sticker.

Plastic or glass test tubes can be found in many stores, used for storing flavors, spices, as well as many other non-edible products, such as toys. Martha Stewart test tubes are a good example. Test tube shots can sometimes be found in many clubs, bars and pubs, used for shot drinking.

Many brads, such as Jägermeister, not only sell plastic cylindrical shot tubes, but also other types, such as rectangular tubes and even tube racks of various sizes, made either from foam, metal, plastic or acrylic. Other alcohol product companies sell similar products.

It is important to remember that most of these glass test tubes do not handle thermal shock as good as lab test tubes.

Wash bottle

A bent plastic tube inserted in a relative thick plastic bottle works pretty good as a wash bottle. Normal plastic bottles can also be used, though their performance varies.

Some RC fuel bottles can also be used as wash bottles.

Watch glasses

Literal glasses from watches or clocks can be used as watch glasses. Most however tend to be flat glass disks, and may pose problems when holding spherical particles. They are also not heat resistant. Eye protection goggles lens display identical features.

Carefully cut wine glass bottoms can also be used, though you will have to flatten the wine glass leg stub, best to use a suitable bench grinder. Another idea is to make a support out of epoxy to keep it straight.

Small glass plates/dishes can be found in many stores and are very cheap.

None of the above however have good thermal shock resistance, though they are good enough for recrystallization.

Plastic watchglass can also be made from various concave appliances parts or coverings. An example is the circular type of display screen cover, used for portable CD players. Leaving it in a sodium hydroxide solution overnight will remove most of the outer paint, especially if it's silvery aluminium. Do not leave it too long in sunlight or it will become brittle.

Wire gauze

A stainless steel or nichrome mesh can be used. A sheet of heat-resistant material, like mineral wool or asbestos can be added in the center of the mesh.

Conveniences

Büchner funnel

One SM user build a makeshift vacuum filtering funnel by placing a simple glass funnel with a filter paper through a glass bushing adapter with screw cap, which is connected to an adapter with side arm.

Dean-Stark apparatus

A replacement for a Dean-Stark apparatus can be made by assembling a distillation setup, with a Claisen adapter, where a hose adapter is placed on the second opening, and a long glass tube or another condenser (not connected to cooling), between the Claisen adapter and the still head, to increase the distance between the two. To the still head, a water cooled condenser is connected, where the crude distillate condenses and drips in a graduated cylinder below. A chemically resistant plastic tube it inserted to the cylinder, with the end positioned half-way, the siphoning tube continues near the bottom level of the cylinder, then rises up and connects to the hose adapter from the Claisen adapter of the distillation setup. Secure the tube on the top of the cylinder using a clip. Since this setup requires siphoning to work, it must be properly aligned and the graduated cylinder must be filled to work. Likewise, make sure the position of the siphon tube inlet is below the outlet relative to gravity. Fill the graduated cylinder with toluene or the lighter phase liquid, through the hose adapter then place it back on the Claisen adapter. Begin the distillation of the liquid mixture. The vapor front cannot move upwards through the plastic tube into the graduated cylinder, but it will rise through the tube and condense in the condenser and fall in the graduated cylinder. The heavier phase (water in this case), falls to the bottom of the cylinder, while the lighter phase will siphon back in the distillation flask. This setup can be used to return the lighter phase from the system, but if you want the heavier phase of the dual system, all you need to do is replace the lighter phase (toluene in this case) from the siphon tube with the heavier phase (water) and lower the inlet tube all the way to the bottom of the graduated cylinder, while also lowering the middle of the siphon tube to a position lower than the foot of the cylinder tube. The heavier phase will siphon back in the distillation flask, while the lighter phase will accumulate in the cylinder. Watch NurdRage's video here.

Household appliances

Coffee grinders can be used to grind soft materials, and with slight modification can also be used to make metallic powders.

Clothes iron may be used as a makeshift hotplate.

Electric fans can be used to blow air or cool solutions.

Hand mixers can be used to dissolve non-corrosive compounds into solutions or stir suspensions.

A heat gun is a cheap and convenient source of flame-free heat, useful to melt or heat various substances. Hair driers may also be used, albeit they produce less heat than heat guns, meaning their use is more limited.

Icecream makers can be used to make ice.

Kitchen scales can be used as weighting scales.

Microwave ovens can be used to make plasma for scientific demonstrations.

Range hoods can be used as cheap fume hoods, but they aren't suitable for extracting corrosive vapors and they lack chemical resistance.

Refrigerators and freezers can be used to cool materials, and are very useful when recrystallizating compound out of a solution.

With proper modification, a vacuum cleaner can be converted into a modest vacuum pump.

Miscellaneous

Heating elements

Kitchen stoves, portable cooking/camping hotplates, alcohol burners, and even candles can be used for simple reflux setups or dissolving solutes. A metal plate or grate can be placed over a well-controlled fire to obtain very high temperatures, which may however break glass. A sand or an oil bath can be placed on the metal plate. When boiling flammable solvents, avoid using an open flame.

Microwave ovens can also be used for heating chemicals directly and more homogeneous.

Storage containers

Ordinary food glass jars can be used for storing many compounds, however, they are unsuitable for storing volatile compounds, as the lid, usually enameled or painted metal is not resistant to corrosion and may contaminate the compound with rust. Use plastic lids instead, such as PP or PE.

Metal coffee containers, such as the ones used for coffee, cocoa, tea, cookies can be used for storing non-hygroscopic and non-corrosive compounds. Since they tend to be airtight, they can also be used to store moisture or air sensitive materials, such as carbides, alkali and alkaline earth metals, metallic powders, flammable compounds, etc. Empty metal paint cans are also suitable for this task. Stainless steel food containers can also sometimes be found at hypermarkets and are good for storing various materials, such as solid compounds and some salts, except for corrosive ones.

Old large siphon/soda bottles are a good choice for storing volatile chemicals, due to its narrow opening, large body volume and can tolerate high pressures. They can be used to store volatile corrosive chemicals such as fuming acids, liquids with low boiling point, etc. A PE, PP or even PTFE lid (if you have one) can be used to close the opening.

Any container that originally came from the grocery store and contained food must be appropriately relabeled; the old label completely removed and a new one, warning about the hazards of the compound within, glued to it. Nothing about the container is allowed to say "Eat me!". This requirement is less strict with containers that originally held inedible stuff, such as topical medications or household chemicals.

Water aspirators

For vacuum filtering, Venturi injectors, available at agricultural shops, can effectively replace lab water aspirators.

Smaller Venturi injectors can be found in aquarium shops, though they are generally too small for performing strong vacuum.

Video

A significant portion of the ideas came from myst32YT's video of lab tips:

References

Relevant Sciencemadness threads

• Laboratory Tips and Tricks
• Homemade and Repurposed Lab Gear
• Improvised DIY homemade glassware
• Ingenious glassware applications
• Light bulb flasks