Is Wood a Conductor

As the use of electrical appliances has increased in the kitchen, it has changed the kitchen itself. No longer do most people cook over fire, with electric ranges largely having replaced gas ones. Tedious tasks which used to be done by hand are now accomplished through the use of small appliances. More and more cooking tasks are becoming automated, increasing the electrical use in the kitchen.

This raises concerns, because kitchens also have a lot of water, which is normally considered to be a good conductor of electricity. We’ve all heard stories about someone who got shocked to death from using a hair dryer in the bathtub. While most of those stories are just that, stories, the fact of the matter is that it is possible for something like that to happen.

Actually, it’s not water that conducts electricity so much, as the salts and minerals in the water. While water does have some electrical conducting capability, it is minor. On the other hand, most minerals, especially metals, are excellent conductors of electricity.

Electricity, as we know it, is the flow of electrons or ions from one molecule to the next. Some elements naturally do this well and some don’t. When we are creating workspaces for ourselves and our families, using materials which are not good electrical conductors makes for a safer work environment. Therefore, knowing which materials conduct electricity well and which ones don’t helps us to create a better kitchen, bathroom, workshop or furniture.

Materials that don’t conduct electricity are considered to be “insulators. But not all insulators are perfect insulators. That’s because like water, they are rarely pure. Rubber is normally considered to be a good insulator. Even so, car tires are not. That’s because of the addition of carbon black to the rubber, which is a conductor.

Conductivity (the ability to conduct electricity) can be a variable thing. The higher the electrical voltage (also called “potential”) the better electricity can breach any insulation. While the electricity in our homes is not really high voltage, the electricity in our home’s wiring is 120 volts, while the electricity in a battery-operated appliance may only be 12 volts or less. So, there’s a greater chance of electrical shock from that appliance that plugs in, than there is from the handheld one.

So, What About Wood? 

Wood alone does not have much ability to conduct electricity. However, when the wood is wet, then its conductivity increases. Worse than that, the salt and mineral laden water is conductive. So, while the wood itself might not cause electrical shock, the water sitting on the wood can cause that shock.

Most finishes we put on wood help prevent it from being conductive, both because they are good electrical insulators themselves and because they seal the wood’s surface, keeping it from getting wet, varnish, epoxy and latex paint are all good insulators. For that matter, almost all paints are good insulators, although there are paints which have metal additives, like aluminum paint. Those are not insulators and in fact may very well be good conductors.

Oils, such as Tung oil, used for finish wood, are only slightly conductive. So, while they will keep the wood from getting wet, thereby helping to prevent it from conducting electricity, they may very well conduct the electricity themselves. So, they cannot be considered safe.

What About Other Countertop Materials?

Today we find kitchen and bath countertops made of a wide variety of materials. The Formica laminate that was so prevalent in past years is going by the wayside, especially in nicer homes, as other materials are taking its place. Formica and the other similar laminates are basically non-conductive, although there are some versions made for industrial use (especially in the electronics industry) which have metal added, making them conductive.

Corian countertops have probably taken over most of the countertop market, having the dual advantages of being longer lasting and the ability to be refinished. The coloration in any variety of Corian comes from flakes of minerals embedded in the countertop material, which would tend to make us think that it might be conductive. However, those mineral flakes are embedded in Acrylic plastic. Like most other plastics, Acrylic is a good insulator, so unless there is a very high voltage, Corian is an excellent insulator.

Granite and other natural stone materials are even now replacing Corian as the material of choice, especially in upscale homes. The natural look of these stone materials is beautiful, making for very attractive countertops. However, granite does have some capability to conduct electricity, even while dry. This is due to the metal content in the granite. However, marble is considered to be an excellent insulator.

Finally, we find metal countertops, which were traditionally used only in commercial kitchens, finding their way into homes. In addition to stainless steel, copper and zinc are being used. All of these are metal, therefore highly conductive. The normal oxidation that happens to some of these metals can reduce their conductivity, but not to a point where it makes any difference in practical use.

corian, countertop, insulator
Corian countertop insulator, Tina

Protecting Ourselves from Electric Shock

Electric appliances are designed and built with the understanding that they will be used in a wet environment. Great pains are taken to ensure that the cases of these appliances provide adequate electrical insulation to protect the user. There are testing requirements in place, which must be adhered to by government regulation.

So is that enough? In most cases it is. However, there are some possible exceptions. old appliances are likely not built to the standards of today. I have an electric carving knife which was given to my mother as a wedding gift. It still works twice a year, when I use it to carve our Thanksgiving and Christmas turkeys.

However, I am not under any illusions about that utensil. The case is damaged, which means that its insulating capability has been compromised. I’ve solved that problem by covering the crack with a piece of clear acrylic, which has been epoxied in place.

Any break or breach in an appliance’s case should be taken seriously as a potential risk. There is little inside any kitchen appliance which does not have electricity flowing through it. Therefore, appliances which have been broken should be replaced, or if they have sentimental value, then at least repair the case, so that there is nothing exposed.

Watch out for electric cords on these appliances. There is a greater possibility of the insulation on them becoming cut, nicked, crimped or crushed, than the case of the appliance being damaged. If that leaves any wire exposed, there is a danger of shock. Either replace the cord or at least wrap it with electrical tape. I keep a variety of spare cords around, for just this purpose.

Don’t Forget the GFI

Most appliances only use a two-wire electrical plug, even though modern homes are wired with three-wire outlets, providing a ground lug as well. Grounded appliances are safer, in that the ground wire ensures that the electric current from any short inside the device goes safely to ground. However, man appliances only use a two wire cord, doing without the ground wire. In this case, it is possible for a short to create a situation where the user can get shocked.

Current building codes require the installation of GFI (ground fault interrupter) outlets or circuit breakers to be used for kitchens, bathrooms and any other room where there is water present (such as a laundry room). These are there to cause a disruption in power, should a short in the device be detected. The GFI will trip off, like a circuit breaker, protecting the user.

The way that a GFI does this is that it senses any difference in the current flowing through the hot and neutral wires. GFIs are designed so that even a difference as small as 4 or 5 milliamps will cause the GFI to trip, protecting the user.

Although they were not a requirement when older homes were built, GFI outlets can easily be added to older homes, which have two-wire outlets. The GFI outlets do not need to be grounded to work. All that’s required is to remove the old outlet and install the new one. This will provide the necessary protection.

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