Selecting the Right Epoxy ESD / Conductive Flooring

June 15, 2015

Conductive and Electrostatic Dissipative (ESD) flooring are used on floors in facilities that need protection for stray static discharges. One example of static discharge is when you walk across a carpet in a very dry room in winter then touch a metal object or another person you get that little electrical zap. Most people find this a bit of nuisance. However if you touch a hard drive or a circuit board and create that same discharge you can damage it beyond repair. Worse yet if you get a static discharge in a chemical or munitions plant where there might be a potentially explosive environment the results can be a catastrophic explosion.

What is ESD Versus Conductive?

Conductive floors have between 100,000 and 1,000,000 ohms of resistance. Electrostatic Dissipative (ESD) floors have between 1 million and 1 billion ohms of resistance. Remember Ohms Law:

Ohms_Law

where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm’s law states that the R in this relation is constant, independent of the current.

Simply speaking the resistance is the ohms of resistance that we are talking about above. The lower the ohms of resistance the stronger the conductive medium to conduct the static charge away. The lower the ohm of resistance the more efficiently the conductive/ESD flooring carries the static charge safely away. .This is one situation where the smaller the number the better.

How does Conductive and Electrostatic Dissipative (ESD) flooring Work?

Think of your Conductive and Electrostatic Dissipative (ESD) flooring as a grounding rod. A grounding rod is that metal rod that gets driven into the earth to increase the surface area coming in contact with the ground. You then attach your building ground or lightening rod to that grounding rod. The Conductive and Electrostatic Dissipative (ESD) flooring is much like that. It makes the whole concrete surface that the Conductive and Electrostatic Dissipative (ESD) flooring comes in contact with a large grounding plane, acting much like a grounding rod. In some facilities this effect is enhanced even more with the installation of grounding strips that the Conductive and Electrostatic Dissipative (ESD) flooring connects to the grounding rod(s). .

Where do you use Conductive and Electrostatic Dissipative (ESD) flooring?

Typically ESD flooring is used in areas to protect electronics. Conductive is more commonly used where there is the potential for an explosive environment. Most facilities that require ESD flooring can use conductive flooring as well. The reverse is typically not true. Facilities that require Conductive Flooring typically cannot use ESD flooring. The good news is that most Epoxy.com ESD flooring can be made to be conductive by first priming with Epoxy.com Product #671 Conductive Primer Sealer – www.epoxy.com/671.aspx.

Most Commonly Used Conductive and Electrostatic Dissipative (ESD) flooring

Epoxy.com has a wide variety of conductive and ESD flooring systems. Product #671 –www.epoxy.com/671.aspx – for example can be applied with one coat as a primer and one coat as a top-coating creating a highly conductive flooring system at a very low cost.

Product #1ESD – www.epoxy.com/1esd.aspx – is available in 15 colors. It is 100% solids making it an ultra high solids bis-A epoxy floor coating designed to provide electrostatic control properties to various surfaces including concrete or other nonconductive substrates. The use of a conductive primer will transmit conductive readings through ESD (Electrostatic Dissipative) Epoxy Coating for ESD Flooring Epoxy.com Product #1 if applied no thicker than 15 mils.

Product #630 Conductive – www.epoxy.com/630conductive.aspx is a 100% solids epoxy Novolac chemical resistant conductive epoxy floor coating ideal for severe chemical and solvent storage requiring conductive and spark proof surfaces. Applied at a nominal 1/16”, Epoxy.com Product #630 Conductive Novolac Epoxy Chemical Resistant Conductive Floor Coating offers the superior chemical resistance of an Epoxy.com Novolac Epoxy Resin System while maintaining a conductive surface. It also is available in 15 colors

Epoxy.com Product #674 – Electrostatic Dissipative Urethane (ESD) Coating is a two component, Electrostatic Dissipative chemical resistant, polyurethane coating. The high gloss finish offers excellent abrasion resistance, chemical and stain resistance, and superior color retention. Epoxy.com Product #674 – Electrostatic Dissipative Urethane Coating can be used equally well on vertical or horizontal surfaces. It is ideal for concrete floors and walls in warehouses, storage facilities, aircraft hangars, animal housing, and vehicle maintenance facilities. Available in both clear and pigmented formulations, Epoxy.com Product #674 – Electrostatic Dissipative Urethane Coating can be used as a finish coating option for most Epoxy.com Flooring Systems.

Epoxy.com Product #675 Electrostatic Dissipating (ESD) Water Borne Epoxy Topcoat is a pigmented, water emulsion epoxy electro-static dissipative finish designed to have maximum penetration into concrete surfaces to provide high bond strength and adhesion. It has very low odor and can be used in occupied areas as a finish sealer in Thin-Film Electro-Static Dissipative Coating Systems.

Epoxy.com Product #676 Novolac Epoxy Chemical Resistant Conductive Floor Coating is a 100% solids – Zero (0) VOC epoxy Novolac Chemical resistant conductive (anti-sparking) epoxy flooring and floor coating system ideal for severe chemical and solvent storage requiring a chemically resistant conductive and spark resistant surface.

For help in selecting the right conductive flooring system for your application please call technical support at 352-533-2167 or email me at norm@epoxy.com.


Tombstone Repairs with Epoxy

August 22, 2012

A technician who uses a non-Epoxy.com product to repair tombstones wrote me recently looking for help with problems that he was having.  He goes on to say that the epoxy that he uses never fails, but rather the stone fails. When a secondary break occurs, the stone always re-breaks about 2 mm (about ¾ inch) above or below the epoxy joint.  The epoxy attached to about 2 mm of the stone and holds well.

He asked me if the epoxy shrinks so much that it will ‘ pull away ‘ from the stone it’s attached to, and in his case, it pulls about 2mm of stone with it.

No I doubt it is epoxy shrinkage causing the problem. High quality epoxy has little or no shrinkage.  It would have to be a very poor quality epoxy to be shrinking enough to do that.

The reason his epoxy is not working is that it is too rigid.  His existing rigid material has a “high modulus of elasticity”.  A material with “high modulus of elasticity” is a material that is stiff and/or rigid.  A “low modulus of elasticity” material is semi-flexible, and is not rigid or brittle.

Smaller pieces of the stone structure (in this case a tombstone) and pieces not in touch with the ground tend to get hotter and cooler faster than the larger pieces and pieces with ground contact. This is called “differential timing of the event”. For example the top of a tombstone can be heated and cooled on 5 sides, the top and the 4 sides. The base of the tombstone which is buried in the ground has earth or stone on all of its surfaces.  This earth and stone tends to keep the temperature of the base more stable by insulating it and slowing the change in temperature. This works much like the insulation in your house slows temperature changes inside your house.

When an object like a piece of stone is heated it expands (gets bigger).  When an object cools it contracts (gets smaller).  For example 100 feet of concrete will be 1 inch longer once it is heated 100 degrees F.  That is why expansion joints are cut into concrete.

In the case of tombstones all the pieces of the same type of stone have very similar if not identical “coefficient of expansion”. Since the pieces are positioned with potentially different timing of heating and cooling there is a “differential timing of the event” (see above). The result is stress areas you are seeing in the closest weakened plane in the stone near the bond line.

Product #2005  was specifically designed for tombstone (monuments) and/or stone bonding, or repair. Epoxy.com Product #2005 is very strong yet it is has a “low modulus of elasticity” (semi-flexible).  The low-modulus of elasticity helps to absorb differential movement (two sections of stone heating and cooling at different times), making it much less likely to cause a stress area in adjacent weakened planes.

Camouflage the bond line rubbing stone dust(ground off the original stone or a similar colored stone) into any exposed epoxy material while the epoxy is still “wet”. That way the dust will stick in the wet epoxy making the epoxy difficult to impossible to see.

Please send your additional question and blog ideas to norm@epoxy.com

 


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