Floor Talk
 

Welcome to Floor Talk.

My name is Doug Wendler, and I have been invited by Applied Industrial Flooring Canada to provide this bi-monthly contribution to the website, sharing with you some of my flooring experiences and knowledge collected over the last forty five years. I will be writing about floor issues that may allow you to avoid some major pitfalls, get a bigger bang for your flooring dollar,  make your floor installation less stressful or just put a smile on your face by recalling similar experiences.  Please e-mail me at floor_techsupport@hotmail.com   if you have floor questions, floor problems, comments about this column or topics you would like to see.  

Seeking advice, here, on problems in the area of personal relationships or financial management is not recommended.  J

August, 2006

COATING: 

Thickness:   The Theoretical Reality. 

Coating thickness is usually presented (specified or quoted) in mil or microns.  With this advent came a constant confusion of the mil with the mm (millimeter).  The mil is one thousandth of an inch and is predominantly used in tooling and machining where tolerances are very small. 

I personally think that the introduction of the metric system is simply an ego trip.  Have you ever looked at an architectural drawing?  Hundred thousand square-foot facilities are laid out in millimeters. Look on your ruler to see the size of a millimeter.  It’s approximately one twenty fifth of an inch.  Now a four hundred square-foot studio-condo becomes a 36-million square-millimeter mansion, and your twenty five hundred square-foot home becomes a whopping two hundred and twenty five million square millimeter palace.  If I were the architect or general contractor I would be able to justify my bill more readily if it was expressed in trillion square millimeters rather than in thousand square feet. 

Whole numbers are easier to work with, so we deal in mils, or, if our ego is a little bigger, in microns when defining coating thicknesses.  

Now that we have established the descriptive measuring units for the thickness of the coating we want, what are we really getting?  Let’s assume you are quoted on a coating with a final thickness of 15 mil.  Sounds simple.  What does this mean in reality?  If the floor is prepared with mechanical shot-blasting (see shot blast in the Floor Glossary of this web site), then a profiled surface is generated, similar to a sheet of medium sandpaper.  This is excellent for bonding, but the surface area has just been increased 2 to 3 fold, depending on the depth of the profiling.

This can be compared to a linear example of the 8-inch saw blade with a 1/16 in. tooth pattern, that has a real surface length of 13 5/8 in..  Now if you can visualize applying a liquid over the top of the blade it is easy to see that the liquid will flow into the low parts and barely coat the tips.  The theoretical thickness you specified is 15 mil.  What is the real thickness? 

I have been in situations where the customer wanted a smooth uniform looking floor, and I quoted 15 mil.  The concrete was soft, and the shotblasting provided a rough profile.  In good faith we applied 20 mil, and the coating finish was still rough.  The customer was sympathetic, but not happy.  We did not get paid until we ground the floor smooth and applied another 10 mil coating.  We ended up coating the customer’s whole facility of 200,000 sq.ft. to his expectation. 

The reality is that thickness expressed in mil, or microns may not be the specifying factor to get you the coating surface that you want.  

Here are defining specification factors of a coating that I found useful in arriving at a desired end-result:

□        Finish
§         Smooth
§         Textured
          ·         Orange peel
          ·         Sand-filled ant-slip

□        Blemish free
§         No pinholes
§         No separation (“fish-eyes”)
§         No Roller lap marks
§         No lumps or foreign objects in the coating

□        Uniformity
§         Colour
§         Finish
§         Sheen
§         Thickness

□        Thickness
§         Minimum thickness
§         Coverage (sq.ft./gal. or sq. meters / liter)

□        Sheen
§         High gloss
§         Satin
§         Flat

□        Colour
§         Dark vs. light
§         vs. light Deep
§         Choice

□        Solids content

Be clear about what you want in these areas and you will avoid unnecessary hassle.
My September discussion will be on “Getting the Coating You Want.” 

Doug Wendler

 (The opinions and statements made in the above article may not necessarily be those of APPLIED INDUSTRIAL FLOORING CANADA.)