February 4, 2004

In This Issue of The Acid Staining Newsletter

Take the Guesswork out of Temperature Readings
Getting answers to YOUR acid staining questions

Take the Guesswork out of Temperature Readings

My company has a problem finishing jobs during the winter months. We get the whole floor stained and cleaned and are ready to seal our work, but there is often a delay with heating installation in the new building. As you know, most clear sealers require that the temperature of the SLAB ITSELF be at least 40 degrees Fahrenheit. Our next coating, the acrylic wax, requires a temperature of 50 degrees, while some 2-part acrylic epoxies require at least 55.

We are often pressured by the builder to "just try the sealer, anyway." He may point out that he has placed 3 roaring propane heaters in the space for two days and the air temperature is up to 82 degrees. Unfortunately, when the slab is in contact with the frozen ground beneath it, warming up the air is not sufficient. Few builders want to keep propane heaters going all night, with no one on site to oversee them. In the New Mexican desert the temperature can quickly drop below freezing every night, although it may rise to a pleasant 55 degrees each day.

When we do try using our water-based acrylic sealer under such circumstances, it can be deceptive. These sealers go on milky and only later dry to clarity. They can appear to be adhering in a normal manner and do, indeed, dry clear at first. After a few hours of drying time, however, white streaks of powdery sealer can begin to show up all across the floor. This will happen especially near doorways when the door gaskets have not yet been installed, or in a side room which the builder has not heated.

Once, in a borderline situation, we thought we had gotten lucky. The sealer dried clear and looked fine from a distance BUT when we rubbed our hand over it, it came up as a fine powder on our hands. Since it is quite a chore to remove half-adhered sealer, we stick to a policy of "better safe than sorry."

Until recently, we have had to determine slab temperature by feel, if I put my hand flat on the slab and it felt similar to an ice cube I would tell the contractor that it could not be sealed. One contractor I worked for had a temperature-sensing heat gun. He could simply aim it at any part of the floor, pull the trigger, and get a temperature reading of that location in degrees. I was excited to discover that such a tool existed. (I had tried thermometers and temperature sensing strips and found they just measured ambient temperature.)

You can buy an expensive version of this laser at a specialty tool store and it will be guaranteed accurate within one or two degrees. But if you go to a restaurant supply store, you can get one for $20 to $30 and it will be accurate within three or four degrees. (The restaurant and FDA people use these to measure the temperature of meat in storage.) This is certainly accurate enough for our needs and will be much more convincing to a builder on a tight schedule than my old palm-on-the-floor technique.


I am constantly receiving emails and phone calls from people who have very specific questions they need answered. I enjoy helping people overcome these problems and create really beautiful floors. Plus, it gives me a better understanding of what information my readers are looking for.

Unfortunately, the magnitude of questions I have been receiving lately has made it impossible to respond personally to every one. That is why I was so excited when my publisher came to me with this idea...


I want to know YOUR biggest question about artistically stained concrete. Once I've received some feedback my crew and I are going to answer as many questions as we can.

What is in it for me? I will use the information to update my books with the current information my readers want to know about.

What is in it for you? You get access to all the questions AND my answers at no cost!

Click on the link below to participate...


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