Choosing the Right Chemical Stripper for the Job
What are you trying to remove?
Choosing the right chemical stripper for your particular project depends on a few key factors. Knowing what type of sealer or coating you are trying to remove is usually the most important. There are major differences between acrylics, polyurethanes and enamels. You typically want to match the strength of the stripper to the strength of the sealer. High-performance or thicker polyurethane and epoxy-based sealers are removed faster and more efficiently with a more aggressive solvent-based stripper. For thinner acrylic-type sealers, a biochemical or caustic stripper may be sufficient.
Knowing even a little about what you are trying to remove can go a long way in choosing the stripper that will be most the cost and time effective. If you have no idea what type of coating or sealer was used, here are some basic guidelines that can help:
Is the concrete inside or outside? Most interior sealers or coatings are acrylic.
How thick is the sealer or coating? Thicker sealers or coatings (as thick as dime or greater) are usually high-performance epoxies or polyurethane-based systems, while thinner sealers (thickness of paper) tend to be acrylics or enamels.
What is the condition and thickness of the sealer?
Once you have identified the type of sealer, or at least have categorized it as an acrylic or non-acrylic, you need to look at the condition and thickness of the sealer. Is the sealer in good shape and adhering well to the concrete, or is it loose, flaking, and coming off easily. You'll need to use an aggressive solvent-based stripper to remove sealer that is in good condition and well-adhered. For a sealer that is loose, weak or failing, you may be able to use a less-aggressive biochemical stripper.
Where is the work being done?
The other factor to consider is the location of the concrete to be stripped and the environmental impact of the type of stripper you use on surrounding plant life, structures and people. Safety should always come first when considering the type of stripper to use. (For more information about chemical stripper safety, read this document from the U.S. Consumer Product Safety Commission.)
Solvent-based strippers are the most aggressive and generate odor and possibly flammable fumes. Do not use these strippers in areas where sparks or open flames will be present. I also tend to stay away from using solvent-based strippers in public areas or places where the fumes can travel through HVAC systems and reach locations where people are working or living. The fumes given off by solvent strippers can be more dangerous than the actual stripper itself. In these situations, the new generation of eco-friendly biochemical strippers works very well.
Both caustic and solvent-based strippers will kill most plant life they come in contact with, as well as contaminate water in ponds and tanks where fish may be living.
As a side note, I have been involved with many successful projects where solvent-based strippers were used in public locations to remove stubborn high-performance sealers. It all comes down to managing the jobsite, providing adequate ventilation, and taking the proper safety measures.
Are you removing a specialty floor wax or finish?
There is another category of stripper specially formulated to remove floor waxes or finishes. These specialized strippers are often alcohol-based and are not as aggressive as other standard chemical strippers. Most are water-based and are designed to only remove the wax or maintenance topcoat finish without affecting the underlying sealer. Some manufacturers make strippers that will only target the specific chemical makeup of their floor wax or finish.
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