Jim Hammill, co-founder of the Professional Detailer Technicians Association (PDTA), answers a question submitted by an anonymous detail shop operator asking how to remove cement from a vehicle’s exterior.
Question: What’s the best way to remove cement from a vehicle’s outer surface?
Jim Hammill: Concrete splatter on the painted surface of a vehicle can be one of the most perplexing issues to deal with for a detailer or a carwash operator.
Although it is not impossible to remove, it is a lengthy process that cannot be hurried. There is no quick way to remove this product safely from the vehicle’s finish.
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The trouble with concrete
Concrete consists of several ingredients that on their own are very damaging to a paint finish: gravel or crushed stone, cement and sand.
Once these ingredients are mixed with air and water they go through a chemical process known as “hydration.” The ingredients go from a liquid mass to a hardened mass.
This is why the procedure to remove concrete must be a chemical one and not a mechanical one. Any attempt to remove the concrete mechanically will result in permanent damage to the paint film.
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The only way to safely remove the concrete then is to change the state of the concrete. Thankfully, there are now several products made by chemical suppliers that can do this and remove splatter without harming the operator or the paint film.
These products reverse the process and turn the concrete back into a liquid, where it can safely be washed from the paint film. Check with your local chemical supplier or search online to find one of these products.