Prepainted metal requires different handling and processing than bare metal. With many common misconceptions about prepainted or coil-coated metal vs. post-painted metal, the National Coil Coating Association in Cleveland provides six facts to set the record straight.
Fact 1. Precoated metal can
be handled successfully without harming the painted surface. It can be shipped
on flatbed trucks, moved with forklifts and stored as coils for long periods,
yet it will retain a flawless surface. The coil-coating supplier can provide
proper packaging such as wraps, bands and tape to protect the coils. Padded
fork lifts also are used at service centers when moving coated coils.
Fact 2. Coil-coated metal is more
durable than post-painted. In the process, sheets are uniformly cleaned,
pretreated and painted as a flat surface, so the edge-to-edge and side-to-side
variability sometimes found on post-painted metal is virtually eliminated. In
addition, prepainted metal often has two coats (primer and top coat) with each
tightly bonded to the metal, compared to post-painted parts that may only have
one coat of paint. In many cases, a prepainted part has paint on the backside
also, but a post-painted part usually has a minimal amount of overspray.
Uniform pretreatment and paint on the backside of a part increases its
Fact 3. Prepainted metal with
cut-edge weathers better than post-painted surfaces. Some manufacturers are
concerned with exposed cut-edge on prepainted metal, but the NCCA says that
field research has shown that prepainted cut-edge metal holds up better over
time than post-painted surfaces.
Fact 4. Using prepainted metal can
reduce costs for manufacturers. Outsourcing metal treatment and coating
operations can alleviate or eliminate the costs associated with meeting
environmental and health regulations, and overhead costs.
Fact 5. Prepainted metal can be
formed without any loss in surface quality or appearance. With the coil-coating
process, the paint system can be designed to have greater flexibility than the
metal. After metal has been precleaned, preprimed, pretreated and prepainted,
it can be formed without degrading the painted surface.
- Fact 6. Precoated metal can be joined using adhesives, mechanical assemblies (with or without fasteners) or welding and retain a flawless surface.