Evaluation of a Portable Laser Depainting System
SOUTHWEST RESEARCH INST SAN ANTONIO TX
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SUMMARY The laser was found to be efficient in removing CARC with coating removal rates comparable to those of sandblasting. Charring was observed in some cases during laser decoating, probably due to low laser fluence. Paint residue was found on the charred surface indicating incomplete paint removal. Preliminary studies of selective coating removal showed that the laser can be optimized to remove the topcoat without damaging the primer layer. The laser treatment did not affect the surface roughness of the test panels, while sandblasting markedly increased the surface roughness and caused significant damage to the oxide layer. The impingement of high velocity sand particles also led to Si contamination of the surface. Thermal load of the substrate during lasing was measured using thermocouples attached to the back surface of the test panels. The temperature of the carbon steel substrate increased with each pass of the laser beam across the surface. The maximum temperature value found during laser treatment of CARC-coated test panels did not exceed 302-deg F, which was determined to be the upper limit for the thermal stability of CARC.
- Lasers and Masers
- Coatings, Colorants and Finishes
- Solvents, Cleaners and Abrasives