TY - JOUR T1 - Adhesive Strength of Primers for Automotive Repair Painting under Various Roughness Conditions AU - Lee, Ju-Ho AU - Kim, Ho-Kyung AU - Hwang, Sung-Wan JO - Journal of Engineering and Applied Sciences VL - 14 IS - 21 SP - 7795 EP - 7799 PY - 2019 DA - 2001/08/19 SN - 1816-949x DO - jeasci.2019.7795.7799 UR - https://makhillpublications.co/view-article.php?doi=jeasci.2019.7795.7799 KW - automotive KW -roughness KW -repair painting KW -oil-soluble primers KW -Adhesive strength KW -variation AB - The aim of this study is to evaluate the adhesive strength of an oil-soluble primer under various sanding conditions for automotive panel repair painting. The adhesive strengths of paint coatings with various surfacers on steel surfaces were evaluated with variation of their surface roughness levels using various grades of sand paper. After the sanding process to instill different degrees of roughness, the surface in each trial was painted onto a steel plate coupon using a lacquer surfacer, a primer mixed surfacer, a surfacer with a wash primer and a surfacer with an epoxy primer. For each sample, the adhesive strength of paint coating was evaluated with a miniaturized tensile testing machine after the complete age-hardening of the painting over a corresponding elapsed time of 150 days. It was found that a coupon with a rougher surface generally, exhibited higher adhesive strength. The adhesive strength of paint coating under the as-received steel coupon (without a sanding process) was much lower than that of the paint coatings which were sanded. The adhesive strengths of the surfacer with a wash primer and the lacquer surface were 0.64 and 0.49 MPa, respectively. The adhesive strength of the surfacer with a primer was found to be higher than that without a primer ER -