Code of Federal Regulations Title 49. Transportation § 49.587.16 Adhesive bonding procedure

Immediately before bonding, aluminum sheet surfaces to be bonded are thoroughly cleaned using a suitable solvent, such as 1–1–1 Trichloroethane. This is carried out at least twice and more often if required to eliminate grease or dirt deposits. The cleaned surfaces are abraded using 120 grit abrasive paper. Metallic/silicon carbide abrasive paper is not to be used. The surfaces are thoroughly abraded and the abrasive paper changed regularly during the process to avoid clogging, which could lead to a polishing effect. Following abrading, the surfaces are thoroughly cleaned again, as above. In total, the surfaces are solvent-cleaned at least four times. All dust and deposits left as a result of the abrading process are removed, as these can adversely affect bonding. The adhesive is applied to one surface only, using a ribbed rubber roller. In cases where honeycomb is to be bonded to aluminum sheet, the adhesive is applied to the aluminum sheet only. A maximum pressure of 0.5 kg/m² (11.9 lb/ft²) is applied evenly over the surface, giving a maximum film thickness of 0.5 mm (0.02 in).