TxDOT Specification Item requires the application of an acrylic or water-based paint primer prior to the application of most thermoplastic materials on concrete surfaces and oxidized asphalt surfaces where no marking exists. However, most transportation agencies favor the use of an epoxy primer in these situations. Primer is used on concrete surfaces because it penetrates into the concrete surface better than thermoplastic; thus the adhesion strength should be stronger. It does not act as a moisture barrier or eliminate the need for a dry surface at the time of pavement marking application. Primer-sealers are not required for restripe situations, as the existing marking will serve as the sealer. Note that restripe marking materials must be compatible with the existing marking material. Refer to or manufacturer recommendations for material compatibility.

Refer to TxDOT Specification Item 666 and manufacturer recommendations for specific information on the use of primer-sealers. Refer to Section 4 of this chapter or to manufacturer information for a detailed description of recommended application procedures for various pavement marking materials. If an uncommon or experimental pavement marking material is to be used, refer to specific manufacturer instructions for surface preparation and application of this material.