In response to many customer inquiries requesting a quick drying and easy-to-apply coating which enables a restorer to quickly topcoat POR-15^® and other basecoats, POR developed POR-15^® Self-Etching Primer. With this product, you can even topcoat POR-15^® that's been in place for months or years. POR-15^® Self-Etching Primer is NOT a high-build primer, like POR-15's TIECOAT PRIMER, but it can be sprayed or brushed on almost any painted surface and can be topcoated in 15 - 30 minutes. It bonds incredibly well to POR-15^® Rust Preventive Paint, and all topcoats bond incredibly well to POR-15^® Self-Etching Primer. It can be sanded lightly, and, if desired, multiple coats may be applied. We strongly recommend this fine product. In situations where you are topcoating a very old POR-15^® finish, we first recommend a light sanding with any 280 to 320 grit paper.