In response to many customer inquiries requesting a quick drying and easy-to-apply coating which enables a restorer to quickly topcoat POR-15 Rust Preventive Coating and other base coats, we have developed POR-15 Self Etch Primer. With the POR-15 Self Etch Primer spray can, you can even topcoat POR-15 Rust Preventive Coating that's been in place for months or years. POR-15 Self Etch Primer is NOT a high-build primer like POR-15 High Build Primer, but it can be sprayed on almost any painted surface and can be top coated in 20 - 30 minutes. It bonds incredibly well to POR-15 Rust Preventive Coating , and all topcoats bond incredibly well to POR-15 Self Etch Primer. It can be sanded lightly, and if desired, multiple coats may be applied. Use over a light coating over the POR-15 Rust Preventive Coating when it is dry to the touch but still tacky (has a finger drag) for top coating later finishing. In situations where you are topcoating a very old POR-15 Rust Preventive Coating, we first recommend a light sanding with any 280 to 320 grit paper, clean it, and use POR-15 Self Etch Primer. This self-etching primer spray paint for metal replaces Tie Coat Primer. POR-15 Self Etch Primer Technical Data Sheet