Bed Wood Tech Tip info from a Mar-K Tech Tip that seems to has disappeared with Mar-K:

Apply on unfinished bed wood:

Three coats of POR-15 Rust Preventative Paint as a seal coat and three coats
of Behr gloss black enamel.

The finish has dulled slightly, but is still very glossy and has sealed well.

The finish has lasted much better than the first test series (that post/report has also disappeared?) in which
they used Behr primer and top-coated with the same Behr gloss black enamel.

Even though POR-15 Rust Preventative Paint is not specified for wood by the
manufacturer, it appears to be an effective primer if it is coated with a quality
topcoat paint.

If you plan to paint your bedwood, this finish system should be
considered as it is very durable and easy to apply.