The 'E' Type Forum

I've been under the impression that epoxy primer is the modern way to cover bare metal while etch was for a quick "Duplicolor" quality repair (or temporary to prevent flash rusting) and red oxide went out along with lacquer.

But I noticed that CJ seems to use a lot of etch and epoxy but limits their use of red oxide to the diff. I Googled "site:classicjaguar.com "red oxide" to find this out.

Chuck at Monocoque is a heavy user of red oxide. Here he says "Two coats of red oxide, two coats of etch, one coat of epoxy primer, rubberized gravel guard, then finish paint." This surprised me as I understood that the acid in the etch helped it stick to bare metal.

Ignoring historical accuracy, are there generally accepted best practices for when to use red oxide, etch and epoxy?

Thanks,

Jim

I am not an expert in this area but I know etch primer is used on perfectly clean bare metal surfaces and is applied as a real thin coat. Its pretty much considered to be a sealer of bare metal and a base coat for primer. it is not painted on top of other paint. It is also not hydroscopic. A panel covered in etch primer will take months to show any rush pimples... where-as ordinary primer absorbs moisture from the air...

Red oxide is one of many choices with which to coat internal panels ti help deter rust from forming and there are mixed opinions as to its actual value as a preventative as it no longer contains lead like it used to. Technology has moved on and something like Por15 dries to an enamel like hard finish and I think is better inside box sections etc as it is seriously hard to remove.

epoxy is one type of primer-filler, i.e. a primer that you build up relatively thickly and sand down to get a good flat surface for the top coat.

So I would say....
1. Etch primer - 1st coat for all bare metal surfaces
2. red oxide (or any of the alternatives) only used to coat internal box sections
3. epoxy primer - a sandable primer-filler coat prior to colour

I would agree with Chris, can't see the point of putting etch primer on top of red oxide. The point of etch primer is it bites into bare steel.
When I worked in a pro paint plant all car/truck bodies were electro dipped, if they got damaged moving them around they would be rubbed down and sorted then given etch primer before the actual primer went on.

Dave

Actually, most epoxy primers don't fill and so typically aren't sanded. In order of "fill" modern primers go:

epoxy primer
2k primer
high fill 2k primer
polyester primer (for example slick sand)

Some epoxies (like SPIs) can be sanded. Some can't. Polyester primers are basically sprayable Bondo.

Jim

I stumbled on this primer primer.