Originally Posted by wayne gillis
I agree with stripping it down to bare metal with 80 grit , than applying some
etching primer to protect against rust .
Etch Primer will work and is an excellent product, however, with the epoxy technology being what it is today it is basically a glue (epoxy) with rust inhibitors in it, they have much more build than an etch and some, depending on brand, have respectable sanding qualities. This allows the individual to either go from metal, to Primer to top coat (wet on wet), or from metal to primer to block sand to top coat. It's all a personal preference, both work well.
Yesterday, I stripped a frame, 2 coats epoxy, flash, 2 coats satin black poly urethane. Worked very well. Etch primer, without the build properties, would require another top coat to fill the profile of the metal after stripping, where as the epoxy did fill the profile, gave the rust protection and allowed me the wet on wet process in order to complete the task in one day.
The frame I did is not for a vehicle that is going to be exclusively shown at car shows, it's a show driver, rain or shine. On the other hand, if it was a show car only (Trailer Queen), when basically time and budget constraints where not an issue, I would prefer the method of either the etch or epoxy, 2K high build, block sand and top coat, not only for the frame but, the entire car.
Hope I explained it well enough.