Which self etch rattle can is better, Mar-Hyde or SEM?

[sibriggs]

If you haven't tried the self-etching primer from Rustoleum sold at home depot and lowes you should. I found it to be much better in a number of ways.

It goes on smoother, sticks better and lasts longer. I've been using it on aircraft restoration projects for years. Some of the Sem and NAPA primers cause certain cover coats to wrinkle this one doesn't.

It works great on both steel and aluminium, drys fast and applies nice.

And no I don't have stock in the company.

:-)

[longline]

but I have found some paints wrinkle when top coating SEM. I have not figured out what is causing this, but suspect application issues rather than a problem with the SEM itself.
Generally, SEM appears to be rugged and fast drying. I like it, and will continue using it for the interior as it is easy to touch up any areas that show wear.

[agirard7a]

I've used both Nappa and SEM. In my experience, Nappa self etch did
Not adhere as well, scratchs off easily
and is not as durable as SEM. Also, over steel, they both will
rust through. Epoxy is by far the best way to go over steel. Also use epoxy on high wear areas.

[SteveT]

What are you using to clean/prep the surface before applying the NAPA or SEM rattle can primers?

[BobTurner]

Originally Posted by SteveT

What are you using to clean/prep the surface before applying the NAPA or SEM rattle can primers?

My paint shop (SEM) recommended:
Scuff with red pad
De-grease/clean with water and Dawn dish soap
Water rinse
Vinegar etch
Water rinse (water should sheet)

This seemed to work pretty well. I tried skipping one or more steps on scrap; paint didn?t adhere as well.