Hi there, hoping someone could explain this sentence that is on my 2k High build tech sheet.


"Large areas of bare steel and areas where polyester body filler will be applied should be coated
first with AP-4110 Protec Epoxy Primer (faster option) or PP-3450 Paraglaze CT 2K HP Epoxy
Primer - Grey or AP-4441 Protec Etch Primer"

I understand it's telling me to use epoxy over the bare steel before applying body filler or this primer, but what about applying this primer over the top of filler?

Is it telling me that if I have to rework a low spot during blocking of the primer with some finishing glaze, I have to spot prime that spot before putting more 2k primer over the top?
This seems incredibly laborious!

Any help will be appreciated. Thanks

Basically they are saying to spray bare metal on your car with epoxy primer prior to applying filler or spraying 2k primer.

If you shoot the entire car with a quality epoxy primer it will provide rust protection and a great foundation for your paint job. Generally body filler can be applied without sanding the epoxy first IF still in the re-coat window. Once done with filler work, you can spot prime those areas if you choose or go straight to your 2k high build or polyester primer.

Thanks for that, that's exactly as I have been doing, it's just I needed to use some filler over the 2k to fix a low spot and I want to spray another couple of coats of 2k but didn't know if I had to epoxy the spots first. The tech sheet wasn't really clear!

I understand, it's because usually 2k high fills and surfacers are porous. It wants epoxy down first so moisture from the 2k won't go down the layers into the bare steel and cause issues from underneath.

I've painted the whole car already except the bonnet, which i'm doing now (first bonnet was binned and had to source another one).

With this particular car I have done the following:

1. Strip to bear metal
2. Initial metal repairs (pulling dents, rust work etc)
3. Epoxy
4. Block epoxy and apply filler
5. Epoxy
6. 2k high fill (either wet on wet or after blocking the epoxy)
7. Blocking (if any more work needs to be done that 2k primer wont fill, use some very fine filler)
8. Epoxy over filler repairs
9. More 2k
10. Final blocking
11. Paint

Surely step 8. isn't needed? The early filler repairs and bare metal have all been covered in epoxy.

Thanks