1K or 2K Enamel Over Rustoleum Auto Primer

[Bingster]

I sprayed window moldings with Spray Max primer/filler, and a few metal spots came through in the sanding, so I'm spot painting them with the Rustoleum Automotive Gray primer.  I'd use another can of Spray Max primer but they're a little pricey for touch-up because once you activate that button on the bottom of the can the shelf life is nil. I'm not sure of the strength of the Spray Max 1K and 2K enamels in the FillClean cans, so I'm wondering if I need extra drying time for the Rustoelum or is that not the right product? I was told just to spray over the raw metal spots with the Spray Max enamel, but I'm not certain I want to do that.

Edited January 7, 2019 by Bingster

[Plymouthy Adams]

what did the label on the can have to say about its application, dry time and top coat application...

[Dennis Detweiler]

As an old and former auto body and paint repairman, it's usually advisable to use the same brand of paint and primer for proper adhesion. I'm not sure about the modern day Rustoleum products, but years ago they contained fish oil which is also a rust inhibitor, but also required a similar base for a top coat. Possibly fisheye eliminator added to the finish coat would suffice?  Maybe the ingredients has changed over the decades and it won't make any difference. An up-to-date auto body repairman should know. A sealer over the primer before top coat may also be advisable. .

[casper50]

I'd use a sealer first as Dennis suggested.

[Adam H P15 D30]

I am not an authority on paint and I would never claim to be, but I shot a 2 part Urethane clear coat over Rustoleum enamel on the roof of my 49 without issue.  In fact I shot it over the old paint and rattle can primer spots without issue.  7 months of sitting in the sun, rain and dirt, looks like the day I shot it.  FWIW

When finished spring of 2018

last month, no issues

Adam

[Plymouthy Adams]

I have  only had to use a mid sealer on one vehicle....nothing would lay on it without lifting and the owner just refused to take it to bare metal....I explained the outcome would be on him...fortunately...the mid sealer did the trick...I never knew the type paint I had to seal but always suspected a very cheap lacquer on a very cheap primer....

 

test the paints in a spot that would be easy to address in case of incompatibility.   

[Bingster]

The only hint that the Rustoleum primer said on the can that raised a red flag was if you're using lacquer over it, do a test piece

[kencombs]

14 hours ago, Bingster said:

I sprayed window moldings with Spray Max primer/filler, and a few metal spots came through in the sanding, so I'm spot painting them with the Rustoleum Automotive Gray primer.  I'd use another can of Spray Max primer but they're a little pricey for touch-up because once you activate that button on the bottom of the can the shelf life is nil. I'm not sure of the strength of the Spray Max 1K and 2K enamels in the FillClean cans, so I'm wondering if I need extra drying time for the Rustoelum or is that not the right product? I was told just to spray over the raw metal spots with the Spray Max enamel, but I'm not certain I want to do that.

I think I'd choose the red option above, if the bare spots are small.  Mixing materials is iffy at best.  The Rustoleum would maybe work, but if using that option, a longer cure time may limit the chances of lifting.  I think the Rustoleum primer is the old tech lacquer based stuff and will sometimes swell from the top coat solvents. Then, when the solvents evaporate, it shrinks, showing the sanding scratches beneath.

[Bingster]

Thanks. The fella that said painting over the smaller bare spots would be okay is Evan at the wood graining place. He matched some 1k Spray Max enamel for me, and I had used Spray Max 2K primer. It's had about a year to dry! Since the moldings are interior, I guess it would work out okay.

[MarkAubuchon]

I agree with and have first hand knowledge.  You are always better off using compatible products when painting. When I painted my cars I was given this advice from a body/paint guy.  I went so far as being consistent with filler, hardener, solvents, primer sealer and paint.   

[55 Fargo]

If the Rusto oil based alkyd enamel primer is fully cured, and I do mean FULLY CURED like weeks months later.

I have used 2 k urethane primers and paints over absolutely no issues.

I have used Limco Acrylic enamel over Rusto primer on my sons car 2 weeks later with no issues whatsoever.

I have used epoxy primers, all types of fillers and even some lacquer based primers over it too.

DO SO AT YOUR OWN RISK.

As in anything chemical there are no 100 percent gaurantees...good luck