Technical Can Rustoleum be painted over?

Was told that Rustoleum has fish oil in the mix which causes other paints to not stick to it. Is this an urban myth?

 

usually if it sands, paint will stick
what are you planning to put on it?
I wouldnt put costly paint over it

 

It can be painted.... With more rustoleum, or oil based/tractor paint yes

 

Fish oil only in the red oxide primer.

 

Don't put automotive paint over it, it will wrinkle and lift.

 

I believe the fish oil was dropped quite a few years ago. And the main problem was you couldn't use 'standard' reducers with it if spraying, you needed their 'special' reducer.

As far as spraying over it, as long as it's fully cured you can but it takes a very long time for Rustoleum to fully cure. I've seen brush-painted Rustoleum remain soft for 2 years plus... Basically, if it clogs your sandpaper when sanding it's still not fully cured.

 

You can paint over it with enamel.

 

I sandblasted and primed the firewall with rustoleum rusty metal primer on my 31 pickup back in 78. It sat in the sun and was well baked. I eventually primed and painted it with lacquer in 86 and it has never wrinkled or peeled and is just fine even now.


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Rustoleum does indeed still use a modified fish oil in the red oxide primer and it is thinned with regular mineral spirits/ paint thinner that you would thin alkyd enamels.

The fish oil is what aides in penetration and absorbing into rusty metal.

MSDS SHEETS has a ton of information on the subject. HRP

 

Don't just plan on spraying the new paint over the Rustoleum, you're going to sand it first, right? Then spray it with primer before spraying the new paint. No problem.

 

You're getting basically the right answers above. The main cautions are age and what will be put over it. Even well aged, some solvents in the newer auto grade materials are pretty aggressive for chemistry reasons and evaporative values required for purge/cure rates. Even a modern 2K type prmer has it's solvents or binders in the mix even if unreduced. Best advice? Try an outta the way spot, and put it on just a little heavy and wet. If it holds up go for it but be conservative anyways. If it's more Rustoleum over old rustoleum (a few years) you'll also likely be ok.

 

In '80 I had a '65 El Camino that got hit hard. My students found out how to change a frame. They brushed Rustoleum on the new (used) frame and I cut the left over with varsol and sprayed the bottom of the body.

 

Then it's been changed. I distinctly remember in the early '70s that they were very insistent that you use their 'special' thinner if spraying it and they noted that it was because of the fish oil. The thinner wasn't easy to get and rather expensive. You could use mineral spirits for clean up only. And they weren't kidding, I did try mineral spirits and it 'curdled' when sprayed.

 

Thanks for the responses. Rustoleum has a good choice of different colors so used some for touch up. Mentioned that when buying automotive paint at the local supply and they said other paints wouldn't work over the Rustoleum. Used the Rustoleum primer and color coat combination rattle can, seems to sand ok without clogging the paper.

 

Id suggest getting a cheap gun and real automotive primer. The rattle can primer is softer / shittier than real auto primer. Even when you block it out, the paper cuts faster on the rattle can primer and youll get waves that come thru in the final coat that you cant see until the topcoat is on.

You could use real auto primer over what you have as a sealer to lock it all down and block sand that, but why build over low quality base products. Id would personally sand it off.

This is all assuming when you shoot a real primer over the rustoleum. It doesnt wrinkle or lift.

If you want to use rustoleum or industrial enamel, I prefer valspar, on the whole job, thats fine. Ive used a lot of that before and its pretty tough low cost paint that gets the job done. I shoot valspar tractor enamel with acetone and valspar hardener. Takes longer to cure but it will cut and buff.

I still would use a better primer than rattle can to level and blend, block out the surface. The rattle can just doesnt have enough solids in it to fill, level, build well.

 

I've clear coated Rustoleum with automotive urethane clear a few times with no issues.

 

I was a service rep for Rustoleum for 30 plus years, I honestly don't recall ever hearing that you had to use Rustoleum brand thinner, spraying the red primer worked using conventional paint thinner but acetone worked much better. HRP

 

I thought it smelled funny.

 

Well, this was about 45 years ago. It really stuck in my mind because I had to special order the thinner and it was more expensive than the paint. FWIW, the finished paint was extremely tough; I became concerned with internal rust on the frame and had a local guy do a chemical dip (the EPA shut him down not too long after...) and he asked me 'what kind of paint is that?!' He told me he had to dip/pressure wash the frame four times to get all the Rustoleum off...

I do think they changed the formulation somewhere in there. My mother painted a steel lawn chair around 1960 that had serious surface rust all over it. Prep was she washed it.... Two brushed-on coats of black Rustoleum and that chair became a household fixture, finally just being thrown away, not because it had deteriorated, but because on a sunny day it got so hot you couldn't sit on it. That, and it weighed a ton... LOL.

 

I used the "Hammer Tone" once and regular thinner would not work. I think I used Lacquer thinner or Acetone and that worked...