# zinsser smart prime



## yacob (Dec 16, 2007)

after rolling primer did a compound touch up so i sanded today and spot primed with the smart prime and let dry then i started rolling the walls and what horrible picture i tought i was using semi gloss finish for primer had to recoat 3 times to get a decent finish did this ever happened to you?


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## Marion (Mar 30, 2009)

I have found that Smart Prime doesn't cover well. But, since it's new, I haven't came to a conclusion as to whether it does the job or not.


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## Masterpiece (Feb 26, 2008)

Interesting....I've used it on a number of interior ceiling water stains, some minor and some fairly severe. Perhaps the glossy finish is a by product of the stain blocking composition but I've never had any major issues with coverage or stain blocking. On a few severe and dark stains, a second coat was needed in a few small spots.
Aside from needing two coats to cover with a flat paint that was darker than the Zinsser, no real problems here. 

It's my first choice right now when some individuals will be inside while I'm fixing the stain/ceiling damage and don't want the smell of a solvent based if at all possible. 

But as far as waterbased stain blocking tech has come, it's still not a cure all.


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## Contractor Jeff (Apr 8, 2011)

Stain blockers dry with a harder film which changes the surface reflectivity and produces shiners when spot priming under flat paints. If you don't want to have to prime the entire area to prevent this, use this for spot priming under flat paints. It may take multiple coats to cover tougher stains.


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## BrushJockey (Mar 15, 2009)

^ . Spot priming always works the best when the primer is very similar to the base paint around it.


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## hammerheart14 (May 29, 2010)

Can you get the GOOD version of Zinsser, which is called Coverstain? The oil based version? MUCH better than the water counter part!


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## BreatheEasyHP (Apr 24, 2011)

For being water-based, Smart Prime is extremely good for some stain blocking, but is only moderately good at covering for color change.

I've used it to effectively block severe bleeding from Western Red Cedar. I tested out some 6-8 other stain-blocking water-based primers and all of them showed severe bleeding within 15 minutes of application, even after multiple coats.

I also tested some out on some severe staining from cigarette smoke and it appeared to work, but I didn't try another other water-based (I stuck with shellac primer for the job).

I've used it for many other purposes here and there and no problems; however, I've never used it on interiors.


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## BreatheEasyHP (Apr 24, 2011)

Contractor Jeff said:


> Stain blockers dry with a harder film which changes the surface reflectivity and produces shiners when spot priming under flat paints.


That's interesting. Is that also why spot priming with oil can cause flashing?

What's the best way to cure flashing? Another coat, or is there an intermediate step?


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## Contractor Jeff (Apr 8, 2011)

BreatheEasyHP said:


> That's interesting. Is that also why spot priming with oil can cause flashing?
> 
> What's the best way to cure flashing? Another coat, or is there an intermediate step?


There's nothing that can be done about how light reflects off a surface. Spot priming with most all stain blocking paints irrevocably changes the light reflectivity properties of the spot primed areas. The flat topcoat will show a shiner, even if you use 5 flat top coats to cover the shiner. Something to consider if you're the wanna be pro's pro. lol, just kidding, no.

Zinnsers dead flat interior primer is the only one I know of that dries dead flat. It's not a heavy duty stain killer, I had to go over some water stains twice. There were no shiners afterwards when topcoated with dead flat paint. 

Anyways, that primer is not the do all end all of all primer sealers and stain killers for all surfaces. If anyone knows of another interior primer-sealer-stainkiller that dries dead flat...


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## H2O Paint Chemist (Jan 7, 2010)

Contractor Jeff said:


> There's nothing that can be done about how light reflects off a surface. Spot priming with most all stain blocking paints irrevocably changes the light reflectivity properties of the spot primed areas. The flat topcoat will show a shiner, even if you use 5 flat top coats to cover the shiner. Something to consider if you're the wanna be pro's pro. lol, just kidding, no.
> 
> Zinnsers dead flat interior primer is the only one I know of that dries dead flat. It's not a heavy duty stain killer, I had to go over some water stains twice. There were no shiners afterwards when topcoated with dead flat paint.
> 
> Anyways, that primer is not the do all end all of all primer sealers and stain killers for all surfaces. If anyone knows of another interior primer-sealer-stainkiller that dries dead flat...


That would be my new Primezall.


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## Bighead (Nov 28, 2008)

Zinsser odorless oil stain blocker dries fairly flat. We use it to spot prime water stains on smooth ceilings.


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## acmasterpainter (May 15, 2011)

I thought Zinsser like you to spot prime then primer coat the whole surface before top coats to avoid flashing?


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## Contractor Jeff (Apr 8, 2011)

acmasterpainter said:


> I thought Zinsser like you to spot prime then primer coat the whole surface before top coats to avoid flashing?


No need to spot prime. If it's a smallish area, prime the whole area, see if the stain is gone. If it's a large area that will show up shiners after spot priming (at certain angles when the light hits it), decide if it's going to be noticable to you, because it will be to the customer. 


That's why I mentioned Zinssers primer (see post here) that dries dead flat. It's not as good a stain blocker as Bulls-Eye 123 or BIN, but I'd rather hit those stain areas a few times with dead flat primer and see if I can kill the stain, because I'll know the flat finish coat won't show a shiner. 

No stainkiller-primer on the market (that I've tried, maybe some do) dries to a dead flat finish as does Zinssers dead flat primer. It's worth using if the stain isn't too nasty, and you don't want shiners under flat paints.

BTW, Zinsser doesn't mention on the can in big bold letters that it's a stain killer, but the description on their site mentions it is. It's just not as effective a stain killer as their better ones.

Some painters and even customers, shiners don't matter. The stain was killed. But when working on expensive homes, I won't leave shiners, especially shiners on large ceilings. Walls don't show up shiners like ceilings do.


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## acmasterpainter (May 15, 2011)

Not sure I see the logic there. If you spot prime and and completely over paint a ceiling with the same primer, surely it will dry uniform? Whether it is flat or shiny primer doesnt really matter as it provides an even base for top coats?

Experience aside, just reading tech sheets, the chemists say you need at least 2 coats of water-borne stain blocker for the chance of a lasting result you can stand by. At least that is pretty standard fare on even the best "one coat wonder" stain blockers we have access to in Europe. (Mythic primer, Classidur and Zinsser)

cheers


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## Contractor Jeff (Apr 8, 2011)

Zinnsers Latex Primer dries completely flat. I've had decent stain blocking results with it. It's your call, so to speak.


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## howe (Apr 19, 2010)

*Exterior Smart Prime?*

Has anyone used the Smart Prime on complete exterior re-paint? 

I have always used oil on old crusty re-paints and on new cedar and just did a test to see how it would do on both cedar and aged pressure treated and on both it seemed to miraculously block tannins with one coat! I applied two finish coats of acrylic white and no bleed! 

I am considering using it on as full exterior which is a combo of previously painted and new cedar shake with lots of checking/blistering on trim, soffits and windows. Am I out of my mind?


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## Damon T (Nov 22, 2008)

Might want to look at the Zinsser peel stop triple thick for the checking alligatoring areas.


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## Contractor Jeff (Apr 8, 2011)

BreatheEasyHP said:


> That's interesting. Is that also why spot priming with oil can cause flashing?


Exactly. Other oil or latex primer/stain killers leave a hard film which causes flashing.

To answer the second question, about the only thing you can do is to cover the entire area with your primer/stain killer.

I'm just saying that if the stain is not too strong, or you just need to prime a portion of a ceiling and not see a shiner...Zinnsers dead flat primer does well. It's not a super stain killer tho.


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## I paint paint (May 4, 2014)

BreatheEasyHP said:


> That's interesting. Is that also why spot priming with oil can cause flashing?
> 
> What's the best way to cure flashing? Another coat, or is there an intermediate step?





Contractor Jeff said:


> Exactly. Other oil or latex primer/stain killers leave a hard film which causes flashing.
> 
> To answer the second question, about the only thing you can do is to cover the entire area with your primer/stain killer.
> 
> I'm just saying that if the stain is not too strong, or you just need to prime a portion of a ceiling and not see a shiner...Zinnsers dead flat primer does well. It's not a super stain killer tho.


You just replied to a quote made on 5-25-2011…


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