Priming Over Knots

kenvest

Working a front porch for a good customer. he had the porch rebuilt a few years ago and the previous contractor used some really knotty white wood, the knots have bleed through and look bad as the porch is painted in white.

the customer wants to use a porter cable ackrylic latex paint which i understand is a good product, but that alone will not be enough to cover the knots and keep them that way will it??

i see kilz has a premium primer out thats advertised to cover knots and stuff but i read here that some of you folks don't like the kilz...

what should i use?

Thanks for your time!

Exroadog

I would use BIN white pigmented shellac. 2 coats. Or 1 coat but I would probably still prime over it.

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ProWallGuy

I second the BIN.

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Wallpaper Hanger St. Louis
Digital Murals Installation

slickshift

Me Three
Use the BIN!
I still have an old open can of Kilz and I won't use it
It has got to be a few years old now lol

I think Kilz used to be better, I remember using it a lot more many years ago
Prolly why I bought this can a few years ago...big though
I won't use it

AAPaint

That answers that question.....talk about service!

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AA Quality Painting & Pressure Washing LLC
Jacksonville Painters
Jacksonville, FL.

Bret

The problem you are having is called tannin bleed through. As you applied the paint, the natural tannins in the wood were rehydrated by the paint and absorbed into the coating. I experienced this on a major level when i restored a large structure made of new red oak wood and pine. I applied three coats of solid color white stain over the wood and the bleed through still continued.
Allthough any good primer sealer might do the job, I used Sherwin-Williams A-100 Oil Wood Primer and had immediate results. The oil based solvent will not draw the tannins out of the wood.

Bret

kenvest

thanks for the good replys!

so let me get this straight, latex being water based will reactivate the tannins in the wood whereas a oli based primer will not?

thanks!

ProWallGuy

I don't think the water in latex reactivates the tannins, it just doesn't lock them in like an alkyd or shellac will do. Maybe it does, but I'm no chemist.

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Wallpaper Hanger St. Louis
Digital Murals Installation

kenvest

I appreciate your time!