painting knots on pine board

[Cooler]

I know better but I forgot.

I usually shellac the knots to prevent bleeding through the finish.  I forgot.  I used a good primer/finish ( Behr Marquis).

But now the knots are bleeding through.

Can I just brush shellac over the bleed areas and topcoat it with another coat of paint?  Or do I have to strip off the brand new "old finish" and start over?

[jteneyck]

I know better but I forgot.

I usually shellac the knots to prevent bleeding through the finish.  I forgot.  I used a good primer/finish ( Behr Marquis).

But now the knots are bleeding through.

Can I just brush shellac over the bleed areas and topcoat it with another coat of paint?  Or do I have to strip off the brand new "old finish" and start over?

No direct experience Cooler but my gut says you should scrape/sand off the paint where the blead through is.  And I would use BIN shellac primer instead of plain shellac.  

John

[Cooler]

No direct experience Cooler but my gut says you should scrape/sand off the paint where the blead through is.  And I would use BIN shellac primer instead of plain shellac.  

John

I think you are right.  I was hoping someone would tell me otherwise.  

If I seal where the knot is over the paint, I suspect it will continue to bleed horizontally.  Unfortunately shellac is not an outdoors finish and can only be used to spot prime the knots.

And Sealcoat works fine for this.  Indoors the BIN would make a fine overall primer eliminating one coat of color.  But for outdoors, I have the Sealcoat and it works fine (as long as you remember to actually use it).

[jteneyck]

I think you are right.  I was hoping someone would tell me otherwise.  

If I seal where the knot is over the paint, I suspect it will continue to bleed horizontally.  Unfortunately shellac is not an outdoors finish and can only be used to spot prime the knots.

And Sealcoat works fine for this.  Indoors the BIN would make a fine overall primer eliminating one coat of color.  But for outdoors, I have the Sealcoat and it works fine (as long as you remember to actually use it).

Just so you know, BIN shellac primer is Sealcoat + pigment.  For painted finishes it's a great choice, whether indoors or out.  

John

[Bope]

I will be interested in how you this comes out. I made some window trim with pine and used BIN primer and the knots still bled through. I tried shellac and repainting and back they came. No horizontal bleeding just straight back up. They are in the bonus room so I don't have to look at it very often.

[Cooler]

I will be interested in how you this comes out. I made some window trim with pine and used BIN primer and the knots still bled through. I tried shellac and repainting and back they came. No horizontal bleeding just straight back up. They are in the bonus room so I don't have to look at it very often.

I wrapped the posts in the front of my house with pressure treated 1" x 8"  boards.  I spot "primed" the knots with Sealcoat and then painted with the same Behr Marquis I am using now.  No bleed through for 7 months.  

My mistake this time was forgetting to spot prime the knots.

I am surprised that you did not get similar results.  Are you sure you were using a Zinsser primer that was shellac based?  They make several different types of water based primers too.