How do I stop knots from bleeding through primer
#1
03-06-13, 08:13 AM
How do I stop knots from bleeding through primer
Hi There
I have primed the knots on my pine trim several times now and about 3-6 months later the knot bleeds through. It has been three years now and still no paint because I am waiting to see if they bleed through. Any suggestions?
thanks so much
I have primed the knots on my pine trim several times now and about 3-6 months later the knot bleeds through. It has been three years now and still no paint because I am waiting to see if they bleed through. Any suggestions?
thanks so much
#2
03-06-13, 08:21 AM
Super Moderator
Big question is...what primer are you using? If it's not shellac based it will probably bleed through. Oil based may also work, but most people just use the shellac based to be sure.
#4
03-06-13, 08:40 AM
Super Moderator
Ahhh...I didn't notice Canada. The Zinsser site for CA shows it (shellac) still available. You may have to visit a real paint store if you haven't already.
You are probably using the BIN 2?
You are probably using the BIN 2?
#5
03-06-13, 08:45 AM
Group Moderator
Zinsser BIN is shellac.
Also, if you have not painted, you may still be able to see the knots; primer does not necessarily hide them, it just keeps them from bleeding through the paint.
Also, if you have not painted, you may still be able to see the knots; primer does not necessarily hide them, it just keeps them from bleeding through the paint.
#6
03-06-13, 09:03 AM
I normally caulk any cracks in the knot and then give it a good coat of exterior oil base wood primer. That keeps the knot from bleeding thru latex paint 90% [maybe more] of the time. When oil primer isn't good enough - a pigmented shellac like Zinnser's BIN is needed.
Vic, I've never heard of BIN 2. You aren't confusing it with Kilz II are you?
Vic, I've never heard of BIN 2. You aren't confusing it with Kilz II are you?
#7
03-06-13, 09:08 AM
Super Moderator
Mark....That was from the Canada Zinsser site. Dunno if they even have it here.
Well...looks like they do....RustOleum.com
Well...looks like they do....RustOleum.com
#9
03-06-13, 09:37 AM
Depends on where you live 
apparently the closest place to me is Winston/Salem.
Had a hard time deciphering their website but apparently it's a waterborne version. I'd have to try it multiple times before I'd trust it. The Zinnser name/reputation would be the only reason I'd try it.
apparently the closest place to me is Winston/Salem.Had a hard time deciphering their website but apparently it's a waterborne version. I'd have to try it multiple times before I'd trust it. The Zinnser name/reputation would be the only reason I'd try it.
#11
03-06-13, 09:43 AM
Super Moderator
Bakkus, be prepared for the smell. It is much stronger than what you've been using. You will probably need to ventilate.
The Pros will be able to confirm or debunk this....but I think you may want to paint all the trim with the new primer not just knots. I THINK it can cause the shellac primed areas to stand out if you don't.
The Pros will be able to confirm or debunk this....but I think you may want to paint all the trim with the new primer not just knots. I THINK it can cause the shellac primed areas to stand out if you don't.
#12
03-06-13, 09:50 AM
The paint over the pigmented shellac will take longer to dry. When coverage is iffy, the areas primed with shellac won't cover as well as the rest. I rarely do more than spot prime with BIN. If those areas don't look right when dry [give it plenty of time] another coat of paint should fix it.
#13
03-06-13, 10:36 AM
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This is interesting. I wonder if Bin 2 is some new product or something? I've been buying BIN from all sorts of places for about 10 years now and have never seen anything called BIN 2. It is pretty much the stinkiest stuff in a painters arsenal, but I've never seen it fail at sealing anything. Except once, I 4 coated creosote stains with it and they continued to bleed through. Turned out the chimney had been repaired, but not perfectly and water was still getting in.
I'd second what others said. You may still see the knots, but they aren't bleeding through. BIN's a primer, and very few primers have great coverage. That's what the paint is for.
Just checked it out on the website, and yep it's a soya based alternative to regular BIN. Likely less stinky. Here in Canada, there's been a huge transformation over the past year. All paint stores and 'departments' liquidated all oil based paints (not primers), unless they were considered "specialty products". Some have begun bringing in soya based alternatives, which apparently is the direction they're heading in.
I tried the soya based paint thinner before the oil paints went away. WAY less effective than regular paint thinner.
I'd second what others said. You may still see the knots, but they aren't bleeding through. BIN's a primer, and very few primers have great coverage. That's what the paint is for.
Just checked it out on the website, and yep it's a soya based alternative to regular BIN. Likely less stinky. Here in Canada, there's been a huge transformation over the past year. All paint stores and 'departments' liquidated all oil based paints (not primers), unless they were considered "specialty products". Some have begun bringing in soya based alternatives, which apparently is the direction they're heading in.
I tried the soya based paint thinner before the oil paints went away. WAY less effective than regular paint thinner.
