# Sealing tannin bleed through



## ChelsO

Has anyone every tried a water based varnish as a base to painting wood white?I've done smaller areas with a shellac but the square footage of this place has me looking for a different approach. It's 4 inch rough faced pine needing to all go white. 
We use a lot of sansin products, namely the purity glacier. We clear coat mainly with this and I've never seen tannin bleed. 
Would it work to use this as a sealer as opposed to any oil based products? 
Thanks!


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## Holland

ChelsO said:


> Has anyone every tried a water based varnish as a base to painting wood white?I've done smaller areas with a shellac but the square footage of this place has me looking for a different approach. It's 4 inch rough faced pine needing to all go white.
> We use a lot of sansin products, namely the purity glacier. We clear coat mainly with this and I've never seen tannin bleed.
> Would it work to use this as a sealer as opposed to any oil based products?
> Thanks!


Your question is a little confusing, so pardon me if I don't give you the answer you are looking for. 

Water-based anything will not eliminate Tanin Bleedthtough, especially if you are painting wood white. Varnish should not be used under paint, as it is not an appropriate base for paint. Shellac is considered the "universal" sealer, as almost anything will adhere to it without problems (and it is great blocker for Tannins) - not so with varnish. 

Coverstain Primer (or similar) is as a decent primer that inhibits Tannin Bleedthough, and it can be topcoated in about 20min. .


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## ChelsO

I know shellac is the go to for this type of thing. I'm basically just trying to swing at something new with all the new, more environmentally friendly products that exist now. (This project just happens to be in the middle of a national park.)
I've done a few sample boards with the low luster water based varnish and painted over top. Covers good, sticks good but it's the longevity that I'm left worrying about.
It's all new wood, no previous stain or sealer.
I guess in my head, if I'm not going over oil base varnish or a polyurethane and if it seals, why not try it? Has anyone ever tried?


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## ChelsO

I realize I may sound out to lunch, and it's fine to tell me that, but I figure if can't hurt to throw it out there. I'm dreading spraying 3000+ sqft of shellac.


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## RH

ChelsO said:


> I realize I may sound out to lunch, and it's fine to tell me that, but I figure if can't hurt to throw it out there. I'm dreading spraying 3000+ sqft of shellac.



I’ve had to do it a few times - can easily understand your desire to find a less nasty alternative.


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## cocomonkeynuts

Was there any consensus on zinnser smart prime?


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## Holland

ChelsO said:


> I know shellac is the go to for this type of thing. I'm basically just trying to swing at something new with all the new, more environmentally friendly products that exist now. (This project just happens to be in the middle of a national park.)
> I've done a few sample boards with the low luster water based varnish and painted over top. Covers good, sticks good but it's the longevity that I'm left worrying about.
> It's all new wood, no previous stain or sealer.
> I guess in my head, if I'm not going over oil base varnish or a polyurethane and if it seals, why not try it? Has anyone ever tried?


Shellac is all-natural: better for the environment than most paint products. 

*It is recommended for interior and spot-painting exterior, but NOT large scale exterior tannin blocking.


"Shellac is an all-natural resin of insect origin that is harvested regularly and is therefore an environ-mentally friendly renewable resource. Non-toxic/hypoallergenic – The U.S. Food & Drug Administration has certified shellac as a protective glaze for candy and pharmaceuticals." Fine Wood Finishing


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## ChelsO

Don't really have the option to spot prime. By the time we hit all knots, it'll practically be full coverage anyways. Hence trying to find an alternative.


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## finishesbykevyn

Go figure they wouldn't preprime it all...
A regular water based primer like 123 would be better but still wouldn't stop knots from bleeding. But maybe that would be a cool look?


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## RH

Holland said:


> Shellac is all-natural: better for the environment than most paint products.
> 
> *It is recommended for interior and spot-painting exterior, but NOT large scale exterior tannin blocking.
> 
> 
> "Shellac is an all-natural resin of insect origin that is harvested regularly and is therefore an environ-mentally friendly renewable resource. Non-toxic/hypoallergenic – The U.S. Food & Drug Administration has certified shellac as a protective glaze for candy and pharmaceuticals." Fine Wood Finishing


Maybe the shellac itself is non-toxic but the binders and carriers which it is combined with in the primers must be. Of all the things I use, shellac based primers are the worst.


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## Holland

RH said:


> Maybe the shellac itself is non-toxic but the binders and carriers which it is combined with in the primers must be. Of all the things I use, shellac based primers are the worst.


Isn't the base for most Shellac Denatured Alcohol? Surely it can't be worse than the Petro. Distallates found in most oil base, or the solids found in most latex.


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## Holland

ChelsO said:


> Don't really have the option to spot prime. By the time we hit all knots, it'll practically be full coverage anyways. Hence trying to find an alternative.


I use Coverstsin for exterior priming to cover Tanninbleed and knots, or sometimes an oil based exterior stain (like P and L Stainshield).


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## RH

Holland said:


> Isn't the base for most Shellac Denatured Alcohol? Surely it can't be worse than the Petro. Distallates found in most oil base, or the solids found in most latex.


I’m no chemist, and don’t want to play one on PT, so you may be totally correct but there is something in it that certainly makes it seem really bad. I still work with oil based enamels on occasion and they don’t seem anywhere close to being as nasty as shellac based primers are. Spraying it is the worst.


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## Holland

RH said:


> I’m no chemist, and don’t want to play one on PT, so you may be totally correct but there is something in it that certainly makes it seem really bad. I still work with oil based enamels on occasion and they don’t seem anywhere close to being as nasty as shellac based primers are. Spraying it is the worst.


Yeah, I'm working with Shellac today, and my wife is complaining because I left the door open for like 2 minutes, and it got into the house (I'm taking Covid-19 time to catch up on some personal projects). 

Spraying it sounds horrific (and explosive)!


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## Redux

The only effective method I’ve used to prevent knots from bleeding is to bleed the pitch utilizing a blow torch, letting it solidify after oozing out, and then scraping it off, skipping shellac altogether and just priming. 

Tannin bleed shouldn’t be an issue with rough surfaced pine as per the thread title. Pine contains minimal tannins. Pitch can often bleed through finishes on pine other than at knots if the pitch wasn’t properly set when the lumber was kiln dried. Pitch is solvent soluble and can bleed through oil/solvent based coatings if present.


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## RH

Holland said:


> Yeah, I'm working with Shellac today, and my wife is complaining because I left the door open for like 2 minutes, and it got into the house (I'm taking Covid-19 time to catch up on some personal projects).
> 
> Spraying it sounds horrific (and explosive)!


Only time my trusty 3M respirator with chemical cartridges couldn’t keep up was when spraying that stuff. If I had to do much of it, I’d invest in a full face contained air system. 
These days, due to the process of retiring, I boot those jobs down the line.


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## ChelsO

Went with the shellac. Sometimes our job can suck but only 2 rooms left. Thanks for all the feedback. Lots of breaks and open windows.


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## 54pontiac

finishesbykevyn said:


> Go figure they wouldn't preprime it all...
> A regular water based primer like 123 would be better but still wouldn't stop knots from bleeding. But maybe that would be a cool look?


I call that look Bad Prep.


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## mmpaint

I just saw this post. I used to think that oil primer would block tannin, but I used it at my own house and saw that it did not, even after multiple coats. I called Zinsser and they said no, oil primer doesn't always block tannin. They said they only have one waterbased product that blocks tannin, which is BIN Advanced. I know a lot of people on here have had bad results with BIN Advanced, but I tried it and have had good results. I have done some tests on boards and have not seen any bleed through. Maybe they have improved it?


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## The_Finklestein_Kid

Hey there. I do a lot of wood finishing and refinishing and like M.L. Campbell’s aqualente plus High solids waterborne primer/sealer and line of clears when I’m trying to avoid odors of shellac/ lacquer. Depending on the wood I’ll sometimes use varathane sanding sealer because it’s a waterborne sealer but I prefer shellac based for obvious reasons. The aqualente primer dries super fast and is extremely sandable. Used in combination with bj advanced or Pratt and lambert waterborne alkyds and varathane diamond floor finish or the aqualente plus clear coats have given me some excellent results on cabinets/furniture/ trim work. If I’m in a situation where spraying isn’t ideal, I thin my finishing coats with a blend of extender/water and increase the ratio as I build coats. I jam a whizzy roller with the finger of one of those thicker black disposable gloves when applying my clear coats (for wider surfaces) to avoid lap lines/ streaks. Obviously if time isn’t on my side I tweak as needed. That’s been less of a problem lately.


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