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Trying to paint varnished trim without the bleeding of that brown color.

Forum members suggested oil based stain blocker by zinsser. But they also have this shellac base stuff that is advertised as a stain blocker. Which one is better?
 

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Shellac based primer is shellac with white die and pigment in it. Shellac is one of the best stain blockers around, bar none.

Shellac is an alcohol based product. Not oil or water. So you will need to buy some denatured alcohol to clean up with. Paint thinner, mineral spirits or soap and water won't work.

Shellac is also great because it will accept any type of top coat with no issues.
 

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Radical Basement Dweller
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I use both depending on what I'm doing. Shellac is alcohol based and dries very quickly. If I'm refinishing furniture and want to make sure most any topcoat will keep its integrity, I use shellac to seal whatever it is I'm trying to cover.
If you use shellac, clean your brushes with either ammonia or alcohol (the denatured variety...not the medical stuff)

Ooops...was typing while Complete was posting. See above.
 

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^^ Great minds Robie :thumbsup: ^^

I should also add that shellac is very thin and can run if you're not careful. Also, if you re-coat it.... the second coat dissolves into the first, the third dissolves into the first two etc. It's all in how you want to "build" your finish. But, as a primer coat prior to paint.... a single coat is usually all you need.
 

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Shellac smells better, imo.
It sure DOES! :thumbup:

I LOVE using shellac whenever I'm staining something. It is a wonderful sanding sealer to use right after staining. It makes whatever you're staining just POP so your finish coats look even better than they would have normally. Plus, like Robie said, you can use absolutely anything as a top coat on the stuff.

It's also GREAT as a wash coat or conditioner for woods that tend to be splotchy when you stain them. Poplar, Maple, Birch, just to name a few. If you mix a 1# cut of shellac (I mix my own) or you can buy ready mixed shellac off the store shelf (usually, either a 2# or 3# cut) and thin it down (with denatured alcohol) to a 1# cut and give Poplar a wash coat before staining, it stains up just beautifully. So much better than any brand of "wood conditioner" I've ever tried.

As a primer, it's also perfect if there are brown spots on a ceiling where there has been a roof leak. Cover them with some shellac before re-painting and they're gone forever. Unless of course, you get a new leak.

:blink:
 

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Shellac is a resin secretes by the Lac bug on trees in India and surrounding area. It is collected and dries into flakes. It is mixed with alcohol and used as a finish that protects very well against bleed through and seals in odors. While we use pre-mix for most construction, it can also be bought in flakes. Most shellac is sold as dewaxed, which is what you want.
 

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Trying to paint varnished trim without the bleeding of that brown color.

Forum members suggested oil based stain blocker by zinsser. But they also have this shellac base stuff that is advertised as a stain blocker. Which one is better?
You posted pic of spray cans of BIN.
Spray can BIN has been thinned to get it to spray. It's runny and sags. Not nearly as effective on trim as gallon BIN.
 

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Have you noticed the price increase of Shellac over the past few years.... someone told me it had to do with the laq bug being displaced from its habitat by development in the third world countries.


Anyone know, how sensative really is shellac to shelf life......

I have an old can that says something like 2 year shelf life.... haven't tried it lately.

Best
 

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Renaissance Man
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Have you noticed the price increase of Shellac over the past few years.... someone told me it had to do with the laq bug being displaced from its habitat by development in the third world countries.


Anyone know, how sensative really is shellac to shelf life......

I have an old can that says something like 2 year shelf life.... haven't tried it lately.

Best
Your lucky if shellac lasts a year - gotta be fresh or it bogs down cure time and become a sticky mess.

No doubt, it's one of the best knots sealers out there, particularly sappy pine.
 

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Your lucky if shellac lasts a year - gotta be fresh or it bogs down cure time and become a sticky mess.

No doubt, it's one of the best knots sealers out there, particularly sappy pine.
EXACTLY right. :thumbsup: That's why I like to mix fresh whenever I'm going to use it. The flakes have gone up too. Not so much in the price per bag, but like stuff in the Supermarkets, they didn't raise the pricing all that much, they just reduce the size of the can, jar, box or whatever.

The net, net though, is a fairly healthy increase.
 

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Radical Basement Dweller
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I've purchased a few gallons in the last two months of amber as it is the exact match of existing cabinets....$45 per gallon...wtf?
 

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Pigmented shellac dries the hardest of any primer I've used. It's a primer stain killer and "turtle shell" all in one. I've used it to encapsulate peeling latex over oil, with decent results (decent compared to stripping off all the latex).
 
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