Water stains, nicotine stains, knots, children (markers, crayons, etc.), pets, they are all out there to make your house look a mess. You’re not powerless to fight them though. For painted surfaces there are some incredible stain blocking primers that can make these stains virtually disappear.
This is not going to be a consumer reports type post, but rather a Craftsman Blog reports type post. I’m sure there are a lot of other stain blocking primers that will work very well, but I’m going to give you my favorite primers that I have had the best results with in my career and what I use on a regular basis.
Why do you need a list of the top 10 stain blocking primers when one of these three will take care of just about any situation? Seriously, these primers have yet to let me down and I know they’ll do great for you too.
What is Stain Blocking Primer?
Some primers are meant for simple preparation of the surface in order to help the paint get a good hold and last for years. A stain blocking primer is designed to provide more robust coverage and prevent stains from bleeding through newly applied layers of paint.
Typically, these are oil-based primers or alcohol-based primers that come with the extreme stain blocking that you need. Latex paints have stain blocking abilities, but in my experience they only provide marginal coverage compared to their solvent based cousins.
Certain stains will appear to be covered upon first application, but then bleed through the paint months or even years after application. At that point you need to prime and paint all over again so using a stain blocking primer first is always a good idea when trying to paint over any of these items below.
- Water Stains
- Marker or Crayon
- Nicotine Stains
- Knot Holes
- Old-Growth Wood
- Certain Species of Wood (Redwood and Cedar)
- Pet Stains
- Wood Stain
- Covering Old Shellac
All of these items will need some level of stain blocking primer to get adequate coverage. I typically start with the easier to apply and less expensive stain blocking primers before moving up to the heavy duty ones only when necessary or when experience has taught me to start at the top.
A name intimately associated with stain blocking primers is Kilz since they have been in the game a long time. If you insist on using a latex stain blocking primer then this would be my choice. It is easier to use since you get the water clean up you want, and light to moderate stain blocking. This might work for crayons and light nicotine stains, but it is not particularly powerful for most stains in my experience. It’s a good place to start, but certainly not my go to primer.
This is an excellent oil-based primer for blocking stains both inside and outside. The oil-based formulation gives it a vastly improved stain blocking ability in my experience. I’ve used this on window restoration projects or to prime cedar siding and knot holes with great success and zero bleed through. You can use it to block most tannin bleed, graffiti, smoke, fire and water stains as well as sealing pet, smoke and food odors.
BIN Shellac Primer
For the worst stains and bleed through this primer has never failed me. It is a denatured alcohol based primer the uses pigmented shellac to hide stains. That’s fancy paint speak to say that nothing get through this primer. I’ve used this to defeat heavy tannins on old-growth woods or covering old finishes that can sometime bleed pink through other primers. It is only for interior and “spot” exterior use so you can’t fully coat exterior projects with this especially in hot climates which does limit it unfortunately. You also need denatured alcohol to clean your brushes, but its stain blocking power is unlike anything else I have seen.
How To Use Stain Blocking Primer
If you get into a situation that won’t cover with a traditional primer then before you paint, apply a coat of one of these primers. If after 24 hours you don’t see any bleed through then you should be good, but you need to give it some time to fully dry before assuming your coverage was successful.
Wood tannins in old-growth wood, knot holes and woods like cedar and redwood can take much longer to show through so you need to assume a stain blocking primer is needed. Skip it at your own risk and you’ll end up like the picture above of a cedar ceiling that wasn’t primed properly.
Sometimes you’ll see a pink color bleeding through your primer. You may wonder where the pink is coming from. This is wood tannins coming through and it almost always requires a shellac-based primer.
For exterior projects that need heavy stain blocking where you can’t use the BIN primer I would suggest using multiple coats of the Kilz Original to try to resolve the issue and only spot treating knot holes or trouble spots as they show up with the BIN primer.
Stain blocking can be a challenge and I hope this post has helped clear up some of the confusion on this topic. I hate seeing homeowners get analysis paralysis so I wanted to make it really simple by giving you three easy choices that are relatively easy to find in most stores.
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I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.