Paint Problems, Episode II: Attack of the Stains
Updated: Aug 29, 2019
Stains. They can happen anywhere. On clothing, linens, countertops and yes even in your brand-new paint job. But don’t worry they can be prevented or corrected; hope is not lost. At L.A. Design Centre, we know that no one likes an unsightly stain so I’ll just get right into it and stop wasting any more of your precious time.
Staining and Discoloration. What causes it?
There are many reasons that stains occur in a paint film. For our purposes today we are going to discuss discoloration due to wood tannins, mildew, water and smoke.
Wood Tannins. Let’s discuss…
Wood tannins are naturally occurring compounds that often seep to the surface and can give wood a beautiful, warm, golden undertone as they age. But they can wreak havoc on a paint job unless addressed properly. These stains often present themselves as tan, brownish, yellow or yellowish-brown areas that have come out of the wood beneath your paint and have worked their way to the surface. The most troublesome tannins are found in woods like cedar, redwood and mahogany. And areas, like knots, in other species can be quite bothersome as well. But all is not lost, there’s a pretty easy solution. Stain blocking primer!
Prevent the stains beforehand by applying a high-quality stain blocking primer directly to the wood surface or over an existing pant job to prevent it from coming through your new coating. Maybe you didn’t notice the discoloration until you got the first coat on. That’s okay. Throw on a coat of the stain blocker after the first coat is dry and before applying your second coat!
Oil based (alkyd) stain blockers are by far the best option to seal tannin stains. Though, in this situation, these products have optimal stain blocking capabilities they can be very smelly. Even the low odour versions. So, in a situation where oil is not an option, a water-based product can be used but just be aware that you may still see tannin bleed through. The better the quality of your stain blocking primer the better the results you’re going to have. Shellac based products also work exceptionally well for this purpose but, again, they have a strong odour.
And please, PLEASE, remember to do adequate surface preparation! Make sure the substrate is dry, remove or repair any sources of moisture. Clean, repair, sand, dust. Apply. See our bog post Be Prepared; A Surface Story for further information on adequate surface prep.. We also discuss prep in Episode I; The Blistering Menace.
For new wood or bare wood there are wood cleaners and brighteners that can help remove some of the tannins from the surface. At the design centre we carry Cloverdale Paint’s Sharkskin Wood Cleaner and Brightener and have been getting some great feedback. In fact, I’ve used it myself and it does an amazing job!
Mildew presents itself as black, grey, green or brown spots on the paint surface and is a result of moisture existing on the surface for an extended period. If the area being painted is always damp and gets little to no sunlight or if mildew has been painted over before chances are these ugly spots are going to show up at some point.
Mildew can be removed by washing with a bleach and water solution of 3 parts water to one-part bleach. Scrub the affected area with the solution and let it remain on the surface for 10-15 minutes then rinse with clean water. Be sure you are wearing protective clothing and gloves and using eye protection when working with the bleach solution. Sometimes a good cleaning is all you will need to get rid of this type of discoloration, but on the other hand the mildew may have left behind deeper stains. If that’s the case, then you’ll need to prime. Guess what type of primer you’ll need? I’ll give you three guesses, but you’ll only need one…
That’s right! Stain blocking primer!
But, in this situation, it’s best to use a latex product. Oil based products can promote the growth of mildew if any spores were missed in the cleaning process. Make sure the products you choose are high quality and are mildew resistant. A lot of today's quality acrylic paints have additives that make them especially resistant to mold and mildew but be sure to check with your customer service representative when making your purchase. Or stop in here at L.A. Design Centre and I can help you out.
Now that we’ve settled your fungal problem…
Smoke and water stains.
Nasty, ugly, brown, brownish-yellow, grey or black stains or discoloration. These stains are self explanatory. They are a result of water damage do to flooding, leaking or busted pipes, a leaky roof etc. or they are due to a fire or smoking cigarettes or cigars in an area over an extended period.
Hmmm…. Think you got this figured out yet?
1. Adequate surface preparation.
2. Stain Blocking primer!
When it comes to getting rid of water stains the first step is to make sure the reason the stain happened in the first place is taken care of. Find the source of the water and do any repairs if needed. Clean the surface with a good degreaser and give it a rinse. If it’s a large or particularly dark stain I like to hit it with the bleach solution we discussed earlier, just to be sure there aren’t any mildew spores hanging around. After being sure you’ve done adequate surface prep you can apply your stain blocking primer and you are ready for your new top coat.
Smoke stains, whether it be from a fire or tobacco need to be cleaned with a good degreaser as well. I guarantee there is going to be soot or nicotine residue that’s going to stop you new paint from adhering properly. After a good washing, rinsing and any other (I’m going to say it again and again until it’s drilled into your brain) needed surface preparation it’s a pretty good bet that things are still going to look discolored. Enter your trusty stain blocking primer. Apply a nice even coat over the staining and BAM! Bob’s your uncle! You are ready to paint.
One thing to remember when selecting your primer for those ugly water or smoke stains is that, just like with wood tannins, an oil based (alkyd) is going to be the better choice. Its superior stain blocking capabilities are going to seal the stain and prevent bleed through better than a latex. Obviously, you can use water based if oil is just not feasible but know that you may still get some bleed through.
Dealing with stains and discoloration is simple. Do your surface prep, use an appropriate, high quality stain blocker and topcoat with a high quality paint and you’ve got it covered.
And tell Uncle Bob to stop smoking in the house.
Next time on Paint Problems…