Brown stains coming through a primer can be an issue, but it is not necessary to replace the entire surface. The brown stains could be due to various things, but the most common one is the presence of tannins in the wood, making them appear in lighter colors and through the primer. The best solver is a second primer.
Stains can be a pain and difficult to tackle. On the other hand, painting is not direct. A light color may expose stains due to different reasons. Therefore, it is important to understand their causes before developing a strategy.
With wooden surfaces, brown stains coming through the paint are common. However, it needs immediate action. So, adding coats to the surfaces while being meticulous with the coverage is one way to achieve results.
This write-down will look at various causes, how to fix the brown stains, and what you can use.
Table of Contents
Brown Stain Coming Through Primer: What Could be the Causes?
Stains being a major concern for most homeowners, there are possible causes, as we explore in this section.
Tanning oil left by the vehicles or other machines that have been driving on the ground and other machines is the primary reason for brown stains.
When water is in the paint film, it causes it to dry fast, or when it is applied too thickly, water seeps via the paint’s top coat, leaving behind an unappealing brown stain on the surface.
Paint is composed of pigments, solvents, binders, and additives. The mixture may cause brown stains when it dries, but here is a detailed breakdown.
For oil-based paints, once they dry, chances are the solvents will escape leaving behind an oily residue on the surface, forming brown stains.
Paint is a liquid applied to surfaces to change the initial color. It is usually mixed with water and other components such as solvents and binders. The binder in the paint causes a brown stain, too, if there are too many solids in the paint pigment.
Lack of enough paint covering the surface area can cause brown stains. Failure to use enough paint will take longer to dry, leading to more moisture seeping through the surface before it cures completely, yielding more chances for brown stains to form.
Moisture in the Paint
Suppose the paint is improperly mixed and fails to dry before being applied to a surface completely. Alternatively, the paint consists of mildew, which causes discoloration when it comes into contact with water.
The Wrong Primer
The use of paint causes tannin stains without a tannin-resistant primer. Tannins are organic in plants, becoming more apparent as the wood ages.
Tannin-resistant primer is essential for some surfaces like redwood and cedar, which are susceptible to tannin stains.
It is another cause of brown stains that emanates from old metal surfaces that have been subjected to rain and moisture over time.
If tracked into the building with shoes or pets, dirt and other organic substances can cause stains.
Brown Stains Coming Through Paint Fix Guidelines
Apply Topcoat Paint To Minor Sections Of The Surface
The first solution is to reapply the topcoat paint to cover the brown stain while painting. In some scenarios, the primary paint layer is insufficient if the color is lighter.
Therefore, test the surface by applying the topcoat paint to a small portion of the wooden surface to see whether or not it will still stain.
Apply the top coat paint and observe how it responds as it may work out, enabling you to move on. If it doesn’t work, then continue to the next step.
Check for New Stains
After applying the topcoat, look for new stains available to establish whether or not more measures are needed. For instance, a new brown stain may pop through even as you apply a bit of topcoat in the area.
Compare the type of stain you saw before and what you’re seeing presently. It will enable you to identify what is wrong with the paint and what to do.
Apply Second Coat of Primer
Applying a second coat of primer is important to stop wood bleeding through the paint. It could be the cause you’re seeing the brown stains coming through the paint, even with the second layer of paint.
You will achieve additional coverage on the wooden surface by doing a second coat primer.
Ensure you evenly apply the primer to ensure it settles perfectly on the surface to guarantee a fine look once complete.
Let it Cure for Longer
If you want the best results, let the second primer dry for 24 hours before painting. It is imperative to let the primer settle. Old timelines may work on the surfaces but not the same on wood.
You cannot afford to paint on a wet primer when it comes to wood, as the brown stains will begin to come through. Therefore it is a great concern when the primer is wet, and you spread fresh paint on top of it.
The Water-based primer works just great on sealing bleed-through projects, which works amazing just as shellac. You can follow the process of applying shellac with primers of your choice.
You can also seal the brown stains with shellac. One or two coats of shellac will seal in whatever is causing the bleed-through, allowing you to paint your creative designs on your piece of wood.
With a good bristle brush, apply a thin coat of shellac, then let it dry before you proceed with your painting.
For the already painted surfaces, apply shellac on top of the paint; apply another coat or two of paint over the shellac.
Ensure you apply shellac on the whole piece and not on the affected spots. Paint responds differently to the areas where shellac is applied. As a result, you will get a uniform look without bleed-through.
In a nutshell, it is paramount to take time when brown stains come through the primer. It is best to apply a second coat of paint; if it doesn’t cover the stains, apply the second coat of primer.
Let it cure for a whole day to ensure the stains disappear, resulting in an even coverage. By doing so, you will be sure to eliminate brown and other stains. Just follow the guidelines for a perfect seal of stains.