Bloedend hout: een pleister op de wonde!

Bleeding wood: a plaster on the wound!

Bleeding wood refers to the phenomenon whereby the dyes or stains from the underlying material penetrate the paint layer and become visible on the surface. The phenomenon can occur when you use water-based paint on certain surfaces.

1. Why wood bleeds

There are several reasons why bleeding may occur:

  • Water-soluble dyes: Some materials contain dyes that are soluble in water. When you apply a water-based paint, the water in the paint can activate and bleed the dyes of the underlying material.

    The most common reason for bleeding wood in this category is wood that has been exposed to pollution such as smoking for a long time. Smoking can lead to the buildup of nicotine and other substances on surfaces, including wood. These substances can penetrate through the paint layer and become visible as stains or discolorations, resulting in so-called bleeding.

    When you apply a water-based paint to wood that has been exposed to smoke, there is a risk that the nicotine and other contaminants in the wood will dissolve in water and bleed through the paint film. This can result in yellow or brown spots that damage the paint layer.

  • Tannins: Wood types such as oak, mahogany and pine contain tannins, natural substances that are soluble in water. When you use a water-based paint on wood with high tannin levels, the tannins can rise to the surface and bleed through the paint layer.

  • Oily stains or residue: If there are oily stains or residue on the surface before you apply the water-based paint, the water-based paint may have difficulty adhering to it properly. This can result in bleeding of the stains through the paint layer.

2. Stop the bleeding

If you notice that your wood is bleeding after your first coat of paint, there is no point in applying a second or third coat of paint. The stains will be passed on to the next layer again and again. You will therefore have to take another action to prevent the stains from showing through. Fortunately, there are solutions! To prevent or minimize bleeding, there are some steps you can take:

  • Surface Preparation: Make sure the surface is clean, dry and free of oily stains or residue before applying the paint. Clean the surface thoroughly and sand if necessary to promote good adhesion.

  • Using a primer: Applying a suitable primer can help prevent bleeding. An oil-based primer or special bleed blocker can be effective at isolating the dyes or tannins in the underlying material. The primer we offer is suitable to stop and prevent bleeding. A water-based primer is not suitable, as this primer will pass on the stains just like the water-based Chalk Paint.

  • Testing: It is always wise to paint a small test area before treating the entire surface. This will allow you to check for bleeding and take the appropriate steps to address the problem before proceeding.

  • It is important to note that bleeding is sometimes difficult to completely prevent, especially on surfaces with high tannin levels. In some cases, it may be necessary to apply multiple coats of primer or use special bleeding blocker products to solve the problem.
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