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Why Emulsion Paint May Craze

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Have you seen emulsion paint crazing after it has been applied over acrylic caulk? Read on and discover some of the reasons for this paint failure. Use this information to make appropriate plans if you intend to repaint a structure.

Differences in Flexibility

Acrylic caulk is usually more flexible than emulsion paint is. Consequently, the acrylic caulk is likely to expand and contract at a higher rate than emulsion paint when there are changes in temperature. That excessive flexibility will eventually cause the emulsion paint to crack and craze in the areas which are most affected or prone to temperature variations. For instance, exterior walls which receive the greatest amount of direct sunlight will craze in the areas where acrylic caulk was used to fill cracks on the painted surfaces.


Acrylic caulk isn't as permeable as emulsion paint is. It is therefore going to be harder for paint to cure if it is applied over acrylic caulk. This is because the impermeable caulk will not allow various substances in the paint to dry at the same rate as the paint in the other places without acrylic caulk. Adding another layer of paint on this section which hasn't dried fully will increase the likelihood of crazing even if you had allowed the recommended amount of time to pass before you applied another coat of paint on the walls.

Caulk Thickness

Thicker coats of acrylic caulk can also increase the rate at which emulsion paint will craze over the surface where the caulk was applied. This is because thick layers of caulk take several weeks or even months to cure fully. In that time, various substances, such as water and the coalescent ingredients in the caulk, keep escaping into the atmosphere. Those escaping substances pass through the emulsion paint which was applied on the caulk. The paint can end up crazing if it was applied thinly over the acrylic caulk. Using thicker layers of paint over the caulk can reduce the impact of the prolonged curing time of the acrylic caulk.

As you can see, the different products which you use while preparing surfaces for painting can have an effect on the success of the repainting project. It may therefore be advisable for you to hire commercial repainting professional if you discover that the surfaces, such as exterior walls, have serious defects which need fixing before paint can be applied. That professional will select products which will not affect the appearance and durability of the paint.