Cardboard is a useful and versatile substance, and it’s one that a lot of people use in both craft projects and DIY situations. Cardboard can be used to temporarily cover up imperfections, create screens, or as part of a display, and it is consequently a very popular material for all sorts of situations.
However, cardboard is not attractive to look at in most cases, and if you’ve got big sheets of it, you might be wondering what the quickest and most effective way to change their appearance is. Cardboard is sensitive to water, which can make painting it tricky. Can you spray paint cardboard, or is this not a viable solution?
Can you spray paint cardboard? Spray paint is an excellent way to cover cardboard, and it can be applied quickly and easily in most cases. It is important, however, to keep the can well away from the cardboard while spraying, so you don’t get too much moisture into the cardboard and end up making it warp. You should also shake your spray paint thoroughly first.
Will Cardboard Stand Being Spray Painted?
Spray paint won’t harm your cardboard if you use it correctly. That means you need to hold the can at least 12 inches away from the cardboard, and make sure you are only spraying it lightly. The thinner and lighter the first coat is, there less chance there is that it will cause the cardboard to warp. You can add further coats once it is dry.
Remember that cardboard will very quickly show signs of damage if it gets too wet. Spray paint contains quite a lot of moisture, so if you spray a lot onto the cardboard all at once, it will cause the cardboard to expand and may result in it losing its shape and integrity. Cardboard is not good at dealing with water.
However, if you make sure you are spraying the paint from a good distance and you are not spraying too much on at once, this shouldn’t be an issue. Make sure you are always moving the can as you spray, so that the paint is being directed at new cardboard constantly, and allow each coat to completely dry before you add the next one.
Follow the manufacturer’s directions for spray paint drying times. Spray paint can dry much faster than other kinds of paint and may be touch dry in just 30 minutes, but you should wait longer to ensure sufficient water has evaporated from the card before you add more.
Do You Need to Prime Cardboard Before Painting It?
Priming cardboard before you spray paint it can be a great way to reduce the risk of it warping. The primer will cling to the surface of the card and give it some protection from the moisture in the spray paint, minimizing the risk of damage. It will also improve the paint’s adhesion, giving you a coat that will last.
Gesso is a popular primer for cardboard, as it provides a textured surface that the paint will stick to. It also provides moisture resistance, and it will give you a plain, white surface to work on. This might improve the color of your spray paint, because you won’t be trying to cover up the natural brown hue of cardboard.
Apply the gesso to your cardboard using a brush, and then allow it to dry. This will usually take about 24 hours, so don’t rush this process. The gesso should then be sanded down to provide a smooth, porous surface for your paint. It is a textured substance, so sanding will be key.
Use 500-grit sandpaper, and sand lightly to avoid any risk of damaging the cardboard.
You can then put down protective cloths, ventilate your working space, and apply the paint. Remember to wear a mask and goggles, and to avoid working in an enclosed space if possible, because spray paint contains harmful chemicals that could be dangerous if you breathe them.
How Many Coats of Spray Paint Do You Need?
You will generally need at least 2 coats of spray paint on your cardboard. The first coat will usually be patchy, especially if you are applying the paint very thinly. The second coat will fill in the gaps and create a smooth surface of solid color. In some cases, you will need a third and even a fourth coat of paint.
This will ensure you get good coverage without having to spray a lot of paint on at once. Remember that adding too much paint in one go will frequently lead to the cardboard curling. You must be patient when spray painting, and avoid the temptation to spray a thick layer of paint on. Thin coats will give you the best results.
What If the Cardboard Starts to Warp?
If you see signs of your cardboard warping, you will need to stop spraying it immediately. This indicates you have got too much moisture in the cardboard, and it is losing its structure. Flatten it as best you can and leave it to dry out completely before you do anything further with it.
When you return to the cardboard, check whether it has flattened, and then you can resume painting. This time, however, make sure you are keeping your paint can far enough away from the cardboard, and only applying a thin stream of paint at a time.
Remember that each coat must be allowed to completely dry before you add the next one. If the paint is still wet, there’s a high chance that the cardboard will warp, but this could also cause the paint to bubble and start peeling off. Leave the cardboard for around 24 hours (or according to the manufacturer’s instructions) before adding more paint.
Final Thoughts
Spray paint is a great way to quickly change the appearance of large pieces of cardboard, but it must be applied with care, or it will ruin the cardboard. Cardboard warps and curls when it gets wet, so keep your project safe by only applying thin layers of paint and allowing it to dry completely between coats.
