Before you paint, furniture prep is just as important as the finish. Your furniture will only last as long as the base beneath the paint. Most paint companies claim no prep is needed but it’s just a generalized statement with the caveat that the surface you paint on is ready to be painted. You must clean, do whatever repairs are needed, sand if needed, strip if needed, and make sure that the paint will adhere so that a scratch with your nail doesn’t result in seeing the wood underneath. The proper cure times are essential as well.
How do you know what to use and how to use it for prep? It depends on the surface slickness. Some pieces are made of pressed wood with a lacquer or laminate over it. This causes sleek surfaces that make it difficult for paint to adhere properly. That’s when priming is a must. Primers are made to adhere to glossy and slick surfaces however even primer has issues adhering to laminate type surfaces which repel water and thus repel the primer. You will need to sand so that there is some grip given to the product you use on it. I painted a laminate surface on MDF wood. MDF looks nothing like real wood but is comprised of wood fibers. An attractive finish is needed over it. Most of the time it is a faux wood-looking laminate that can be a solid color as well. I used a primer over it and after it had dried, proceeded to paint it with a high-quality paint that claims no prep is needed. What resulted was a peeling mess. The paint would not go on evenly and streaked. No matter how many layers I tried to cover it with, it still peeled easily. I stripped it and sanded the surface with 120 grit paper. After that, I went ahead and primed then painted. The paint stuck and didn’t peel. The lesson of the story, deglossing is not enough on the contact paper like laminate nor does primer prevent paint from peeling. Sanding is a must in certain instances. You cannot cut corners trying to go around essential steps in prep.
Shellac is made from secretions of the female lac bug. It is used to seal wood for a more durable finish. It is self-leveling. It also prevents wood tannins from seeping into the paint and stains that you cannot see coming through like cup rings. It provides a solid layer like resin for stain blocking properties. Certain woods are prone to bleed through more like cedar and redwood. Back in the day when people often smoked inside their homes, the nicotine coats the furniture over time. This is another reason a thorough cleaning with a product like the Krud Kutter degreaser is important to strip off accumulated layers of nicotine and old varnish. Sanding further removes any residue. If you use a shellac-based primer like the Zinsser Bin advance primer, it will help with paint adherence, coverage, and blocking stains as well as bleed-through of tannins. The staining is especially noticeable with light-colored paints and notoriously white paint. White paint is prone to yellowing for many different factors including bleed-through of tannins. This is not to say your white paint finish won’t yellow over time due to sunlight, what you use to seal it as an oil-based varnish will certainly yellow it, and what is used to clean the furniture. Do your diligence to prevent yellowing as much as possible with the proper prep.
I often use a deglosser as the last step as it helps remove any left over varnish and helps with adherence by making the surface a bit tacky to touch. It does not replace sanding. A deglosser merely coats the surface, it doesn’t prevent staining or bleed through. It’s useful to make surfaces less glossy but if you need to sand, you must sand. I like to prime even if it’s not necessary as it helps with the coverage of paint. If you are painting with a light color, you will not need to use as many layers because the primer has excellent coverage if it’s a quality one and it comes in white or gray. You must have a good base layer with certain paints like metallics. Primers are generally cheaper than the boutique paints that are popular these days. Even if the primer is costly, I prefer to use one layer of primer and decrease the double amount of layers I need to apply using light colors. If you are painting black, it isn’t necessary to prime most of the time. You would use a gray primer if you are using cold tone colors like purple, silver, blue, and dark green or dark red. The gray brings out the true shade of the colors.
There is no shortcut to proper prep. Be mindful of what you are using and its properties. There are instances when you can just clean and paint but I prefer to be careful especially selling my furniture. I want it to last for another lifetime. Be wise in choosing the correct products and steps. Remember, the slicker the surface, the more you need to be leery of your paint peeling. For certain paints, you must use primer like with latex paint as it’s a paint meant for walls and not heavy traffic surfaces. You want to be able to clean the furniture after it’s been painted and cured. The paint should not peel or rub off when cleaning with soap and water. Extra steps will avoid extra headaches in the future of having to touch up the furniture.