From the archives: All About Primers 2️⃣

Submitted to Rust-O Resources

We previously ran an All About Primers Ask the Expert activity -- we're resharing this valuable information in conjunction with our Painting Prep Tips & Tricks activity. 

ANSWER: Hi ChunkyMermaid, this is a fantastic question! It can be really hard to determine if a primer is necessary or just an added step. In order to know when to prime you need to under to why prime. Primer is very similar to paint, but it has a lower concentrate of pigment (color) and a higher concentrate of resin. Resin, is what helps a coating (primer, paint, etc) stick to a surface, and seal it so the finish is uniform and last longer. If you want to paint a glossy surface, for example tile backsplash, it is best to use a primer first. This will help the paint stick to the surface without peeling.

Primers also have stronger stain blocking abilities than paint does. Stains can come in many forms: crayon, pen, water, smoke, odors, and more. Different stains require different types of primers. Oil based stains (the crayon/pen your 2 year old drew on the wall) are best hidden by water based primers; I would suggest Zinsser Bulls Eye 123. Water based stains from your leaking pipe or tannin stains from bleeding woods like redwood & cedar are best covered by oil based primers like Zinsser Cover Stain. Knots/tannin bleed in wood, smoke stains, and odor are best treated with a shellac based primer such as Zinsser BIN.

Some specific projects were I would suggest primer include painting cabinets (Cover Stain or BIN), painting IKEA like furniture (BIN), or painting anything outdoors. If you don’t prime cabinets, you are likely to see the wood bleed through and/or paint peeling after a short amount of time. Furniture made out of cheaper materials can be a great way to save money and fun to personalize, but if you don’t prime your paint will have trouble sticking and peel easily. Anything that spends an extended time outside (siding, trim, furniture, mailboxes) experiences a wide variety of weather patterns. The wear and tear of sun, rain, and snow can cause paint to crack and peel. Using primer helps the paint stick to the surface and extends the time between coats.

QUESTION: I inherited an old metal tool box that I want to spruce up with a great new coat of paint and some new hardware.  However, there is existing rust on it. I plan to sand off the rust, but am not sure if I should also sand off the old paint. And, if I should use a primer then to seal it as I may end up painting it a lighter color than the original paint.  I know that some of the Rust-Oleum spray paint that I have are a combination of primer and paint. Can you help me to understand the difference? When should I use  a combination spray paint/primer, and when should I use a straight primer and then come back with a coat of spray paint?  Thanks. Elizabeth

ANSWER: Thank you for your patience! I had to call in some back up on this question to make sure I was giving you the best possible solution. 

For this particular project, we would recommend using Stops Rust Clean Metal Primer prior to applying the desired color. This primer is designed for lightly rusted and previously painted surfaces. It is always recommended to remove loose paint and rust with a wire brush or sandpaper, but you do not need to remove any rust or paint beyond that. The surface should then be cleaned with soap and water and allowed to dry before beginning.

Paint + Primer offerings on the market today do offer convenience as they can potentially decrease the total project time. However, while priming is not always required, it does help ensure you achieve the best adhesion, coverage and durability. Using an appropriate primer is extremely important when it comes to difficult to adhere to surfaces such as galvanized steel, porous wood, certain types of plastic, PVC, porcelain or heavily rusted surfaces. For raw wood or dark-colored projects that you want to spray a lighter color, a primer can also help you achieve coverage in less coats.

I hope this helps and your tool box turns out beautiful!

ANSWER: Zinsser Bulls Eye 123 is the best primer to paint over glass. It has the best adhesion of all our water based primers, its low odor, and it’s easy to clean up. Although you can paint over it in an hour, be sure to give your entire job 7-10 days before any rough treatment. If you do decided to start using that shower on a regular basis, you are likely to see peeling due to the humidity and moisture. However, since you assured me that won’t be happening, it shouldn’t be a problem.

I wish you best of luck with your project! Don’t hesitate to reach out with any other questions!

QUESTION:  Hello. In what situation if ever would you tint your primer? I seem to remember years ago it being recommended for certain types of projects. But times have changed with innovative paint technology updates. Not sure if its a necessary consideration.

ANSWER: A good question. I’m impressed you know primers are tintable. Most people (even some store associates) don’t know that trick!

Tinting primer is a way to help enhance the depth of color in the topcoat paint and while using few coats. Less coats saves you both time and money. When deciding to tint primer it is less about the type of project you are doing and more about the color you want to achieve. I would suggest tinting your primer when you are working towards a dark color. Again, this will cut down on the number of paint coats you will need to put on top.

Another alternative to tinting would be to buy a gray primer such as Bulls Eye 123 Gray. This will achieve the same effect and can be used under a variety of different colors.

I hope this helps answer your question! Let me know if there is anything else I can help with!

ANSWER: Based off your description of the situation I am guessing you used a water based primer. Water based primers can be great for many different projects around the house, but unfortunately they do not stop bleed though on wood, very typical when painting cabinets. Bleed through is actually caused by natural tannins in the wood and water based primers will not hide these. For cabinets I would suggest using a shellac based primer. Shellac is often used by professional wood workers to seal wooden surfaces. Rust-Oleum offers a white shellac primer called Zinsser BIN. It is a Pro cabinet refinisher favorite. Another option is to use an oil based primer such as Zinsser Cover Stain.

I hope this helps! If you have any other questions feel free to send them my way!

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