Have you ever spray painted MDF? It sucks, right? MDF stands for Medium Density Fiberboard. For those curious minds, there is a Low Density Fiberboard (A.K.A. particle board), and a High Density Fiberboard (A.K.A. Hardboard).
I don't use MDF often and the few times I have, I used a roller or brush to paint it. When I went to spray paint the letters on my Backpack and Homework Organizer, The letters were cheap ones I found at Wal-Mart for $1 a piece. I realized spraying MDF is nothing like wood. The porous nature of MDF soaks up a good deal of the paint, wasting product and leaving a blotchy finish. It is especially bad with gloss or metallic finishes. So what are you to do? Sometimes a project just NEEDS spray paint!
After about 3 wasted coats of paint on my letters, I tried something new and it worked great! I decided to try it again on a test board so I could show you what a difference it makes.
I figured, I would account for the worst-case scenario. I grabbed a can of super cheap, glossy red spray paint (also $1 at Wally World).
I tapped off half of the board, and gave it a couple heavy coats of paint.
Even with multiple coats, and my best wax-on-wax-off technique, this is what I ended up with. A blotchy mess.
Here comes the secret ingredient: Shellac. This stuff is amazing. I've talked about shellac's amazing tannin blocking ability in this post. I figured, its good at blocking things from coming up, it would probably prevent stuff from soaking in too.
I tapped off the crappy, blotchy side of my test board and sprayed one, heavy coat of *shellac on the bare MDF.
Once dry, I lightly sanded the board, wiped it clean and added two coats of the glossy, cheap paint. You can see the difference the shellac made.
Looking closely, the difference is dramatic. The paint is actually red, not a faded, pinkish color, and the sheen is even and glossy. If I wanted a mirror like finish, I could sand the paint with high grit sand paper and finish it with a high gloss lacquer.
While we're talking about *shellac, I HAVE to share what I learned about this stuff. Have you ever Googled "shellac"? Umm, do you know where is comes from? According to Wikipedia:
"Shellac is a resin secreted by the female lac bug, on trees in the forests of India and Thailand. It is processed and sold as dry flakes, which are dissolved in ethanol to make liquid shellac."
Female insect secretions people. I researched some more and it's true! Better yet, the same stuff that was used to coat wood paneling in the 60's and was pressed into records before vinyl, is currently used to coat food. You know that glossy coat on chocolate covered raisins or store-bought apples? Yep, female insect secretions.
Let's be honest, I'm not about to stop eating shiny food, but it is interesting to know where is comes from. Buy yourself a can of shellac. Its awesome stuff for a DIYer too.
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