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3 Tips for Painting over Polyurethane or Varnish

Read this before you paint "unfinished" IKEA furniture or previously stained pieces! That clear coat makes painting over polyurethane or varnish impossible unless you follow these three simple tips!

How to Paint Over Clear Top Coat so it Doesn't Peel

There's nothing worse than putting hours of effort into painting a newly acquired piece of furniture, only to have it scratch and peel off at the slightest touch! With some prep work and these simple tips, you can successfully paint over polyurethane or other finished wood and give your furniture or trim a whole new look!

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Refinishing old furniture is a great way to keep it out of the landfill and give it new life. But it can take a lot of work to make it look great again! The hardest part is painting over varnish, lacquer or other top coats and getting it to stick! Trust me, I've been there!

I recently bought what I thought were unfinished IKEA Trofast drawer units for my son's IKEA Lego table. Little did I know, but they had a clear coat of varnish over the raw wood! I didn't realize it until I had applied the first coat of paint, which scratched off under my fingernail easily.

red paint scratched off by fingernail

So frustrating! The only way to fix it was to sand off all the paint and try again (or if you're lazy like me, just buy a new one!) With the right preparation, the paint turned out beautifully!

two IKEA Lego tables made from IKEA Trofast drawer units, made to look like giant Lego bricks

Another problem that can arise when painting over varnished wood is that the tannins can still bleed through, leaving you with a blotchy finish. Oak is the biggest culprit, and can make white paint turn orange over time!

When I painted my ugly melamine cabinets with oak trim, I found that the grab bars and side panels weren't as crisp white as the rest of the doors. It took a coat of the right primer to block the tannins from bleeding through.

before and after photos of painted lower kitchen cabinets

Want to learn my tricks? Here's how to successfully paint over polyurethane or other finished wood!

Sand off the old finish

I know, I know, no one likes to sand! It's one of my least favorite tasks in any DIY project. But the easiest way to remove that shiny top coat of lacquer or varnish is to rough it up with some sandpaper.

orbital sander removing old stain from tabletop

Sanding is especially important if you plan to stain the wood a different color instead of painting it. The stain can't be absorbed into the wood if there's a layer of protective coating on it!

When I refinished my dining table, I used progressively finer grits of sandpaper to restore the wood to a smooth finish. With just a few passes of the sander, all that yellowed varnish was removed (along with scratches, dents and gunk)!

dining table in process of being refinished

But how do you sand curved pieces or intricate details? Try these contour sanding grips for things like spindles or round table legs.

contour edge sander

For sanding in concave curves or holes, I like to use a drum sander attachment on my drill or Dremel.

Use a Dremel with a sanding drum attachment to get into the bite marks of your watermelon decor.
Using a drum sander to sand inside of handle of DIY Lego bin

Use a deglosser

So you want to paint furniture without sanding? Then you need this stuff! Deglosser is basically liquid sandpaper. It's great for all those nooks and crannies or intricate details, or if you have a large piece that would take forever to sand.

The chemical will etch the varnish and allow paint to adhere. However, it is a pretty powerful chemical, so make sure you use the proper eye and skin protection!

Rustoleum Cabinet Transformations deglosser on pine wood background

It's always a good idea to test the deglosser on an inconspicuous area of your project first to make sure it doesn't ruin the wood. To apply, just saturate a lint-free rag with the solution and wipe it over the surface. Let it dry, then you're ready to paint! You don't even have to rinse off the deglosser first! Bonus!

When I painted my melamine cabinets, I used the deglosser in the Rustoleum Cabinet Transformations kit to clean and rough up the surface for painting. I was worried that the paint wouldn't adhere to the slick plastic laminate, but it worked like a charm! After two years, it still looks great!

painted melamine cabinets with oak grab bars with new hardware

Apply a bonding primer

My final tip for painting varnished wood is to use a high quality bonding primer first. Not only will it ensure that your paint will stick, but it will take less coats to get full coverage! I've used two types of bonding primer for different situations.

Zinsser B-I-N primer is a shellac based primer that will stop tannin bleed in its tracks! It requires mineral spirits to clean up, so be sure to keep some on hand for any potential spills or drips. This is what I used on the oak sections of my kitchen cabinets.

The other primer I recommend is INSL-X Stix bonding primer. This stuff will stick to anything, including tile! It's what I used when I painted my tile floor and the IKEA Trofast drawer units, and it's held up amazingly well!

INSL-X bonding primer on tile floor

For the best finish, give the primer a quick sanding with 220 grit sandpaper and clean off the dust with a tack cloth before starting to paint. This will remove any brush strokes and give you the flawless look you want!

Now that you know how to paint over polyurethane and other clear top coat finishes, you can tackle that piece of furniture that's been sitting in the garage for ages!