Refinishing kitchen cabinets can seem like a daunting task, but with the right preparation, you can achieve a beautiful, updated look. If your cabinets are finished with varnish, sanding is an essential step before painting or staining to help the new finish adhere properly. Here’s what you need to know about sanding varnish off cabinets before painting or staining.

Why Sanding is Necessary

Varnish leaves behind a smooth, protective coating on the wood surface of cabinets. This clear top layer creates a barrier, so new paint or stain has trouble penetrating the wood. Sanding through the varnish allows the paint to grip the raw wood for superior adhesion.

Without properly sanding off all the varnish first, the new paint can peel or chip off easily. Prepping with sanding creates the ideal porous surface the paint needs to stick to.

Sanding Levels for Painting vs. Staining

The sanding goal differs slightly depending on your finishing plan:

Painting

When painting over varnish, it’s important to sand down to the bare wood. This removes the varnish coating completely and opens the grain for the paint to hold onto.

Aim to expose a fresh wood surface. Sand until the cabinets feel rough and you see raw wood.

Staining

For staining over varnish, you’ll want to sand enough to scuff up the surface completely. Unlike paint, some stain can penetrate through light varnish residue.

There’s no need to sand down to fully bare wood when staining. A good scoring of the varnish provides sufficient grip. But be sure all gloss and sheen is dulled for stain to take evenly.

Sandpaper Grits to Use

You’ll need to start sanding with a coarse enough paper to remove the varnish efficiently before moving to finer grits:

• 60-80 grit: For heavy sanding through varnish and exposing wood
• 100-120 grit: For smoothing rough areas after varnish removal
• 150-220 grit: For final smoothing before painting or staining

Be sure to thoroughly sand all surfaces—fronts, sides, tops, trim, and doors. Pay special attention to highly varnished areas like around knobs. Consider a palm sander for flat surfaces and sanding blocks for intricate trim.

Sanding Technique Tips

Follow these tips for best results as you sand varnish off your cabinets:

• Always sand in the direction of the wood grain.
• Apply moderate pressure, but don’t overdo it. Let the grit do the work.
• Thoroughly sand edges and corners.
• Frequently wipe away sanding dust with a cloth.
• Work methodically from the top down.
• Take your time—rushing can cause uneven sanding.
• Don’t forget the cabinet interiors and shelves if refinishing the whole unit.

Be sure to vacuum up all dust when finished sanding. Wipe with a damp cloth, allow to dry completely, and you’re ready to apply primer and your new finish.

Alternative Options to Sanding

If you want to avoid the dusty chore of sanding varnish off cabinets, you have a couple options:

• Chemical varnish strippers – Brush on products like Citristrip to eat through the varnish layer. Scrape off residue with a putty knife once activated. Wear gloves and work in a ventilated area.
• deglosser – Also known as liquid sandpaper, these mild acids rough up varnished surfaces without sanding. Great for small projects. Rinse surfaces after application.

However, sanding remains the go-to method for superior results and longevity. The extra effort at the start helps ensure your painted or stained finish looks its best.

FAQs About Sanding Varnish Off Cabinets

Do you have to completely remove varnish before painting cabinets?

For the best adhesion and longest-lasting finish, it’s recommended to sand down to the bare wood when painting over varnish. The paint needs to soak into the porous wood, not just sit on top of a varnish layer.

What kind of sander should you use on cabinets?

A random orbital sander is ideal for flat cabinet surfaces, doors, and frames. For intricate areas like molding, raised panels, and cabinet edges, hand sanding with a sanding block works better.

How do you know when all the varnish is sanded off?

Test periodically by wiping a small area with mineral spirits. If the spirits soak in, you’ve sanded through the varnish. If they bead up on the surface, keep sanding. You can also gauge by looking for a change to a rough, porous wood texture.

Should you sand cabinets before or after removing doors?

It’s best to sand cabinet doors and frames while they are detached from the cabinet boxes. This allows you to sand all the edges thoroughly. Sand the doorless cabinet boxes separately.

Can I just scuff sand instead of fully sanding the varnish?

Scuff sanding doesn’t penetrate through to the wood surface. For paint to properly adhere, the varnish coat needs to be removed completely.

The Takeaway

Sanding varnished cabinets before painting or staining is a necessary step for long-lasting, quality results. Be sure to use the appropriate grits of sandpaper and sand thoroughly from top to bottom before applying your new finish. With proper prep work, you can achieve showroom-worthy kitchen cabinets.

Conclusion

Sanding through varnish before painting or staining cabinets is an essential part of the preparation process. Taking the time to remove the varnish coating and expose bare wood allows the new finish to adhere properly and prevents future peeling or chipping. Arm yourself with the right sandpaper grits, be methodical in your approach, and sand until the wood feels rough to ensure success with your kitchen cabinet refinishing project. With the right amount of “elbow grease,” you can transform your outdated varnished cabinets into a beautiful focal point of your kitchen.