Common Wood Finishing Mistakes (and How to Avoid Them)

At KJP Select Hardwoods, we've seen many beginners - and even experienced woodworkers - encounter issues that could have been easily avoided with the right preparation and knowledge.

Let's cover the most common wood finishing mistakes and how to sidestep them so your next project gets the flawless look it deserves.

Mistake #1 - Skipping Proper Sanding

One of the most frequent mistakes we see is rushing through or skipping sanding. Finishing can't hide poor surface preparation; it highlights it. Uneven sanding, swirl marks, and scratches will appear loud and clear once the stain or finish is applied.

Avoid it by:

• Sanding with progressively finer grits (start with 80–120 and work up to 180–220).
• Always sand with the grain to avoid visible cross-grain scratches.
• Use fresh, sharp sandpaper for consistent results.

In our showroom and online, we stock high-quality abrasives that help you prep your surfaces like a pro. If you still feel like a fish out of water, our team can also walk you through which grits are best for your wood type and project.

Mistake #2 - Not Thoroughly Cleaning the Surface Before Applying Finish

Even if you've sanded perfectly, leftover dust, oil from your hands, or unseen debris can ruin your finish. Applying stain or sealant over a dirty surface results in blotchy, uneven coverage or fish-eye patterns.

It's also important not to sand other projects near something that's in the process of finishing. At KJP Select Hardwoods, we have a closed-off room with doors intended solely to keep dust away from our finishing and drying projects.

While this may not be possible for everyone, keeping dust away from our finishing projects remains just as important.

Avoid it by:

• After sanding, vacuum and wipe the surface with a tack cloth or a damp rag.
• Wear gloves when handling the piece after sanding.
• Use a raw wood cleaner or wood preparation product after sanding.
• Denatured alcohol or mineral spirits are used for a final clean, depending on the finish.

Mistake #3 - Applying Too Much Product at Once

More is not always better, whether stain, oil, or polyurethane. Overloading your brush with the product or applying thick coats can lead to runs, drips, and an uneven sheen. It also significantly increases drying time and can trap dust or bubbles under the surface.

Avoid it by:

• Using thin, even coats.
• Applying multiple light layers rather than one heavy one.
• Allow each coat to dry fully before applying the next.

Mistake #4 - Not Following the Manufacturer's Drying Times

Another common mistake is rushing through the finishing process by not allowing enough time between coats. While reaching the finish line and finally seeing your finished project in all its glory is an exciting concept, hurrying through this process can affect the finished product.

If drying times aren't followed properly, the finish can remain tacky, lead to poor adhesion, or even pull off previous layers.

Avoid it by:

• Follow the manufacturer's instructions for drying and curing times.
• Giving extra time in humid or cold environments.
• Touch-testing in an inconspicuous area before proceeding to the next step.

Mistake #5 - Not Stirring (or Over-Shaking) the Finish

Some wood finishes contain solids that settle over time, so stirring is necessary to redistribute them evenly. However, shaking a can of finish, especially polyurethane, introduces bubbles that can transfer to your surface.

Avoid it by:

• Stir the finish slowly and thoroughly with a clean stick.
• Avoid vigorous shaking or letting the can sit undisturbed after mixing.
• Straining finishes through a filter if you suspect contamination or bubbles.

Mistake #6 - Skipping Test Applications

Each wood species takes stains or finishes differently. What looks perfect on pine might appear blotchy or too dark on maple. Jumping straight into completing your project without testing first can result in unwanted surprises.

Avoid it by:

• Testing your finish on a scrap piece or a hidden area.
• Apply the full finishing schedule (stain, sealer, topcoat) during your test.
• Adjust your technique, colour choice, or finish if needed.

Mistake #7 - Overlooking Environmental Factors

Finishing in a dusty garage, a humid basement, or an overly cold workspace can ruin even the most carefully applied finish. Temperature and cleanliness directly impact drying times, adhesion, and overall quality.

Avoid it by:

• Finishing in a clean, ventilated, temperature-controlled space.
• Avoid windy conditions or open windows during drying time.
• Wear proper safety gear when using oil-based or strong-smelling finishes.