Sanding Veneer – Avoid Burn Through!
Most furniture which I pick up in the Netherlands is veneer. I would estimate 95% of the quality pieces I have come across is veneer. It’s rare to find furniture made from solid, hard wood with impressive wood figuring. So, it quickly became apparent to me that I would need to learn how to Sand Veneer and avoid burn through.
Unfortunately, when I first started, I was not always so lucky. I either guessed incorrectly that the piece was solid wood or underestimated the power of my electric sander. Burning through veneer was a tough lesson for me to learn.
What is Veneer and Why Does it Require Care When Sanding?
Veneer is simply a thin sheet of wood that is glued onto a substrate. Often the substrate itself is solid wood, plywood, or chip board. Ornate wood figures can be very expensive. By slicing the unique wood thin, you can cover a larger amount of furniture than building it from solid wood.
Veneer permits creating gorgeous furniture with unique grain patterns for a fraction of the cost if it was done with solid wood.
The thinness of veneer differs. It is usually less then 1mm in thickness. This is why prep work for furniture refinishing will differ between veneer and solid wood. Sanding veneer must be done very carefully to ensure you do not blow through the veneer layer into the underlay beneath.
Not sure where to begin with veneer refinishing? Check out this full beginner’s guide to refinishing veneer furniture.
What is Veneer Burn Through
You will often hear the term Burn Through on social media, but what does it actually mean?
When sanding the thin layer of Veneer, you can easily sand right through the veneer. Which means you have sanded the veneer away and now can visibly see the substrate underneath.
Since the substrate is a different type of material, any finish, including wood stain, will react differently to the two materials (the veneer and the substrate). Which will cause the spot to be noticeable.
Why Should You Even Sand Veneer?
If sanding veneer is so dangerous, then why even bother to sand it?
Well; veneer is still wood, despite its thinness. Sanding is essentially the process of smoothing and polishing the surface. By smoothing wood of all scratches, dents, and blemishes, you are limited the chances of blotchy staining or marks on your painted surface. Furthermore, sanding wood will help products to adhere to it better.
However, if not done correctly, sanding can make your wood surface worse. Marks and swirls created by incorrect sanding will be highlighted by your further treatments of the surface.
Correct sanding, knowing how much to sand and when to stop are important knowledge to learn as furniture refinishers.
Before You Start Sanding Veneer
Sanding veneer is a different process to sanding solid wood. With solid wood, you can usually spend longer on each grit — even with an electric sander — without worrying about sanding right through the surface. Veneer, however, is far less forgiving.
Your sanding method should depend on two things:
The condition of the veneer, and
Your end goal — whether you’re painting the piece or planning to showcase the wood grain.
If you’re planning to paint, a light scuff sand is usually all you need to help your primer stick. But if you’re aiming to stain or clear finish the veneer, you’ll need to be more methodical and precise, ensuring a smooth and blemish-free surface.
Before you begin, inspect the piece carefully. Is the veneer in good enough condition to sand? Does it have any bubbles, chips, or lifting areas that need repairing first? Attempting to sand over damage will likely make things worse.
TIP: Not sure if you’re using the right sandpaper? Check out my guide to the differences between European and American sandpaper grits.
Make Veneer Repairs
Before you start with sanding your veneer, you should first inspect the piece for any damages. Specifically, you should be looking for chipped, lifting veneer or bubbles in the veneer. If any damage is found, you need to first make repairs to these areas to ensure that you do not do further damage when you start to sand.
Sanding any lifting or bubbling veneer will simply make the problem worse. Each veneer damage will need to be treated in a separate manner. Research before you start.
Remove old Finish
Another important step to sanding veneer is removing the old finish. This can be done via a chemical stripper or carbide scrapper. You should not simply sand the old finish away. Sanding the finish can be difficult and if you incorrectly estimate when to stop, you will go through the veneer.
Chemical Strippers
There are a variety of chemical strippers on the market available for you to try. When picking one, read the safety guide and instructions and follow them! Check out this handy how to guide for all your paint stripping needs.
I will not go into depth on how to apply the stripper as each one can be a slightly different process. My tip here is to work with a plastic scrapper on veneer. When you are removing the stripper, you do not want to scratch into the thin veneer.
With a metal scrapper, you can easily gouge into the thin veneer, leaving scratches which will be difficult to sand out.
Clean your piece thoroughly after stripping and then proceed to sand when dry.
Carbide Scrapper
There are risks working with a Carbid Scrapper on thin veneer, but it is personally my preferred method to remove old finishes. I am not a fan of working with chemical strippers due to the smell.
Ensure your scrapper is sharp as a dull scrapper has more chances of slipping and gouging the thin veneer. Work where possible with the wood grain and take your time. You want to remove as much of the finish as feasible before going onto sanding.
I personally use a Bahco Scrapper and haven’t looked further. It fits well in the hand and the blades can be sharpened.
Sandpaper Grit for Veneer
When sanding veneer, your starting grit is very important. A Lower Grit sandpaper, such as 80, will go through your veneer much faster than a higher grit.
For this reason, never start with a sandpaper below 120 grit. Slow and steady is the way to win at sanding veneer.
I have a Festool R90 and swear by it for veneer. Use the Festool sandpaper, lower speed and set your sander for fine material.
Step by Step Guide for Sanding Veneer
I’ve followed these steps for the last few projects of mine and have been very happy with the lack of burn through. Practice does make perfect! If you are unsure if you are sanding to much, stop! It is better to being on the side of cautious when working with veneer.
Tools you will need
- Sandpaper – 120, 180, 240 grits
- Tack cloth or damp cloth for removing dust
- Sanding Block
- Pencil
- Electric Sander (one that you can control speed)
- Vacuum (if using an Electric Sander)
- Safety Equipment
For more useful sanding tools, check this out.
Step by Step process
The process for sanding veneer is similar to sanding solid wood in general. The key difference is that you have less thickness to sand at. Therefore you must take your time and don’t rush any step. You want to avoid sanding unnecessarily.
Preperation
You first need to clean your piece and repair any damage. Sanding loose or bubbling veneer will only cause more problems.
Then you will want to remove any old finish from your piece.
Use your Pencil
Take your pencil and lightly draw lines across the surface you will be sanding. By drawing a light pencil line, when you sand you will know that you already went over that section and can avoid going over it again.
Pick your Sandpaper Wisely
I usually start with 180 grit sanding paper on veneer that was previously finished or raw, new veneer. Veneer is normally pre-sanded and smooth. It is light grit and will not sand away a large amount of the wood fibres.
As furniture has already been sanded and finished once, you will often need minimal refinishing again.
However, if you have stripped your piece and you find that there is finish remaining or the wood grain was lifted by the stripper, you may need to even start a lower grit, 120.
For small surfaces or areas with curves
Opt for hand sanding when you are working on a small surface or areas with curves. You will have better control of the sanding process and putting the extra effort into hand sanding will result in great results.
To sand by hand you must use a sanding block or other form which will provide you with a flat, surface. Wrap your sandpaper around the form and apply equal pressure across the surface as you move the sandpaper in the direction of the grain.
Sanding large, flat surfaces.
Sanding veneer with an electrical sander is possible. You will have the most success on a larger, flat surface.
It is important that you can set your sander to a slower speed. In the case of my Festool RX 90 you can choose an option for delicate sanding. The speed and movement is than reduced.
Do not put any pressure on your sander. This is bad practice for sanding in general. It causes swirls and dips in your wood surface. Furthermore, you want your sanding surface to be flat on the surface of the wood. Do not tilt your sander.
Work with the wood grain, slowly removing the pencil marks you left on the surface of your project.
Vacuum Extractor
When sanding with an electric sander, ensure that you have a vacuum attached. It will remove the dust you create and not sand it back into the veneer itself. It will keep your work surface clear to see if you are removing the pencil mark.
Approaching the Edges
As you approach the edges of your piece, you should switch to hand sanding. The edges of veneer are always the first part which will burn through. This is especially easy with an electrical sander as there is a tendency to roll over the edge or put more pressure as you pass over it.
Check your progress after each grit
Once you have sanded away your light pencil mark, check your progress. Are there any areas which look lighter or the wood grain seems to disappear? Stop sanding! It could be a spot where the veneer is thinner and threatening to burn through.
Clean Between Each Grit
Clean the piece with a tack cloth or damp cloth. Removing dust is an important step to minimize any debris which could scratch up the surface as you sand.
Start with your Pencil Again
Before you start with your next grit, use your pencil lightly on the surface, then repeat all steps with your next grit.
Which grit should you stop at?
After finishing with 180 grit you may want to stop here if; the wood grain is already closed enough for your tastes or you wish to stain the wood.
If you want to close the wood grain further or are painting the wood, you may wish to repeat this step with 240 grit sandpaper.
Frequently Asked Questions
Yes you can! I do frequently. The key is to watch your progress carefully and stop if you feel that the veneer is getting thin.
The trick to using your electric sander is to ensure your speed is set to medium only and if you have the option to choose delicate surfaces, then please do.
If you do sand through the veneer, then you have a few options available to you. Small sections can be masked with special markers or blending sticks and toners. Mohawk blendal sticks and toners I have seen used with great results. Unfortunately these products are not available where I am. I use a variety of wood grain markers or even acrylic paints.
You can also opt to simply replace the veneer which you have sanded through.
It’s not always easy to tell — but there are a few warning signs. If the veneer has already been refinished once or shows uneven colour, patches, or wear, it may be close to sanding through. You can also try looking at an exposed edge (like the back or underside) to see the actual thickness of the veneer layer.
When in doubt, avoid aggressive sanding. Start with a higher grit (like 180 or 240), sand lightly by hand, and keep checking your surface frequently. The pencil trick — drawing light lines over the surface and stopping once they disappear — is one of the safest ways to monitor your sanding and avoid burn-through.
Final Thoughts
Sanding veneer seemed impossible when I first started refinishing furniture. I ‘ve had to change a few design plans due to burning through the veneer. But practice definitely makes progress and getting over the fear of burning through your veneer will open so many design possibilities for you.
