How to Keep Slab Tables Flat

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If you have recently purchased a slab table, you’re probably wondering how to keep it flat. There are a few things that you can do. One of the easiest ways is to install a c-channel in the legs. After that, you can apply a stain or finish. Read on to learn more. You’ll also find out what’s involved in air-drying and kiln-drying your slab.

Installing a c-channel

One way to prevent your slab tables from warping is to install a c-channel. This c-shape steel bar fits in a recessed channel under the slab. There are several holes in the c-channel that allow the wood to expand and contract. The slots also keep the slab from warping. Installing a c-channel is a quick and easy way to make your table tops stay flat and sturdy.

When installing a c-channel to keep slab table tops flat, be sure to use a leveling jig. The leveling jig has rails that are positioned so that the mortises are cut on the same plane as the slab. After shimming the slab to the desired height, use a leveling jig to cut the mortises. You need to trace the base of each leg first, then use the jig to mark them off. Once the first base outline is marked, slide the leveling jig over the first one. Lock the plunge router when the bit touches the wood.


To keep your slab tables flat, you need to dry them to EMC (Equivalent Moisture Content) standards. While kiln-dried slabs are safer and faster to cure, air-dried slabs require an extra two years. And the old adage of one year per inch does not apply to air-dried slabs. Depending on the species, you may have to wait as long as two years.

During the drying process, be sure to place your slabs upright at a 30-degree angle or flat. Ensure there is at least four inches of air flow underneath them. Wood begins to shrink at a moisture content of thirty percent. This moisture content will differ according to species and the existing moisture content in wood. A slab’s EMC will vary depending on climate, humidity, and temperature. However, it’s safe to assume that the wood will shrink in size from thirty to forty percent.

If your slabs are air-dried, you can still put them in a kiln to treat them against bugs. To do so, place them on a flat surface with proper ventilation. You can also place stickers under the slabs to allow air circulation. This will help prevent cupping, which is the curvature of a wood slab. It’s caused by uneven drying, and air-drying prevents cupping.


There are many benefits to kiln-drying your slab table. If you’ve used air-dried hardwoods, you know that they will deform in an indoor environment. Kiln-dried woods, on the other hand, won’t deform and will stay flat. Kiln-drying hardwoods is a method used for thousands of years by furniture makers to preserve the natural beauty of hardwoods.

Drying lumber air-dried is like leaving bread on the counter for months. You’ll never get toast out of it. Toast is bread that has been treated with heat to change its properties and reduce its moisture content. After a year, toast is dry and hard and does not accept moisture as easily as before. You can use the same principle when it comes to drying slab tables. Kiln-drying prevents such problems and makes them possible to dry faster and cheaper.

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If you’re using a thin slab, it can be difficult to keep it flat. If the slab is prone to warping, sanding off the bottom might be the best option. In addition to sanding off the bottom, you might want to extend the metal channel. But don’t make the metal channel fit tightly enough. Even if it fits snugly, the slab will still try to warp if you don’t apply epoxy.

Applying a stain

Before applying a stain, make sure the live edge is completely clean. Often, these tables were made from logs that were once piled up in mill yards. Clean the surfaces of these tables using a wire brush or a paint thinner. Once the surfaces are clean, apply the stain to bring out the figure of the wood. Then, apply a second coat of finish, such as a color-matched stain.

If the finish on your slab tables is not completely dry, you must repeat the process to give it a final touch. The stain should be applied using long strokes with the grain. Use a brush or rag with a synthetic or natural bristle. You should allow the stain to sit on the wood for several minutes before wiping it off. The longer the stain is applied, the deeper the color will be.

After sanding, apply a wipe-on polyurethane to the tabletop. This product will not remove the stain completely, but it will give it a fresh look. Use a brush attachment to remove 99 percent of the dust. A tack cloth is available at home centers. To avoid over-sanding, test your stain or finish on a scrap piece of wood. Sanding lighter and harder can change the appearance of your finish.

Finishing the entire slab

Before completing the finish, you’ll want to start by sanding the slab smooth. A 120-grit sandpaper will work just fine for this task. Make sure to check the surface for wood checks. For best results, use contrasting wood species to avoid blemishes. After sanding, route mortises with two-part epoxy, which will fill the tiny voids more effectively than yellow glue.

You can also use a two-part epoxy, such as West System Epoxy. This material is flexible and can fill large holes and voids caused by pecky wood. Choose a stain color that matches the wood’s grain. If you don’t want to stain the table, you can use a clear coat to protect it. Afterwards, finish the entire slab table to keep it flat.

You can use a joint for a full-length slab, or you can cut off the live edge on both sides. After that, finish the entire slab table by hand or with a CNC machine to achieve a flat surface. Then, you’ll need to square up the edges, if you’ve cut a straight piece in it. Make sure that the cut is clean and straight, or else it’ll be rounded up.

If you want to make a slab table with legs, you’ll need to make sure they’re milled flat. If you screw the legs directly into the slab, it might cause the tabletop to rock. Finishing the entire slab table to keep it flat is a tricky task. The slab will have to be shimmed to a level plane before the mortises can be made.

Attaching hairpin legs

Attaching hairpin legs to slab tables will give them a vintage look while retaining the authenticity of mid-century modern furniture. These legs are made of steel and tend to stain carpets and clothes. For this reason, they’re typically sold with powder-coat or luxe plated finishes to prevent rust. If you’d like to use these legs on your next project, be sure to follow these steps:

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First, attach the temporary table legs. Make sure that the screws are 3/8″ away from the edges of the table. Once they’re attached, flip the table over and examine how the legs look. Adjust as necessary. Finally, screw the remaining screws to the table legs. If you’re unsure about how to attach hairpin legs to slab tables, you can download “How-To” guides to help you out.

Attaching hairpin legs to slab tables can be a relatively simple process. In most cases, hairpin legs come with a metal plate that is welded onto the V shape and with holes already drilled through the plate. If you don’t intend to remove the legs, use screws that are heavier and coarser than the tabletop. Make sure to drill pilot holes before screwing in the screws so that you don’t split the tabletop.

Next, you should trace the base of each leg’s base. If you’re not sure how to do this, you can look at a couple of other DIY-guides. You can also take the help of a leveling jig to make sure the mortises are perfectly straight. You can even attach a tabletop to an existing slab if you want to. You need to shim the slab a few inches above the rails to make sure it’s level.

Why trust Handyman.Guide?

s written by Itamar Ben-Dor, who has 25 years of experience in renovations, carpentry, locks, creation, landscaping, painting, furniture construction, and furniture renovation, works with concrete, plumbing, door repair, and more.

Itamar Ben-Dor has been in the home improvement business for over 25 years. Itamar Ben-Dor is a jack of all trades. He's worked in the renovation field for years, doing everything from locksmithing to carpentry. He's a small repairs specialist. But his true passion lies in furniture construction and renovation - he loves seeing old pieces come back to life with some new woodwork or a fresh coat of paint.

He has taken courses on many topics in these fields at professional colleges in Israel. Over the years, Itamar has also become quite skilled in gardening, carpentry, and renovations. He's worked on projects of all sizes, from massive renovations to small repairs. No job is too big or too small for him!

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