How to dry wood slabs?

Approx Reading Time: 8 minutes

In this blog post, I will discuss a simple yet interesting method to dry wood slabs.

A wood slab can be used as a kitchen countertop, office countertop or, the surface of your table. A wood slab will add an attractive and rustic look to your bedroom if you use it as a hanging bedside table. An exotic wood slab can also be used as an enjoyable bench or swing in your backyard.

How to dry wood slabs:

  • Step 1. Dip the slabs of wood into Pentarcryl:
  • Step 2. Dip the slabs of wood into wood sealer:
  • Step 3. For thin slabs, use denatured alcohol:
  • Step 4. Apply the salt paste on the wood slabs:
  • Step 5. Select a suitable place for air-drying:
How to dry wood slabs? 1
(CC BY 2.0) by IndoGemstone

In Asian countries, butchers use a thick slab of wood to chop the bones of the animal. A thin slab of wood can be used as a regular vegetable cutting board which can be displayed in your kitchen by hanging it along the walls to give your kitchen a beautiful look. A wood slab fixed vertically along the wall of your bar can be a beautiful wine rack to organize your bottles and keep them handy.

To add a romantic and rustic look to your bathroom, you can use a thick slab of waterproof wood as your sink or bathtub. Wood slabs look very beautiful when used as a frame of the mirror or as a lighting fixture or as a sliding door. They also look great when used as a dining table, dressing table, study table, TV stand or, a stool.

Wood slabs have no man-made seams, they rely solely on the diameter of the tree for size, so they give your home a breathtakingly beautiful look. Staircases and outdoor bird bath fountains can also be made out of a thick waterproof slab of wood. Wood slabs when added to a fireplace, chimney or, the deck look gorgeous.

A bed headboard made up of natural wood slab makes your bed look rustic and wonderful. Wood slabs look great when used as shelves either inside a wardrobe or along the walls of your bar, TV lounge, kitchen, shed, garage or, even bathroom.

Step by Step Guide to dry wood slabs

● Step 1. Dip the slabs of wood into Pentarcryl:

Pentacryl is a specially formulated wood stabilizer that is manufactured to prevent green or fresh wood slabs from cracking as they dry. If your wood slabs were recently cut and have not had a chance to air-dry yet, you must fill your container with Pentacryl to soak your wood slabs. You must pour enough Pentacryl to fill your container about halfway to ⅔ full so it cannot overflow when you add your wood slabs into it.

● Step 2. Dip the slabs of wood into wood sealer:

If your wooden slabs were cut and left to dry for longer than a few days, you must use wood sealer as a soaking solution to help prevent them from cracking or splitting from forming. You must fill the container just over halfway so you can submerge the wood slabs without overflowing the container. Wood sealers that are commonly used to prevent wooden slabs from cracking as they dry include Wood Juice and Anchorseal.

● Step 3. For thin slabs, use denatured alcohol:

Denatured alcohol, also known as wood alcohol, is pure ethanol with additives that make it toxic to consume. Thin wood slabs soaked in denatured alcohol will dry without shrinking so quickly that cracks form. You must fill your container just over halfway full with denatured alcohol so you can soak the wood slabs without the liquid spilling over the sides of your container.

● Step 4. Apply the salt paste on the wood slabs:

Salt is a natural drying agent that will help remove the moisture from the wood slabs while also reducing the speed that the wood slabs shrink as they dry. Using salt is a simple way to help prevent cracks from forming as the wood slabs dry without using harsh or pungent chemicals. You must mix three pounds (1.4 kg) of table salt with one gallon (3.8 L) of water.

After you have added the salt and stirred the mixture, you must leave it to stand for a few hours so it can further combine with the water. Then, you must add about one cup (125 g) of corn starch at a time and stir the mixture well. You must continue adding corn starch until it forms a thick paste that is about the consistency of oil paint or cake batter.

You must slowly pour in the egg whites and stir it well to combine them. You must continue mixing until the egg whites disappear into the paste to help keep it from flaking as the wood slab dries after you apply it.

● Step 5. Select a suitable place for air-drying:

You must choose a spot where the slab can remain for the extended time required. You must use the formula of 1-inch of thickness per year for the curing time. You must place the wood slabs out of direct sunlight, fog, dew, haze, hail, rain, and snow.

You must place the wood slab upright, off the ground, leaning it at a 30-degree angle to provide airflow behind it.

When is a wood slab ready to use?

A wood slab is ready to use after the completion of the following 10 processes:

● jointing

Flattening one face of a wood slab and squares up an adjacent edge, if removing the live edge side.

● Planing

Bringing a wood slab to a consistent thickness by flattening the other side of an already jointed wood slab.  Planing and jointing work hand in hand.

● Gluing

Gluing two or more wood slabs together, or book matching two parallel ripped wood slabs (cut along the length to make two narrower pieces)

● Pre-Finishing

A combination of jointing (or jointing and planing) & gluing, if needed, 220 grit sanding, and ready for finishing with lacquer, polyurethane, epoxy, or whatever choice of finishing you like to apply.

● Finishing

Taking where we left off with the Pre-Finished wood slab and spray it with a durable and natural feel-to-the-touch Satin Lacquer Finishing. Only the top side of the wood slab is smooth finished; the bottom part of the slab will be roughly sanded and finished. Finishing both sides of a wood slab is also an option.

● Fillers / Epoxy

Wood Fillers and Epoxy work are expensive.

● Butterfly / Dovetail Keys

To keep your wood slabs from splitting in vulnerable spots, it sometimes requires the use of Butterfly (Bow Ties) or Dovetail Keys. 

● Transportation / Delivery:

How will you be able to use a slab of wood until and unless it is moved out of the factory and transported or delivered to your place?

● Installation

Whether it involves attaching the legs or base to your finished wood slab tabletop or setting up your finished shelves, countertops, bar tops or, custom built-in design, etc, you should hire professional craftsmanship for this task.

● Retouching

Bring back that loving look to your dull looking hardwood slabs to keep them new forever.

Tips:

1. Add weight:

Cupping can be avoided by adding significant weight to the slab to keep it flat while at the same time allowing the flow of air around it. Cupping is a situation that involves the curvature of the wood slab. Cupping is caused by uneven drying; one side dries faster than the other, shrinks, and pulls the outer perimeter upward.

Regular monitoring and turning of the wood slab helps to prevent cupping. The lumber at the bottom of the stack is probably weighed down sufficiently by the wood on top of it, but wood slabs near the top greatly benefit from the added weight. Weighing the slab of wood down helps to prevent warping or distortion, which is especially important during the initial drying stage when passing through green to an ambient equilibrium moisture content (EMC).

Neatly and properly stacking, stickering, and weighing wood slabs will go a long way towards ensuring that the drying process will result in a flat, stable, and usable slab.

2. Add heat after the equilibrium moisture content (EMC) is gained:

It is very important to be patient and not to rush the drying process too quickly, but once a wood slab has safely reached equilibrium moisture content (EMC), it is really important (especially during the humid summer season) to bring the moisture content (MC) down even further for a specific project. This can be as simple as moving your wood slabs from your garage or your shed into your heated basement indoors. In cases where thinner slabs are being dried, a drying cabinet can be used to gradually reduce the moisture content (MC) down to twelve percent moisture content, to six percent moisture content, or any other level required.

A drying cabinet is nothing more than a simple wood cabinet with an incandescent lightbulb on a dimmer to finely control the light output—which in turn dictates both internal temperature and consequently relative humidity (RH).

3. Cut the wood slabs slightly oversized:

wood slabs shrink as they dry out. This, along with the material that will inevitably be lost when the wood slabs need to be jointed/planed smooth, means that greenwood should always be cut larger than the desired finished thickness.