How to Join Two Boards Lengthwise: 9 EASY Methods!

Ever struggled to create that perfect, seamless wood piece for your DIY project? Discover effective methods to join two boards lengthwise effortlessly!

Are you a beginner to woodworking projects and willing to learn about different techniques of joining wood?

You are in the right place. Here, I’ll talk about my experience bonding wooden boards lengthwise together which gave a strong and durable bond.

So, let’s find out, How to join two boards lengthwise?

To Join two boards lengthwise, applying wood glue along one board’s edge, aligning the second board against it, and clamping them together until the glue dries. Ensure both boards are flat and even, and remove excess glue for a clean, seamless joint. Suitable for creating wider wooden surfaces like tabletops.

But there’s a lot to know about joining woods lengthwise!

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Here I’ll explore how to join two boards lengthwise and discuss proper methods that you can try to edge joining and tips for joining two boards for better results.

Let’s jump in!

First of all, let’s have a quick look at the wood joints.

Wood Joints

Different types of joints are important and widely used in woodworking projects that offer unique qualities and applications. 

Here are some of the popular joints that are used in woodworking industry,

• Butt Joint
• Biscuit joint
• Hap-lap Joints
• Tabled Lap Joints
• Bevel-cut Scarf Joints
• Dado’s joint
• Rabbet Joint
• Dowel joints
• Pocket-hole Screw Joint

Check out the, Strongest Wood Joint Types and Uses!

What Is Edge Joining

A woodworking technique called edge joining, often referred to as edge gluing or edge-to-edge joining, is used to attach two or more boards or pieces of wood along their edges to produce a larger or longer panel.

It produces a larger piece of wood than other types of joints, allowing it to be used for larger projects. 

Edge joining boards typically work to align and merge their parts into a single straight piece.

For the edge joining you can use glue and different types of wood joinery methods such as biscuit joints, dowel joints, Lap Joints, splines, etc are used.

Let’s discuss. Stay tuned with me.

Can You Join Two Boards Lengthwise?

Yes. Joining two boards lengthwise is a common woodworking task that is frequently used in projects like tabletops, shelves, and more. 

Depending on your available tools and preferences, there are various ways to accomplish this.

How to Join Two Boards Lengthwise?

Now I’m going to share with you the best methods to join two wooden boards lengthwise properly to make a strong and durable bond.

Just keep reading!

1. Using Wood Glue

Using wood glue is the most common, easiest, and most practical solution for all woodworkers. 

Make sure you have enough wood glue because you will need to apply it in the form of a solid bead here.

For this, you will need,

• Two boards to be joined
• High-quality Wood glue
• Clamps
• Chalk
• Chisel

Here are the steps you need to follow when joining two board lengthwise using wood glue,

1. Prepare the Boards and Align the Edges

Ensure the two boards have straight edges and are flat. If not, use a hand plane to flatten or straighten the edges of the boards.

Do the edge alignment by placing the boards next to each other and the edges that will be linked should keep face up.

Also, you can match the shades and wood grains to your preference.

Draw a letter “U” using a chalk in between two boards to mark the alignment. After applying wood glue, these marks act as a guide and will be useful and easy for you to realign the boards.

2. Glue Application

One of the edges should be generously glued with wood glue.

Spread glue over the edge evenly using a brush or a scrap piece of wood.

Don’t apply too much glue. It might result in spilling over the realignment because the edges are very thin.

Also, avoid expecting any adhesive traces because they could make it tough to get it out afterward.

3. Re-Align and Clamp the Boards

Making sure the edges are straight, re-align the two boards together. For this use the ‘‘U’’ guide drawn at the beginning.

Clamps should be used to secure the boards. Along the seam’s length, apply constant pressure.

Check that the boards are straight and not bent using a square or straightedge.

When joining, excess glue can come out. Don’t worry. Just wipe it out before drying.

Let the adhesive dry as directed by the manufacturer (often 20 minutes).

4. Finishing

You can plane, sand, and polish the connected surface as necessary when the glue has entirely dried.

The remaining glue can now be smoothed out using a wood chisel. To make sure the joint is flawless and undetectable.

Pros and Cons of Using Wood Glue to Join Two Boards Lengthwise

There are benefits and drawbacks to using this method. Here are some of them.

Pros

• A straightforward technique that anyone can follow
• Glue is significantly cheaper.
• No need for any specialized tools or equipment

Cons

• Can’t bear excessive heavyweight even if it is a high-quality glue.
• Excessive glue tends to expand as it sets can result in bowing.

2. With Splines

Using splines to link two boards together strengthens and stabilizes the joint while adding a fascinating decorative element.

For this, you will need,

• Two boards to be joined
• Table saw or router
• Spline material (commonly hardwood)
• Wood glue
• Clamps
• Saw for cutting splines (hand saw or miter saw)
• Chisel

Here are the steps to follow when joining two boards lengthwise using splines,

1. Choose Spline Material

Select a piece of hardwood for the spline. It should be long enough to span the joint’s width but thinner than the thickness of your boards.

2. Make groove for the Splines

Find the splines’ locations on the boards. Although it is usually centered, you can change it if it suits your design better.

Cut a groove along the length of both boards, between the splines, with a table saw or router and a straight bit. 

The groove needs to be deep enough and wide enough to fit your spline material. Make sure that both boards’ grooves are parallel.

3. Cut the Splines

Match and cut the spline materials into pieces as they fit into the length of the grooves you cut in the boards. The spline should be thick enough to fit tightly in the grooves.

4. Glue Application

Apply wood glue to the inside of the grooves on both boards.

5. Insert Splines and clamp

Put the spline pieces in one of the boards’ grooves. Make sure they are placed evenly and snugly along the joint’s length.

Put the spline pieces in between the two boards as you join them. Make sure the joint is flat and straight before securing the boards with a firm clamp.

Remove any extra glue that leaks from the joint by wiping it off.

Follow the manufacturer’s instructions for the glue’s recommended drying time, usually 20 minutes.

6. Finishing

You can plane, sand, and polish the connected surface as necessary when the glue has entirely dried.

Use a chisel to carefully cut the splines flush with the boards if they are sticking out from the joint.

Pros and Cons of Using Splines to Join Two Boards Lengthwise

Let’s discuss the pros and cons of this method.

Pros

• Create strong joints that can bear a lot of weight or stress.
• Resists Cupping and Warping
• Splines provide an improved Glue Surface for stronger bonds between the two boards

Cons

• Specific tools are required such as saws and spline materials.
• Grooves can be visible
• Time consuming process.

3. Using Metal or Plywood Straps 

Using straps made of metal or plywood to bind two boards together gives the joint more sturdiness and strength.

Materials You’ll Need

• Two boards to be joined
• Plywood straps or Metal straps (about ¼-inch thick)
• Screws or bolts
• Screwdriver
• Drill bits
• Ruler and a pencil

Steps need to be followed when joining two boards lengthwise using metal or plywood straps,

1. Cut the Strips

The plywood sheet should be measured and cut into strips. The width of these strips should match the thickness of the boards.

2. Apply Glue and Screw the Board

Choose the location for the plywood straps you want to use for reinforcement. Normally put at the top, bottom, and center of the joint.

Place half of the strap on one board and secure it with glue and screws, leaving the other board’s half exposed.

After that, secure the board with a clamp and give it 20 minutes to properly set.

3. Attach the Second Board and Set

After aligning the edges of the two boards, attach the strap’s protruding portion with glue and screws.

Fix the second board to the strap with a clamp.

For the greatest effects, let the setup dry on a flat work surface.

Pros and Cons of Using Metal or Plywood Straps to Join Two Boards Lengthwise

These are the pros and cons of the technique.

Pros

• Added Strength and suitable for heavy loads
• No need for specialized tools
• Anyone can perform, no need for experienced individuals.
• A cheaper technique

Cons

• Limited Decorative Value due to visible screws or bolts

4. Using a Dowel Joint

Dowel joints are a traditional and reliable method of joining two boards together in woodworking. 

For this joint, opposing holes are drilled into the two materials, and the holes are filled with wooden dowels. This type of joint is used for a range of furniture pieces, including mirrors and picture frames.

For this, you will need,

• Two boards to be joined
• Pre-cut dowels
• Wood glue
• Clamps
• Drill
• Drill bit matching the dowel size
• Mallet

Steps need to follow when joining two boards lengthwise using a dowel joint,

1. Mark Dowel Locations

Choose the location for the dowels you want to use as reinforcement. Normally the top, bottom, and center are the common positions for placing dowels.

On both boards, note these spots with a pencil and a ruler.

2. Drill And Test a Hole

Drill the first hole to roughly half the length of the dowel by setting the drill bit to the diameter of the dowels.

Test the dowel after removing the wood dust. So that you can tap it into the hole with a mallet, it should fit snugly.

Complete drilling of all remaining holes for both boards, with making any necessary adjustments to the drill bit.

3. Dowel Insertion

Dowels should be inserted into one of the boards after applying wood glue to the holes.

Use glue on the wooden dowels as well if you plan to use them.

Read to know, How To Cut Wooden Dowels? (4 EASY Steps!)

4. Assemble the Joint and Clamp

Join the two boards together, ensuring that the dowels fit tightly into the holes on the other board. If necessary, use a mallet to tap the boards together.

Then mount them into the clamps and allow them to be properly set for several hours.

You can plane, sand, and polish the connected surface as necessary when the glue has entirely dried.

Pros and Cons of Using a Dowel Joint to Join Two Boards Lengthwise

Aware of the pros and cons of the technique.

Pros

• High strength and durability
• Create a clean and flush joint

Cons

• Require high precision when taking measurements
• Requires additional tools
• Need prior experience for good output

Check out, Biscuit Joint vs Dowel Joint: Which is Better?

5. Using a Pocket-Hole Screw

This method, also known as the Kreg tool technique, is a common and very easy woodworking technique. It is frequently employed in projects like professional building furniture and cabinets.

It involves making pocket holes made with a Kreg jig. 

The screws are kept neatly hidden from view by the angle of the holes.

For this, you’ll need,

• Two boards to be joined
• Pocket-hole jig
• Pocket-hole screws
• Drill
• Screwdriver or drill driver
• Clamps
• Measuring tape

Steps to follow when using a pocket hole screw to join two boards lengthwise,

1. Measure the Collar Depth

Measure the thickness of the wood you need to join and adjust the drilling equipment’s collar to the board’s thickness. The measurement chart of the jig instrument will assist you in drilling holes with exact angles and depths.

2. Mark Pocket-Hole Locations and Drill the Hole

Choose the location for the reinforcing pocket holes and mark them on both boards.

Clamp the board and drill at least two sets of holes for maximum stability.

3. Attach the Joint with Screws

Once drilled all the pockets, using a screwdriver, place pocket-hole screws into the holes and push them into the opposing board until the gap is closed.

The boards will be drawn together by the screws, resulting in a secure junction.

Pros and Cons of Using a Pocket-Hole Screw to Join Two Boards Lengthwise

There are some benefits as well as drawbacks of this technique as below.

Pros

• An easy and quick method
• Create strong joint
• Provide a clean, finished appearance with no visible hardware

Cons

• Requires lot of practice to make a hole laterally
• Not suitable for extremely hard or brittle woods
• Specialized Tools Required
• Limited Aesthetics due to visible holes.

6. Using a Bevel-Cut Scarf Joints

Using a bevel-cut scarf joint, two boards can be joined end to end at an angle to provide a solid and inconspicuous junction. 

When extending the length of the boards, this technique is frequently used.

Tools and materials you’ll need.

• Two boards to be joined
• Circular saw or miter saw
• Clamps
• Wood glue
• Measuring tape or ruler and a pencil

Steps to follow when using a bevel-cut scarf joint to join two boards lengthwise,

1. Mark and Cut the Scarf

Keep two boards with the same thickness on a flat surface and next to each other.

Then, mark the locations where the wood will be cut with a pencil and draw an angled line across the panels.

One board should be cut by setting the miter saw or miter saw blade to a 45-degree angle (or according to your preferred angle) bevel cut and following the line.

Then, cut the other board as well.

2. Apply Glue and Clamp

On one of the boards’ beveled surface, spread wood glue. Make sure they are properly aligned, and connect the two boards at the scarf joint. While the glue cures, secure the junction using clamps.

If you need increased strength, before applying glue, you can add biscuits or dowels to the junction.

Pros and Cons of Using Bevel-Cut Scarf Joints to Join Two Boards Lengthwise

There are some benefits as well as drawbacks of this technique as below.

Pros

• Provide a strong and secure joint
• Efficient in Length Extension
• Virtually invisible if properly finished.

Cons

• Require more time and experience

7. Using Biscuit Joiner

Biscuits like oval-shaped pieces are made from dried and compressed wood like the beech used when creating matching mortises.

For this, you’ll need,

• Two boards to be joined
• Biscuit pieces
• Biscuit joiner
• Wood glue
• Clamps
• A ruler and a pencil

Here are the steps you need to follow when joining two boards lengthwise using biscuit joiner,

1. Identify and Mark Biscuit Locations

Align two boards first. Choose the area you want to emphasize with biscuits and mark them at equal intervals on both boards.

2. Cut the Biscuit Slots

Cut slots in both boards at the marked locations with the biscuit joiner. When the boards are attached, you need to make sure the slots are straight and properly aligned.

Make sure the slot is only half the biscuit’s depth.

3. Insert Biscuits and Assemble the Joint

Now, you need to apply wood glue to the slots and insert biscuits into one of the boards. To activate the adhesive or sealant within the biscuits, mist them with water.

Ensure that the biscuits fit tightly into the slots on the other board before attaching the two boards.

Align and clamp the panel. Until the glue cures, use clamps to hold the boards together.

It’ll take several hours to cure.

Pros and Cons of Using Biscuit Joiner to Join Two Boards Lengthwise

There are some benefits and drawbacks of this method.

Pros

• Creates a strong and precise joint

Cons

• Complex joint
• Need specialized tools and materials
• Less strong and can’t bear lateral pressure for a long period

Let’s look at the next method in which you can join two woods lengthwise.

8. Using Half Lap Joints

Using this technique, identical-sized pieces of wood are bonded by removing the half-thickness of each piece of wood.

For this, you’ll need,

• Two boards to be joined
• Table saw or circular saw
• Measuring tape and ruler
• Clamps
• Wood glue

Here are the steps you need to follow when two boards lengthwise using half lap joint,

1. Mark the Half Lap Location

Choose the location for the half-lap junction on both boards and mark them.

2. Cut the Half Lap Joint

Set the saw blade to half the thickness of the boards, which is the depth at which you want the joint to be.

Create a notch or groove on both boards by cutting along the marked lines. If required, make more passes to obtain the desired depth.

3. Apply Wood Glue on Both Surfaces 

Make sure the two boards are properly aligned before connecting them at the half-lap joint. While the glue cures, secure the junction using clamps.

Pros and Cons of Using Half Lap Joints to Join Two Boards Lengthwise

There are some benefits and drawbacks to this method.

Pros

• Quick and easy
• Provide high strength

Cons

• Must be reinforced with some kind of adhesive

9. Using Tabled Lap Joints

The tabletop lap joint uses glue and two linking portions where the material has been removed to bind two planks of wood together.

You’ll need the following materials.

• Two boards to be joined
• Dado set
• Square
• Table saw or arm saw
• Pencil
• Clamps
• Wood glue

Here are the steps you need to follow when using a tabled lap joint to join two boards,

1. Measure And Mark The Boards

Here, you need to arrange the boards next to one another using the square, making sure that both ends are level. 

Two boards should be marked after measuring the width of the wood piece and adding 1/4 inch.

After that, mark the area where the wood will be cut with an X with the pencil. Draw a line across both boards to join the two ends together.

2. Cut the Dado

Install the dado set in the table saw and adjust the blade height to 1/3 the thickness of the wooden piece and Rabbet on both boards.

After finishing the first set, reduce the dado’s blade height to 2/3 the thickness of the boards.

Make sure the dado blade is perfectly level with the surface of the board. Then, measure half of the wood piece’s width from its shoulder and record the measurement with a pencil.

Clamp both boards, Side-by-side against the miter gauge To determine the width, make two passes around the dado; then, cut the dadoes.

3. Join The Dado Set

Each wooden piece should have its ends trimmed to create a snug fit.

For the wood to thoroughly cure, glue and clamp the parts for at least an hour.

Pros and Cons of Using Tabled Lap Joints to Join Two Boards Lengthwise

There are some benefits and drawbacks of this method.

Pros

• Large wood glue surface and added strength.
• No Visible Hardware

Cons

• Time-Consuming
• Need prior experience

That’s it folks! Now you know how to join two boards lengthwise using the perfect methods.

Now I’m going to share with you some tips that I’ve learned by using the above methods for so long to make your joints stronger and tougher.

Just keep reading to know the experts’ tips important when joining two boards!

Tips for Joining Two Boards Lengthwise

Here are the tips that I recommend you to follow and to get promising results.

• Increase the bonding surface as much as you can. Dowels, bevel-cut scarf joints, and tabled lap joints are a few examples of techniques that expand the bonding surface without changing the site of the bonding.
• To achieve a smooth and stronger joint if you want to employ the strap approach, keep it simple.
• Perform a dry fit to ensure that the two boards are perfectly aligned and that the joint is tight before applying glue. Make any changes that are required.
• Put sturdy dowels in the junction to hold it together. In order to provide additional support for the joint and ensure a strong connection, you can use a wooden or metallic dowel.
• It may require practice to join boards lengthwise effectively. Take your time and don’t rush to get precise, robust, and clean joints.

 So, let’s answer some frequently asked questions.

FAQs

Did I cover all you wanted to know about: How to Join Two Boards Lengthwise

In this article, I’ve deeply discussed how to join two boards lengthwise using proper methods. I’ve described each method in detail with their pros and cons.

The most popular technique of joining two boards lengthwise is edge gluing which you apply wood glue to the edges of two boards, pressing them together, and using clamps to hold them in place while the glue dries. As a result, the junction is made sturdy and flawless. You may use biscuit joints, dowel joints, half-lap joints, etc.

Now you can select the method that suits you the most.

Furthermore, I’ve answered some frequently asked questions as well.

Hope you learned almost all the things you wanted to know regarding how to Join Two Boards Lengthwise. 

Give them a try and practice regularly to become an expert in wood joining happy woodworking!

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