How To Glue MDF Boards Together: DIY Methods That Work

Whether doing a small DIY project or building larger furniture, gluing is a major part of woodworking. If you are a carpenter, you know well that gluing wood and fiberboards is a bit tricky, and it is not just about pouring glue and joining pieces of wood together. You must follow good techniques and use the best glue and other materials to get a strong, long-lasting bond.

This article will find out the straightforward process of how to glue MDF together.

Keep reading to learn:

• What is MDF
• Types of MDF
• How to glue MDF together
• How to glue MDF edge
• How to hide MDF edges

What is MDF

MDF means medium-density fiberboard. As the name suggests, it’s a particular wood product created from softwood or hardwood residuals. The process includes a thermomechanical pulping refiner, or Defibrator, where wood residuals are turned into wood fibers and panels using wax and resin binder. Usually, the whole process is done under high temperatures and pressure to make this kind of fiberboard.

Types of MDF 

MDF, or engineered wood, is better, more durable, and denser than plywood. Generally, there are three kinds of medium-density fiberboard based on their specific characteristics:

• Moisture resistant MDF
• Fire retardant MDF
• Ultralight MDF

1. Moisture-resistant MDF: Moisture-resistant MDF is created by a moisture repellent resin which safeguards the panel from moisture or humidity. These fiberboards are popular for window boards, kitchen and bathroom furniture, architectural moldings, skirting and architraves, flooring, and general interior joinery. To make moisture-resistant MDF more useful, you can apply moisture-resistant paint on the outside layer.
2. Fire retardant MDF: This fiberboard is made with the help of phenol-formaldehyde resin, which acts as a heat barrier. Fire retardant MDF is made from wood fibers mixed with resin and waxes and finally hot-pressed to its desired thickness.
3. Ultralight MDF: Ultralight MDF weighs approximately 30 percent less than standard MDF. This fiberboard is produced from a pine tree called Radiata pine, creating a flawless surface. Though the materials in ultra-light MDF are the same as in full-size MDF, they are a bit weaker due to their size.

Which Glue Works Best in Attaching MDFs Together

Any wood glue or PVA glue will work great to fix MDF. However, use an all-purpose glue or plastic resin for a trustworthy result.

How to Glue MDF Together

Gluing MDF together is a straightforward process; you can do it yourself with a little patience. Sometimes you will need to make the bond between MDF sheets as well as join them with other materials like veneer, plywood, glass, metal, etc. However, like any other process, collect the necessary tools and materials for a smooth process.

Required Materials

• All-purpose Epoxy or plastic resin
• MDF boards
• Hand gloves
• Spline joints
• Clamps
• Screw

After managing the items mentioned above, you can start the adhering process. Follow the steps mentioned below to have a smooth gluing process and strong bonding between MDF boards.

Make a spline joint

A spline is a slat of MDF or wood, and a spline joint is created when two pieces of MDF are connected edge to edge or end to end. This is secured with the help of a spline inserted in the slot on two edges or two ends of the pieces of wood or boards. To make spline, you must avoid softwoods, and if possible, you should go for dense woods. For example, walnut or hard maple is suitable for this purpose.

• Measure the length and breadth of both the boards’ edges or ends.
• Take the spline and use a pencil to draw an equal division. Nowadays, machines like a router or biscuit joiner are good enough to decide the middle point of the spline joint.
• Use a router to create a slot at the edge of the boards.
• Insert the spline into the slot and check whether it fits smoothly or not.

Use glue

Now it is time to use glue and the next steps.

• Take the spline off the slots, and apply glue.
• Insert the spline into place, and attach both the ends or edges of the boards.
• Let the glue dry.
• During drying, use clamps; they are suitable for holding both the pieces until the glue dries. You can also use tape if the MDF boards are tiny in size.
• Finally, you can see the best result if you let the glue dry for 24 hours. It can be a bit less, but the time will more or less be the same.

How to Glue MDF Edge

If you want to glue the MDF edge, you must create bigger spline joints, requiring more glue. Just make a slot on the edges of both MDF boards, insert the spline, and glue both the boards.

How to Hide MDF edges

A thin line can be seen if you glue two MDF boards on top of one another. Most of the time, these lines look ugly, and hence they should be removed. To do so:

1. Take wood filler, filling knives, sandpaper, and wood primer undercoat.
2. First, apply wood filler on the edges with the help of knives and make it smooth with sandpaper when it dries.
3. In the end, use a wood primer undercoat.

Frequently Asked Questions

Final Words 

Gluing is a part of craftsmanship. MDF boards can be made into helpful furniture if the proper technique is applied. We hope you have got ideas about how to glue MDF boards together.