To be strong, the dowel joint needs adhesive

Joining with dowels - tipli or cepi/ceps as these small serrated wooden cylinders are also called - is one of the most commonly used methods of joining elements of a piece of furniture. Whether it's wooden, chipboard or MDF furniture, dowels help to form a solid bond between the elements, helping to stiffen the body. If wooden furniture is preferred for jointsswallowtail or log and hollow, being more aesthetically pleasing and more durable, the dowel joint is a winner for chipboard or MDF furniture. Regardless of the type of furniture, if we relate the simplicity and aesthetics of the joint to its strength, the dowel joint will be the winner. Provided it is a non-detachable one, i.e. adhesive is used to make it.

What are the advantages and disadvantages of dowel jointing

Even if classic carpenters consider it a trivial and not very resistant joint, and modern ones go for those with screws or sophisticated systems, the dowel joint has a number of advantages that cannot be ignored. Here are some of them:

• It is simple to do and does not require complicated equipment. A drill, a suitable drill bit, dowels and wood glue is all you need.
• It can be used in DIY projects, even by beginners, to repair wooden household items.
• Very aesthetic joints can be achieved without much effort. In this case, the joint must be visible and the dowels used must be made of a wood of a contrasting colour to that used for the rest of the furniture.
• It's a durable enough joint you can rely on. Increasing the number of dowels increases the strength of the joint, provided they are correctly placed.
• Helps strengthen and stiffen furniture casings alongside other fastening systems.
• It is very suitable for putting pieces together at a 90º angle or in extension.

Of course, there are drawbacks:

• It is weaker compared to the log-and-notch joint, widely used in the manufacture of wooden furniture.
• If certain requirements are not met - for example, the diameter of the hole must be less than half the thickness of the piece of furniture - this results in imperfect and less strong joints.
• If the dowels are not chosen correctly or the wrong adhesive is used, the joint may fail over time.
• Variation in air humidity can lead to dimensional shrinkage of the dowels and the appearance of joint play.

Regardless of the pros and cons, dowel joints continue to be widely used in furniture making. Detailed information on this type of joint can be found athere.

What kind of glue to use and what dowels to use to make the joint as strong as possible

The adhesive used to fix the dowels must have a fast setting, short setting time, be consistent without excess filler and be suitable for future use of the object. That is, if it is used to join garden furniture or furniture used in areas with high humidity, the adhesive must be D3 or D4. Otherwise, the adhesive will fail over time and at the first mechanical action, the joint will come apart. The most commonly used adhesive for such joints is aracite type, i.e. PVA (polyvinyl acetate). If done correctly and the adhesive is chosen properly, the joint will be very strong, yielding to mechanical action in wood or chipboard.

The edges must be curled to make room for the adhesive and to ensure as large a contact area as possible. They must be similar in diameter to the hole so that there is no play, but also so that they cannot get in. The hole should be slightly longer than the dowel so that the dowel fits all the way in and the pieces fit together perfectly. There must also be room on the inside for the adhesive film. The dowel is checked without adhesive after the hole is made to see if it fits. Excess adhesive is then applied and the dowel is forced into the hole by tapping it with a hammer, preferably wooden. This prevents damage to the parts. Excess adhesive that comes out is wiped off with a wet cloth. At this stage it is very easy to clean. After curing you will need to use a metal scraper to remove the film that has formed.

Special adhesive for dowel joints

For such joints consumption seems small and unimportant, but it is not. The proof is that companies have dedicated products for such joints. One example is the adhesive TISZABOND 2300 the firm's Szolvegy specially designed for dowel joints. It is a PVA adhesive with reactive groups and a high dry matter content that has a fast tack with short pressing time. The adhesive is specially formulated for dowel jointing of furniture that does not sit in high humidity environments, i.e. it is a D2 adhesive. The low moisture resistance requirements make the adhesive an economical adhesive, its mechanical strength remains very good. However, if you want a bond with very good moisture resistance (outdoor conditions) you will have to turn to the adhesives TISZABOND D4, mono or bi-components, depending on the strength requirements.

If you're a DIY enthusiast, dowel-jointing is a good choice for making or repairing various objects, both from a strength and aesthetic point of view. To make sure you don't make mistakes when drilling holes, you can use special putties that make dowel-jointing child's play. Good luck!