Beginner CA Glue Problems and Solutions Explained Here - Part I

cyanoacrylate glue

Originally, CA glues were meant to be used in small amounts. Cyanoacrylate glues actually and perceivably perform better when less are applied. When less glue is used, the instant adhesive dries faster, allowing it to reach its full bonding strength sooner.

Before blaming the adhesive, there are 3 instances when CA glues seem to have poor performance:

Is Your Glue Drying Slow?

The normal suggested drying time of CA glues (i.e. the dry time of Thin CA glue is 2-3 seconds) are based on 1 drop per square inch applications. When filling cracks, cavities, gaps, and voids with CA glue, larger volumes of adhesive may be required to fill the empty space. larger volumes of CA glue may be used to fill the empty space. In such case, it can take minutes to hours for the cyanoacrylate glue to fully dry.

Are the Surfaces Not Bonding?

Clean the surface contaminants. Dirt and oils may have unexpected reactions with the glue — at times, resulting in a white residue on the surface or a weaker bond integrity.

When the surface to be bonded is very hard or smooth, it will require more time and effort for the ca glue to bond. The technical reason for this is that hard, smooth surfaces have "low surface energy". In contrast, surfaces that are soft and porous require less time and effort for the ca glue to bond. This is because these types of surfaces have "high surface energy". Here's how I make sense of this. Imagine two puddles of water: one on a marble floor and another on a concrete floor. The water will evaporate faster off of a concrete floor than a nicely polished marble floor.

Cold Temperature

In colder temperature, the drying time of CA glues will be significantly delayed. Keep this in mind during the colder seasons. In addition, if you store your glues in a refrigerator or a freezer (which is highly recommended to prolong the shelf life of CA glues), let the glue warm up to room temperature before using.

Bonus Tip: At times, the cold temperature is something you can use to your advantage. If you plan to stabilize a deep cavity or a porous object with thin CA and want to ensure that the CA glue reaches the bottom before it sets up, use the glue straight out of the refrigerator or a freezer before it reaches room temperature. This should buy you some extra time.

Solution

Using a CA accelerator, also known as CA activator, works wonders in accelerating the drying time of the CA glue. Most accelerators contain acetone as its evaporating agent, so if you think it could be too harsh for the surface you're working on, it's recommended to spot test first. Not only does the Accelerator speed up the drying time of the glue, the acetone also works to prime the surface through the removal of contaminants. Typically, one brand of accelerator can be used on another brand of CA glue.