If you have ever worked with wood, say a toy, or furniture, you would have wondered just how long the glue takes to dry.
If crafts are what you do, you will be asking this question seriously, because as a dedicated woodworker, it would matter if your intention is to create long-lasting objects.
We will look at this simple-sounding question objectively and look at aspects that may affect some of the things that have a role in the drying abilities of glue.
The bottle which you use to dispense the glue may have instructions that indicate that the glue takes a certain number of hours to dry, but does it also tell you when to take the clamps off?
Aspects That Affect the Drying of Glue
As mentioned above, there can be many numbers of factors that may affect the drying time of the glue. While a number of facts can be presided over, others should be taken into consideration. Sometimes, it could be the wood itself.
What Type Is Your Glue?
There are a large number of glue types, some of which are epoxy, casein, polyurethane, animal glue and they all have their own properties, applications and drying time.
Some glues have a very short period of drying time (as you may have seen in countless advertisements in print and TV), others take longer, depending on what they are being used for, in this case, big chunks of wood.
The most common type of quick-drying glue used for common household jobs is polyvinyl resin. This is perfect for jobs that are not bound to be exposed to high heat or extreme weather and needs waterproofing.
For woodworking, animal glue, or hide glue (so called because it is collected from boiling animal connective tissue) is used and has a higher setting time.
Glues and Their Setting Times
These types of glues are otherwise known as superglues and quick-drying glues, so naturally, they have quick curing (a process that will turn the liquid glue into solid) and setting time.
A typical superglue will set in about 5-60 seconds and will cure in about a couple of hours. These glues work best for wood, plastic and metal.
This glue is typically used to construct plastic models. They set in less than a minute and will cure in as many as 8 hours.
These glues are best used for plastic because they actually dissolve the layer of plastic they are applied on and fuse it to the adjoining piece.
Epoxy is the most commonly-used glue and has been in use for a very long time. It is waterproof and shrink resistant and also fuel proof.
The setting time is about 5-30 minutes and they fully cure in about 12 hours. These glues work on wood, fiberglass, glass, paper, plastic and metal.
This type of glue can be applied on to flexible surfaces because it uses natural rubber as a base. This type of glue works on all types of surfaces and take about 12 hours for setting and up to 2 days to fully cure.
Also known as ‘white glue’, this is the glue that you see children use in arts and crafts projects. They can be cleaned and thinned with water and become quite strong after drying.
They work on wood, paper, plaster and foam and not so great on metals, rubber and plastics. These glues take up from 15 minutes to an hour and cure completely in about a day.
The density of the Wood
To join two pieces of wood, some part of the glue needs to remain on the surface, while some, needs to wet it. The more porous the wood, the more glue it will require because some of it will be absorbed by the wood.
To create a tough bond between the two pieces, some glue will remain between them. This would mean that the denser the wood, the lesser the glue it will require and hence the setting time would be shorter.
This is because there would hardly be any moisture to escape so that the glue can be set.
Please note that the more glue the wood absorbs (if it is porous), the stronger the bond will be. In other words, the more the glue penetrates the wood’s surface, the better the bond will turn out to be.
If the environment has a lot of humidity, it would take longer for the glue to form a bond, because the moisture in the glue also needs to evaporate.
Having said that, if the wood has been stored in a moist environment, it would also take some time for the moisture absorbed by the wood to evaporate.
For this reason, any woodworker will tell you that the wood needs to be well cured in order for it to retain a bond. You may have often seen woodwork being done in areas where the moisture content is low, such as outdoors or in sunlight.
Similarly, pieces of wood which have natural moisture will take a longer period to dry, because it will take time for that moisture to evaporate via environmental factors.
We saw that excessive moisture will cause the glue to dry slower. Following that logic, the higher the heat, the quicker the glue will dry and set.
This also depends on the purpose of your craft. Sometimes, resins like polyvinyl could melt because of very high heat, causing the bond to soften.
Other times, areas which are hot, but retain moisture (coastal areas), they will cause the glue to dry slower.
As we saw, there are multiple factors that can affect the length of time taken for glue on wood to dry. While making a bond between pieces of wood, it must be kept in mind that all these factors come into play.
It could be the environment or the kind of glue you are using or simply the type of wood. Whenever you are buying glue for your project, pay close attention to the instructions that are provided at the back of the bottle.
Some glues are quick to bond but may have a longer curing time.