PVA glue – what are the best applications for the different types?
With there being three key types of glue to use, at Multifix, we have decided to highlight the good and not-so-good bits about all of them.
You can see our first glue review here, which is about PU glue. For our second instalment, we’re going to look at the pros and cons of PVA glue.
In this article, we will look at the different types of PVA glue, what they all do and where they are best used.
Polyvinyl acetate, otherwise known as PVA glue, is used for timber bonding, non-structural applications and for general assembly work. This includes things like furniture and laminating timber, while it’s also important to note that it is used with fixings in load critical applications.
There are three types of PVA glue and all of them offer something different. The first is D2, which is general purpose and isn’t designed to be a wood adhesive. Instead, it’s mainly used as a primer or a sealer.
You can use D2 to coat new plaster before painting over the top, for example. Then there is D3, which is your standard waterproof-once-dried PVA glue, which is the most common PVA glue and the one that is most widely used.
Finally, the D4 is PVA with a resin within the formula, making it something of a hybrid glue of sorts. It is stronger and sets faster than D2 and D3.
Whereas PU glue is very messy, PVA glue isn’t. It’s very easy to tidy up and can be cleaned away with water if it spills over anywhere. In addition, if it bleeds through, it dries clear.
Also unlike PU glue, it doesn’t foam up, so it doesn’t need any clamping equipment to hold the workpiece whilst the glue cures, which further adds to the ease of use. In all cases, the bond will be enhanced if clamping is used, but clamping isn’t imperative to the operation.
You also don’t need any applicator guns or other equipment for it, you can just use it straight from the bottle.
If you so desire, you can make it set faster by using controlled radio waves. The radio waves activates the polymers inside the glue and makes it set a lot quicker, which is ideal in production environments where high throughput is required.
The setting times for PVA glue can vary depending on a range of factors, but they can be quite slow, which can be a bit of an issue.
These factors include the temperature of the material and surrounding environment, porosity of the materials being bonded together and the ability for water vapour to escape from the bonded area, amongst others.
It will take at least 10-15 minutes to set, sometimes up to an hour, while it can take 24 hours to fully cure.
In addition, PVA glue has no gap-filling properties and as such, requires clean and smooth surfaces to work properly. For example, if the timber or materials to be bonded together have a rough surface – ie, sawn timber – the PVA will only bond areas that are physically in contact with one another.
This means that in the areas with either no or poor contact, the PVA will dry, but it will have no effect at all on the bond strength.
It’s also very inconvenient to use on cold or wet products and this can slow the setting time even further, while when it comes to bonding, it’s only really for use with timber-to-timber applications.
PVA is primarily a timber-to-timber adhesive. If multiple substrates, such as concrete, brick or plaster are being bonded together, then a PU or hybrid grab/panel would be a better option, especially as some hybrid adhesives can bond to metal and glass.
While PVA glue does have its limitations and can’t be used for a wide range of other materials, when it is used for timber-to-timber, it can really excel.
The fact it’s so easy to use also makes it highly convenient, so when the shoe fits for it, it will be a reliable glue for you.
To find out what glues we have at Multifix or speak to an advisor for what may be best for your project, you can get in contact with us here.
You can see our first glue review here, which is about PU glue. For our second instalment, we’re going to look at the pros and cons of PVA glue.
In this article, we will look at the different types of PVA glue, what they all do and where they are best used.
What exactly is PVA glue?
Polyvinyl acetate, otherwise known as PVA glue, is used for timber bonding, non-structural applications and for general assembly work. This includes things like furniture and laminating timber, while it’s also important to note that it is used with fixings in load critical applications.
There are three types of PVA glue and all of them offer something different. The first is D2, which is general purpose and isn’t designed to be a wood adhesive. Instead, it’s mainly used as a primer or a sealer.
You can use D2 to coat new plaster before painting over the top, for example. Then there is D3, which is your standard waterproof-once-dried PVA glue, which is the most common PVA glue and the one that is most widely used.
Finally, the D4 is PVA with a resin within the formula, making it something of a hybrid glue of sorts. It is stronger and sets faster than D2 and D3.
What are the benefits of using PVA glue?
Whereas PU glue is very messy, PVA glue isn’t. It’s very easy to tidy up and can be cleaned away with water if it spills over anywhere. In addition, if it bleeds through, it dries clear.
Also unlike PU glue, it doesn’t foam up, so it doesn’t need any clamping equipment to hold the workpiece whilst the glue cures, which further adds to the ease of use. In all cases, the bond will be enhanced if clamping is used, but clamping isn’t imperative to the operation.
You also don’t need any applicator guns or other equipment for it, you can just use it straight from the bottle.
If you so desire, you can make it set faster by using controlled radio waves. The radio waves activates the polymers inside the glue and makes it set a lot quicker, which is ideal in production environments where high throughput is required.
What about the negatives?
The setting times for PVA glue can vary depending on a range of factors, but they can be quite slow, which can be a bit of an issue.
These factors include the temperature of the material and surrounding environment, porosity of the materials being bonded together and the ability for water vapour to escape from the bonded area, amongst others.
It will take at least 10-15 minutes to set, sometimes up to an hour, while it can take 24 hours to fully cure.
In addition, PVA glue has no gap-filling properties and as such, requires clean and smooth surfaces to work properly. For example, if the timber or materials to be bonded together have a rough surface – ie, sawn timber – the PVA will only bond areas that are physically in contact with one another.
This means that in the areas with either no or poor contact, the PVA will dry, but it will have no effect at all on the bond strength.
It’s also very inconvenient to use on cold or wet products and this can slow the setting time even further, while when it comes to bonding, it’s only really for use with timber-to-timber applications.
PVA is primarily a timber-to-timber adhesive. If multiple substrates, such as concrete, brick or plaster are being bonded together, then a PU or hybrid grab/panel would be a better option, especially as some hybrid adhesives can bond to metal and glass.
A dream for wood
While PVA glue does have its limitations and can’t be used for a wide range of other materials, when it is used for timber-to-timber, it can really excel.
The fact it’s so easy to use also makes it highly convenient, so when the shoe fits for it, it will be a reliable glue for you.
To find out what glues we have at Multifix or speak to an advisor for what may be best for your project, you can get in contact with us here.