Does Wood Glue Work on Painted Wood?
Wood glue is pretty fantastic stuff.
Whether you’re building an exterior project or repairing a wobbly table leg, there’s no shortage of wood glues that are up for the task.
The downside of this choice, however, is confusion.
Unfortunately, no wood glue is perfect, and you’ll probably need to delve into the technical specs to whittle down the choice based on things like interior or exterior suitability, the drying time, and the finished strength, for example.
Another key consideration, particularly if you’re tackling a furniture repair, is whether or not the wood glue works on painted wood, and that’s what we’ll be answering in this article.
Wood glue does work on painted wood, but it reduces the bond strength versus gluing bare wood. Paint blocks the wood’s pores, stopping the adhesive from penetrating the wood’s fibers (especially in the case of oil-based paints). Most wood glues rely on this porosity to achieve a stronger joint.
Keep reading to learn more about how water-based versus oil-based paints influence paintability and how you can prepare a painted surface to achieve the strongest bond.
Can You Use Wood Glue on Painted Wood?
Wood glue does work on painted wood, but the bond won’t be as strong as a glued joint on bare wood.
The problem is that most types of wood glue, for example, PVA-based glues, are best used on porous surfaces like bare wood. The porosity allows the adhesive to penetrate the wood’s fibers, creating a stronger bond that, in many cases, is stronger than the wood itself.
For wood glues that rely on porosity to increase the joint strength, the ability of the adhesive to penetrate the wood’s fibers is minimized at best or eliminated at worst with the application of paint on the surface.
Other types of glue, for example, two-part epoxy adhesives and polyurethane wood glues, will stick to non-porous surfaces, and so in theory, these will develop a solid bond on painted wood.
The problem here, though, is that the glue’s strength ultimately depends on the paint’s strength and how well it has adhered to the bare wood underneath. Unsurprisingly, this strength is usually much less than is achievable with bare wood.
Don’t just take our word for it, though.
Here’s what Titebond has to say about using their wood glues on painted or finished wood:
Most of our glues are designed to bond bare wood. Painting or staining a wood blocks the pores, keeping the glue from penetrating into the wood. The Titebond Polyurethane Glue may work for gluing together painted or stained surfaces, but it is necessary to remember that the overall bond will only be as strong as the bond between the paint and the wood. We recommend that all substrates be clean of any type of paint, stain, or sealer.
— Titebond
An important point to remember is that it’s called ‘wood glue’ for a reason and not ‘paint glue.’
So, unless there’s no other option, stick to using wood glue on bare wood to increase the strength and longevity of the glue’s bond.
Water-Based Versus Oil-Based Paints
It isn’t as simple as painted versus non-painted wood, though, as the type of paint used will also make a difference in the strength of the glue
For example, water-based paints will seal the wood’s pores to a lesser extent than oil-based paints.
Because of this, glues that rely on penetrating the wood’s fibers, for example, PVA-based adhesives, will have a better chance on water-based paints versus those that are oil-based.
However, while it’s true that the joint will be slightly stronger when used on water-based paint, it’s important to remember that it still won’t be as strong as a joint bonded to bare wood.
What Is the Best Glue for Painted Surfaces?
We specifically mentioned PVA-based and polyurethane wood glues above, but these are just a couple of the available wood glue types.
Here’s a broader summary of the various types of wood glue available and their suitability for use on painted wood:
- PVA Wood Glues
- Aliphatic Resin Wood Glues
- Cyanoacrylate Wood Glues
- Polyurethane Wood Glues
- Epoxy
- Hide Glues
- Hot Glues
PVA wood glues are a modified version of standard PVA craft glue. Both types come from the polyvinyl acetate polymer, but PVA wood glue features several modifications that provide various benefits when it comes to woodworking, for example, a stronger bond and faster setting time.
Check out our article on the benefits of PVA wood glue for more information.
PVA-based glues rely on the wood’s porosity and the ability of the adhesive to penetrate the wood’s fibers to maximize joint strength.
Paint will block the wood’s pores, reducing the strength of the bond versus a joint formed using bare wood.
The bond strength of PVA wood glue is likely to be stronger on water-based paints (when compared to oil-based paints) as these tend to block the wood’s pores less.
Like PVA wood glues, aliphatic resins are another type of modified PVA glue made using the polyvinyl acetate polymer. These glues are sometimes referred to as carpenter’s glues or yellow glues because many varieties dry yellow (although, confusingly, we’ve found that some do dry brown, too).
Check out our article on what color wood glue dries for more information.
Because aliphatic resins are PVA-based, they also rely on the wood’s porosity to maximize a bonded joint’s strength.
You can still apply the glue to painted surfaces, but it will significantly reduce the strength of the joint.
As with general PVA wood glue, the bond strength of an aliphatic resin is likely to be stronger on water-based paints than oil-based paints.
Often referred to as CA glues or instant glues by woodworkers and crazy glue or super glue by DIYers and hobbyists, cyanoacrylate adhesives are well-known for their fast drying times.
They’re often available in a variety of thicknesses, with thicker CA glues being useful for gap filling as well as bonding.
CA glues tend to be most effective on porous surfaces such as those found on bare wood.
You can use CA glues on painted wood, but the overall strength of the joint will rely on the paint being defect-free and how well it adheres to the underlying wood.
As with PVA-based glues, CA glues will likely work better with water-based paints that retain more of the wood’s porosity versus oil-based paints.
You should always check the compatibility of the CA glue with the paint, as some of these adhesives can cause the paint to deteriorate and break down.
Polyurethane glues are usually multi-purpose, sticking everything from wood to metal. One of the biggest benefits of polyurethane glues is that most varieties are waterproof, making them ideal for outdoor projects.
As mentioned above, polyurethane glues will stick to both porous and non-porous surfaces, and so, in theory, these will develop a solid bond on painted wood.
Because porosity isn’t a critical factor, you can use polyurethane wood glue with water-based and oil-based paints.
Doing so will lead to the same problem as with the other types of wood glue, though, in that the glue’s strength will ultimately depend on the paint’s strength and how well it has adhered to the bare wood underneath. Unsurprisingly, this strength is usually much less than is achievable with unpainted wood.
Several different types of epoxies are available, but the most popular types are two-part, consisting of a hardener and a resin mix. Epoxies can be used to bond various materials, not just wood, and they have excellent chemical and water resistance that makes them a good option for outdoor applications.
Two-part epoxy glues will work on both porous non-porous surfaces, and so you can use these with both water-based or oil-based paints.
It’s worth mentioning that on oil-based paints, or any non-porous surface, two-part epoxies adhere better when the surface is roughened or ‘keyed’ slightly by sanding.
Doing so won’t increase the joint’s strength to the level achievable with bare wood, but it should still help.
Unlike most glues on the market, which are chemical-based, hide glue is a natural type of wood glue typically made from the bones or hide of cattle. Because of this, hide glues are non-toxic while still providing a reasonable degree of water and chemical resistance.
Hide glues rely on the wood’s porosity and the ability of the adhesive to penetrate the wood’s fibers to maximize joint strength.
The bond strength of hide glue is likely to be stronger on water-based paints (when compared to oil-based paints) as these tend to block the wood’s pores less.
Hot glues, or hot melt adhesives, come in a stick that melts when pushed through the nozzle of a hot glue gun. A significant disadvantage of hot glue is its poor heat resistance, which causes it to return to liquid form when reheated. Because of this, they’re probably better-suited to hobbyists than woodworkers.
Commonly used for craft projects, hot glue works best with porous materials like bare wood or cardboard.
You’ll fare better using hot glue with water-based paints that retain some of the wood’s porosity versus oil-based paints, which tend to seal the pores.
PVA wood glues, aliphatic resins, CA glues, hide glues, and hot glues rely on a certain amount of porosity to increase the strength of the joint. These types of glue will fare better on water-based paints that retain more of the wood’s porosity than oil-based paints.
Polyurethane glues and two-part epoxies should work on both water-based and oil-based paints, as they can stick to either porous or non-porous surfaces. For both types, we’d recommend roughening or ‘keying’ the paint’s surface via sanding to improve the adhesion of the glue, especially when bonding to an oil-based paint.
At the risk of repeating ourselves, though, none of these bonds will be as strong as if you were to apply the glue to bare wood.
Can You Paint Wood Before Gluing?
Depending on what you’re building, sometimes it makes more sense to paint the wood before assembly.
Thankfully, this is very simple to achieve, and all you need is a bit of planning and some masking tape.
Apply Tape to the Area of Any Joints
Once you’ve got the wood required for your project, the first step is to mark where any glued joints will be and to cover these with painters or masking tape.
If you’re working with water-based paint, we’d recommend using a specific ‘no bleed’ tape to ensure the paint doesn’t work its way underneath during the next step.
Paint the Wood
Once you’ve covered the location of any glue joints with tape, you can go ahead and paint the wood.
If you plan on applying multiple coats, it can be a good idea to remove the tape between each coat. You can then sand the piece thoroughly before using more tape for the next coat of paint.
Remove the Tape
Once the paint is dry, you can go ahead and remove the tape to expose the bare glue area.
Apply Glue and Clamp the Joint
Go ahead and apply glue to the unpainted areas of the wood.
Finally, clamp the joint and allow it to dry as per the glue manufacturer’s guidelines.
How Do You Remove Paint From Wood Before Gluing?
From repairing furniture to various DIY odd jobs, there will likely be situations where you need to bond already-painted wood.
In some situations, you might choose to apply glue directly to the paint itself. However, as discussed above, this will significantly reduce the strength of the joint, and so this will only be suitable where the glue won’t be stressed, for example, through excessive movement or where weight is applied.
Where a bit more strength is needed, though, it’s typically best practice to remove the paint from the areas where you’ll be applying glue.
There are several ways to do this, which we’ll touch on in a moment. Although it can seem a bit dull, it’s probably worth mentioning a bit about health and safety before you get stuck in stripping paint.
Firstly, it’s a good idea to check for lead paint, which is particularly nasty stuff that is relatively common in older houses. You can pick up a lead testing kit relatively cheaply, but it’s worth getting specialist guidance on how to remove lead paint if you come across it.
We’d also highly recommend putting on some protective equipment, too, including gloves and goggle at a minimum, as well as a respirator if dealing with any chemical paint strippers.
Now that’s out of the way, here are a few ways to remove paint from wood ahead of gluing:
- Using a chemical paint stripper – Usually, the fastest way to remove paint, chemical paint strippers tend to be very aggressive and can easily remove multiple layers or the most stubborn of paints. They can be particularly nasty to your health, though, so make sure you wear protective equipment.
- Using a natural paint stripper – These likely won’t be as effective as a chemical paint stripper, but they’re non-toxic, environmentally friendly, and generally much more pleasant to work with.
- Using a paint scraper – You can use a scraper by itself to scrape away the paint. Using a chemical or natural paint stripper at the same time will make the job much easier, though.
- Using coarse sandpaper or a sander – Probably the slowest way to remove paint, but it can be ideal for small areas. A powered sander will speed up the process, but this can make it challenging to access tight spots or corners, so you’ll probably need to follow up with some manual sanding using sandpaper, too. Watch out for paint dust and wear protective equipment.
- Using a heat gun – A good way to loosen stubborn paint, heat guns can be handy when used with a scraper. Watch out for any potential fire risk, though, and be careful not to damage the underlying wood by applying too much heat.
Related Questions
Does Titebond Work on Painted Wood?
Titebond is a brand name, and there are plenty of Titebond-branded wood glues available.
It’s worth mentioning that Titebond’s manufacturer, Franklin International, advises explicitly against using their wood glues on top of paint or other wood finishes.
Although not recommended, Titebond wood glue does work on painted wood, although it will likely significantly reduce the bond strength.
PVA-based or aliphatic resin glues such as Titebond Original, Titebond 2, and Titebond 3 rely on the wood’s porosity. They will probably work better with water-based paints that don’t block the pores to the same extent as oil-based paints.
For oil-based paints specifically, Titebond Polyurethane Liquid Glue is probably a better option, provided the paint is roughened to aid adhesion (although the joint will still be weaker than gluing bare wood).
The same principles apply for Gorilla Glue and Elmer’s Glue, too.
Does Construction Adhesive Work on Painted Wood?
You can use construction adhesive to bond painted wood.
As with the other types of wood glue mentioned in this article, though, you’ll ultimately be bonding to paint itself, not the underlying wood.
Because of this, any defects in the paint, for example, cracking or brittleness that is typical in older finishes, will significantly reduce the strength of the joint.
Scraping the painted surface back to bare wood is probably the best option to maximize the construction adhesive’s strength.
Does Hot Glue Work on Painted Wood?
Hot glue can be used on painted wood, although a downside to painted timber is that it’s much less porous.
Water-based paints will seal the wood’s bores to a lesser extent than oil-based paints, so the bond strength is likely to be higher when using the glue on a water-based paint.
Hot glue works better where the porosity is high, as it gives the adhesive something to grip.
Where bond strength is critical to your project, we’d probably advise using a different type of wood glue, such as a PVA or polyurethane alternative, as hot glue isn’t very strong.
If hot glue is all you have to hand, you should at least scrape the paint back to bare wood following the steps above to improve bond strength.
Final Remarks
While wood glue work on painted wood, there are a few reasons why applying wood glue to painted wood generally isn’t a good idea:
- Paint significantly reduces the porosity of the wood, meaning the glue cannot penetrate the wood’s fibers (especially in the case of oil-based paints, as mentioned above). Some wood glues, for example, PVA-based varieties, rely on this porosity to achieve a stronger joint.
- The glue’s strength ends up depending on the strength of the paint and how well it adheres to the wood. Any defects or issues in the paint, such as cracking or brittleness, which are common as paint ages, will cause the glue joint to fail much quicker under less load than gluing bare wood.
- Some CA glues (i.e., super glues) can break down the paint, simultaneously deteriorating the finish and reducing the strength of the glued joint.
So, unless there’s no other option, stick to using wood glue on bare wood to increase the strength and longevity of the glue’s bond.
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