One of the most common questions that I get asked is “what do I use to stick my mouldings to my project?” There are a lot of different glues out there, and though a post was made previously about this subject, I decided it was time to update it and add a few more options.

Before doing a comparison I just want to point out that there is one huge factor that will affect the sticking of your mouldings: The back of the moulding must be nice and flat. When a moulding is first de-moulded, it is often slightly concave on the back. I sand the backs of all my mouldings on an industrial belt sander to ensure that the backs are nice and flat. I then refine the edges, sanding by hand, to ensure a nice finish all around. Most of my competitors do not bother to do this. This has a big effect on the ability to glue the moulding to a flat surface as a slight recess or a shiny smooth back will inhibit the glue’s performance dramatically.

 

Contender # 1 – Construction Adhesive

This is one of the common choices by many to apply their mouldings. There’s no denying it has quite a grip

What I like about it:

  • This is an easy solution for a really strong bond to most surfaces.
  • It is very affordable and can be bought in cartridges which gives you much more product for not much more money.
  • It is widely available. All DIY stores should stock it.
  • It sets reasonably quickly.
  • It’s commonly used and may be something that you may already have lurking in the shed if you’re a keen DIYer.
  • Some brands offer a “quick grip” option – great if you are adding your mouldings to a vertical surface, and you don’t need a clamp as the glue grips quickly and holds strong until it cures.

What I don’t really like about it:

  • You will need a caulking gun. A good caulking gun (which can apply high pressure with little effort) is a necessity for the higher quality quick grip glues as they are very viscous , therefore difficult to press out. Regular construction adhesives such as no more nails will work just fine with a cheap caulking gun form your Local DIY store.
  • I do generally find this a bit clumsy to use. It’s usually supplied in a large tube to be applied with a mastic gun. This can be a little tricky to do with a degree of accuracy, which you will need for smaller mouldings. You can dispense a bit of glue out and apply with a spatula, but you need to work fast as a dry skin will form on the glue where it hits the air.
  • As the adhesive is quite thick it has a tendency to hold the mouldings off just a little which can leave a bit of a gap around the edges of your mouldings. Less is more.
  • It is solvent based, so can be odorous in an enclosed space. If you’re using it indoors it can leave a bit of a chemical odour which some may object to, especially if you have a lot of items to stick.
  • Lastly I also found that (unless it is a quick grip type) it takes a little time to cure the mouldings. They therefore have to be held in place so that they don’t sag or drop out of place before they are set.

 

Contender # 2 – PVA (Wood Glue)

PVA (Poly Vinyl Acetate is a water based glue that is budget friendly and easy to apply. It provides strong adhesion as long as teh surfaces are properly prepped. It can stick a wide range of materials,

What I like about it:

  • PVA (Poly Vinyl Acetate is easy to apply to even the smaller mouldings with a good degree of accuracy – you can use a squeezy bottle or even a paint brush to put it exacltt where it’s needed.
  • It dries reasonably quickly for a water based product.
  • It has a very low odour and no protective gear is needed, so it an be used in the house.
  • It cleans up easily with water if you have a mishap.
  • It has a low initial grab but once it sets the bond is extremely strong.
  • It’s cheap and widely available.

What I don’t really like about it:

  • Lack of initial grab to hold the moulding in place, and so it seems a little ‘greasy’ (if that’s the right word!) and as you press on your mouldings they tend to slide around a little until you have secured them into place while the glue sets.
  • As PVA is quite runny you also have to be careful not to use too much as it can have a tendency to run or drip a bit which can lead to a little extra work.

 

Contender # 3 – Gorilla Glue

This glue is a little like PVA in that is is a popular wood glue, but it has a foaming property – that is, it expands a little to fill gaps. Whilst it’s ability to expand is extremely useful when gluing between items that may have gaps that would benefit from a fill, it can invite a bit of extra work.

What I like about it:

  • See reasons for PVA Glue above.
  • If fills small gaps nicely.

What I don’t really like about it:

  • See reasons for PVA GLue above.
  • You will need to use a strong clamp. This is because as the glue expands, it will add bulk between the surface you are gluing to and the moulding. Too much glue underneath can cause the moulding to sit proud, creating a gap around the edge. Since it’s an expanding product, it can also expand to ooze out from the edges, so be aware you may need to wipe it up before it cures, or sand it away afterwards. It’s best if your mouldings are adhered in such a way as to minimise this, and a clamp will ensure a close fit.

If you are painting your moulding after gluing, this is less of a problem because you can fill any gaps once the glue has cured. Once it’s painted, no-one will know there was a gap there. It’s an extra step of work to consider, though.

 

Contender # 4 – Hot Glue Gun

This is an easy to use solution that many people seem to like.

What I like about it:

  • This is a convenient adhesive that can bond many different materials. It’s quick with a good instant grab and as soon as the glue is cooled, it has set, usually within a minute or so.
  • There’s not really any clean-up to worry about as the glue cures so quickly,.
  • There’s generally no need to support the mouldings in place until the glue has set.

What I don’t really like about it:

  • Hot glue is, well…hot! Get it on your fingers and you’re going to know all about it. Make no mistake, you will burn yourself while using this.  Keep a cold bowl of water handy to plunge your fingers into just in case.
  • The gun has to heat up enough to almost turn the glue to a liquid in order to be useful and this can take some time, as well as being dependent on being close to a power socket, not ideal in all cases so something to bear in mind.
  • When you pull a glue gun away, it can create fine strands of glue that you just don’t seem able to get rid of. They can get everywhere – it’s like you’ve had a duel with Spiderman! So after you’ve attached your mouldings you will likely have sore fingers and strands of glue all over you, not to mention the glue is thick and leaves a gap around the moulding as a result. The bond is also not the strongest and mouldings can be knocked off with little effort
  • In addition, you need to work fast with hot glue. It can otherwise cool and harden enough to remain a bit bulky behind the moulding.

Always use a very high quality glue, and make sure both surfaces to be glued together are a little rough, or you are likely to find a moulding has popped off at some point.

 

Contender # 5 – Mitre Adhesive Kit

Our go-to glue for mouldings is a 2 part Cyanoacrylate glue kit. This consists of a glue and an accelerator. It’s the Mohammed Ali of glues!

What I like about it:

  • This glue offers a strong bond and cures fast. So the first part is just like super glue, but it comes with a second part, an activator which when combined sets the glue in seconds and it’s hard as granite! Only a small amount is needed and it will allow you to stick lots of mouldings is a very short space of time.
  • There’s no need to secure your mouldings in place with tape etc as with the other glues as it sets so quickly and you will find 101 uses for it around the home as well.

What I don”t really like about it:

  • Well, not much actually, it’s pretty much the ideal glue for the job. The only thing to note is that it’s not great on something like Annie Sloan Chalk Paint™ if it hasn’t been sealed. It seems like it reacts and lifts the paint off. Once the paint has been sealed though, the glue is fine. As 99% of the time you will apply your mouldings before you paint, this is a major problem.
  • You’ll need to be pretty accurate with positioning your mouldings once you have applied this glue  as is sets very quickly, oh and it’s also a good idea to wear some protective gloves as if you get this glue on your fingers it’s going to be there for a while!
  • It’s pretty easy to accidentally glue yourself to your moulding, the workbench, yourself etc etc, so be sure to get some un-cure if it’s available for your brand of glue.
  • It’s not the cheapest option but a little does go a long way.
  • It can make your eyes water if you are sensitive to it, and the activator can be a bit smelly.

Contender # 6 – Cyanoacrylate Glue (Super Glue)

If you cannot find a 2-part cyanoacrylate system easily, a regular superglue will do – you will need to hold it in position firmly until the glue is cured. I recommend having some un-cure around just in case – believe me, I have stuck my fingers to themselves, to the project I’m working on, and to tools I am using when the glue runs unexpectedly, and un-cure has always got me unstuck. I recommend using a gel or thicker cyanoacrylate glue rather than a thin runny one as it’s easier to control.

I absolutely recommend Insta-cure (pictured ) or maxi-cure as they are great quality, you can get extra nozzles, they come in various sizes and they have an un-cure and kicker (activator) in the same branding. It’s also a great price.

What I like about it:

  • Just like the Mitre Bond, this adhesive offers a strong bond and even without an activator, is relatively fast curing. You can get accelerators for some brands of superglue, and it’s very handy having some around to speed things up when needs be.
  • Again, only a small amount is required.
  • It cures relatively quickly so it’s not the end of the world if you need to press your mouldings in place while it cures.
  • Small nozzle means you van be accurate with glue application.
  • You can get a flexible cyanoacrylate glue – suitable for gluing  flexible mouldings onto flexible surfaces.

What I don”t really like about it:

  • The same dislikes as for Mitre Bond (above)
  • A very runny superglue can make a mess.
  • The nozzle can get clogged. Some brands offer replacement nozzles If you are using cyanoacrylate glue a lot, I recommend getting a few to fit your favourite brand.

 

Contender # 7 -Two Part Epoxy Glue

Examples of this type of glue are Araldite, but you can get other brands and they are all very similar.

What I like about it:

  • You can get this glue in different cure times. The longer the cure time, the stronger the glue (as a general rule of thumb) but the 5-minute cure is absolutely adequate and nice and quick to cure, especially in a warm environment.
  • It offers great adhesion.
  • Reasonably priced if you don’t buy it in the very small syringe packs.

What I don”t really like about it:

  • It can be messy, It pays to mask off the area around the moulding first, especially if you are putting a pre-painted moulding onto a different colour or unpainted surface.
  • Smells faintly like rotten fish until cured.
  • This glue is clear, but it does have a tendency to yellow. It is unlikely to be a problem in this scenario, though.

 

Contender # 8 – Silicon Adhesive

This is one of the common choices by many to apply their mouldings. There’s no denying it has quite a grip

What I like about it…

  • It can be bought in cartridges which gives you much more product for not much more money.
  • It is widely available. All DIY stores should stock it.
  • It is flexible an therefore suitable for applying flexible mouldings to flexible surfaces.

What I don’t really like about it…

  • You can get it in small tubes (not caulking gun required), but they are pricier. For the cartridges, you will need a regular caulking gun.
  • As with construction adhesive, a caulking gun can be a bit messy to use.
  • Can cause bulk behind the mouldings, so less is more.
  • Messy to use – if some oozes out from behind the moulding, it can be a nuisance to clean up. Again, less is more.
  • Mouldings applied using this adhesive will also need to be held in place while the adhesive dries.

Contender # 9 – Contact Adhesive

This is a solvent based, thin glue. It can be sprayed or brushed on, and there are many strengths and brands available. It is a flexible glue, so is great for adhering flexible mouldings to flexible surfaces. The colour is generally a honey brown, though some are white.

I tend to prefer the type that is sold a  cobblers glue (sometimes known as barge) that can be reactivated by heat. I have also found the neoprene glue works well, and it is quite widely available at DIY stores now, so may be an easier option to get hold of.

This type of glue works a little differently to most in that you must apply glue to both of the surfaces. All surfaces need to be keyed (roughened up) and clean. It helps to “prime” each surface with a thin layer of glue first and let it completely dry to create a really good surface. Next, apply a second thin coat of the glue. Wait until it is not quite dry, but just slightly tacky.

What I like about it…

  • It is flexible
  • It grips instantly – no clamps needed, or waiting time to dry once the mouldings are on,
  • Contact adhesives that can be reactivated by heat are forgiving. With unpainted mouldings, if you apply the moulding incorrectly, you can heat up the moulding with a heat gun. The glue will become gummy, allowing you to remove it.
  • It is inexpensive.

What I don’t really like about it…

  • Contact Adhesive is solvent based and therefore toxic and extremely odorous. You must use it in a very well ventilated space and use a respirator.
  • It is runny, so can be messy to apply. I like to decant some into a squeezy bottle and wedge of closed cell foam (EVA or plastizote) to spread it around. A spatula also works fine, an you an use a paintbrush to paint glue onto the area that the moulding is being adhered to if you need more precision.
  • Smooth surfaces will not like this glue. Careful preparation is needed because this glue bonds best to rough surfaces.
  • You will need to mark the area within which the glue will sit to avoid painting glue onto areas that will show. This is less of a problem if you will be painting the piece afterwards, but it’s best not to apply glue where its not needed.
  •  If you accidentally apply it wonkily, and are using a pre-painted moulding, using a heat gun to reactivate the glue will cause the paint to bubble.

Pro tip – Deacant into a squeezy bottle for better application control. Don’t forget to label what is in the bottle!

 

And that’s it! My definitive guide to adhesives and how to use them with your decorative mouldings projects. If you have any queries, drop a comment below or email me. And please post a comment below to let me know which glue you’ve tried and how you found using it. Remember to share and like on Facebook too, your likes and comments are always appreciated.