It looks like wood, it smells like wood, it feels like wood… but does it GLUE like wood? MDF can be hard to work with. In this article, we’re looking at the best glues for your MDF projects.
In a rush?
No time to read? The best glue for MDF projects is a high-quality PVA wood glue, or a strong construction adhesive, depending on your materials.
MDF to MDF (or MDF to Wood): I recommend Elmer’s Carpenters Glue MAX
MDF to Brick, Drywall, or other non-wood materials: I recommend Loctite Construction Adhesive
What is MDF? Is MDF wood?
MDF stands for Medium Density Fiberboard. It’s a composite material made from wood fibers and either glue or resin. Although it’s not technically wood, it’s made mostly from wood, and it has many of the same advantages that wood has, without some of the disadvantages.
It’s cheaper than hardwood, but it’s very dense and strong, thus making it a great choice for furniture and construction.
The biggest advantage of MDF is its uniform density. This makes it great for construction processes where the exact weight of the wood needs to be known beforehand. It’s also used often for speaker housings for this reason.
MDF is actually fairly easy to bond, the best glue to use is a PVA Wood Glue, which forms a bond stronger than the MDF itself. If your project is likely to be exposed to moisture, make sure you use a waterproof wood glue like Elmer’s Carpenters Glue MAX.
So what glue is best for MDF?
(I usually recommend Elmer’s because it’s made in the USA, whereas Titebond is made in China)
MDF isn’t as porous as wood, so the glue can’t seep into the material as much, meaning the bond won’t be as strong as it would be with natural wood, HOWEVER, in most cases, the bond will still be stronger than the MDF itself.
The only other thing to consider is whether or not your MDF project needs to be waterproof. If you’re building something for the kitchen or bathroom or something that will be going outside, you need to make sure the wood glue you choose is water-resistant.
Best glue for MDF Joints
Joining MDF is fairly straightforward, for the most part, you can treat it just like you would a wood joint.
The only difference is with MDF you don’t need to worry about which part of the grain you are joining since there is no grain with MDF.
You can use any PVA Wood Glue, combined with regular screws or nails.
Alternatively, you can clamp your piece after gluing, and no mechanical fastening will be required.
If your project is going to be strictly indoors in non-humid environments, you can use any wood glue you like. I usually recommend Elmer’s Carpenters Glue, but Titebond Original will work too.
If you’re working on a project that may be exposed to humidity (such as kitchen or bathroom furniture) or direct moisture (exterior furniture) you’ll need to use one of the waterproof variants, like Elmer’s Wood Glue MAX, or Titebond III Wood Glue.
How to join MDF Panels Together:
- Make sure your pieces are free from any dust
- Apply your Elmer’s Wood Glue MAX to one or both panels
- Press the panels together
- Either clamp the panels, or use screws or nails to keep the pieces attached while the glue dries
- Wipe up any excess glue with a damp rag while it’s still wet
- The piece will be strong enough to work on after a few hours, but won’t be fully cured for 24 hours
Best glue for MDF to Drywall
Drywall isn’t a super-strong material, it’s not a good idea to have any pressure on it. However, it’s not too hard to glue MDF to Drywall.
Construction adhesive is very inexpensive and works on wood, drywall, foam, tiles, brick, concrete, and any other construction material you could think of.
It’s usually dispensed from a Caulk Gun, but you can buy it in a tube too if you have a very small project.
You may want to supplement the adhesive with some mechanical fasteners. Drywall needs to be fitted with a drywall anchor before you can reliably fasten it with screws. Drywall anchors are a pain to use. If your project doesn’t involve any stress being placed on the joint, you can use the construction adhesive without any mechanical fasteners.
Best glue for MDF Skirting
MDF Skirting Boards are very common and can be fitted easily using construction adhesive.
Almost any construction adhesive will work, since skirting boards don’t have any pressure on them and they are resting on the ground a strong bond isn’t strictly necessary. So, don’t waste your time picking an adhesive, just choose whichever one is cheapest.
The alternative to using construction adhesive is to use a nailgun or a hammer and straight nails to hold the skirting in place.
Best glue for MDF Trim
Like skirting boards, MDF trim or baseboards are best installed with a construction adhesive.
If you’re attaching to wood, it might be easier to use a nailgun, but for all other circumstances, I would recommend construction adhesive. It’s cheap and strong and works well on plasterboard, brick, wood, and MDF alike.
MDF can be difficult to work with, it doesn’t take screws or large diameter nails too well. Using a construction adhesive gets around these issues, and leaves the front side of your new trim unblemished by nails or hammer marks.
It really doesn’t matter which adhesive you choose, there are several popular construction adhesives and they will all work on MDF.
How to Seal MDF:
MDF is extremely porous, making it hard to paint, but there are a few methods we can use to seal and protect the MDF from moisture and to get it ready for painting.
How to seal MDF edges:
MDF is very porous. It soaks up liquid easily, which can cause the MDF to expand and ruin your project and make it very difficult to paint.
The manufacturing process used to create MDF means the edges are even more vulnerable to water than the smooth top and bottom surfaces. This can be a big problem if you’re trying to use stain or paint, or if you want to protect your MDF from moisture.
The edges are the hardest part to seal by far, but if you take your time it’s definitely possible.
To seal MDF edges, first, make sure they are as smooth as possible. Use fine-grit sandpaper (200 and 400 grit) to smooth them down to a smooth finish.
Next, apply the sealant. You can use diluted PVA glue or a vinyl spray sealant. Both work equally well, although the PVA glue will dissolve if exposed to moisture.
It’s likely you will need to repeat the process by sanding the sealant layer and applying another coat to ensure it’s properly sealed.
How to seal MDF before painting:
As per the above instructions for MDF edges, ensure your MDF is smooth before you apply any sealer.
You can choose to use a vinyl sealant again, or you can try a spray-on primer, which will not only seal your MDF but create a perfect surface for paint.
Many of the most popular primers are water or oil-based, however when selecting a primer for MDF, make sure to use a solvent-based product, especially for MDF because it is so porous, some primers that work great on regular wood might not work well on MDF.
Something like this Loctite Spray Primer is solvent-based and will work well on MDF, giving you a perfectly sealed surface to paint.
How to seal MDF from moisture:
It’s a bad idea to expose MDF to moisture, even if it has been sealed beforehand.
In recent years, homebuilding companies have started using sealed MDF for outdoor trim and other exterior fixings. Even though these are sealed and painted, after some time outside they all end up the same. A mushy mess.
To give your MDF the best chance against water, you can seal it with a vinyl sealant, and paint it with a waterproof paint.
However, even with these treatments MDF really doesn’t stand up to moisture, if you’re building something for outside, or something for the kitchen or bathroom where humidity is likely to be high, don’t use MDF as your building material.
How to fill Nail Holes and Screw Holes in MDF
MDF doesn’t take screws very well, because there is no wood grain to grip the screw.
MDF is also not suitable for large diameter nails, but small panel pins and thin nails are fine.
To help hide your nail holes in MDF, you can use a standard wood filler like Minwax Wood Filler that you would use on regular wood. It’s sandable, paintable, and stainable once dry.
How to make MDF look like Wood?
MDF is an ugly product on its own. Although it’s made from wood, it has none of the character of wood.
It has no grain so there’s no point staining MDF, but there are some things you can do to improve the appearance.
Number one and most simple is to paint it. MDF takes paint fairly well as long as you seal it beforehand.
Using a combination of dark and light colors you can achieve a wood-like finish.
The second way to improve the appearance of MDF is to laminate it.
Use a strong contact cement to attach thin laminate sheets to your MDF, which will protect the edges (which are prone to damage) and give the MDF a nice finished look.
Although MDF is not as easy to work with as wood, it’s just as easy to glue.
The best option for MDF is a strong wood glue like Elmer’s Carpenters Glue MAX for MDF to MDF projects, and a construction adhesive like Loctite Construction Adhesive when you need to adhere MDF to other materials like concrete, drywall, plaster, or brick.
Hope this helped, and thanks for reading!