What Is The BEST Way To Paint MDF? - 9 Methods Tested
Painting MDF can be a real chore. Especially trying to paint the edge of MDF. It just drinks up the paint and takes forever to seal. It seems everyone has a different method and recommendation when it comes to painting and sealing the edges of MDF so I thought I would put 9 of those methods to the test.
Methods Tested:
The MDF test pieces were all sanded to 240 grit before applying the different methods.
For the top coats of paint I used spray gloss paint. I chose this because I thought gloss would give the best comparison surface finish between each method. Using spray paint will remove issues like brush strokes and marks left by rollers. I used Rustoleum Mode paint which is actually recommended for MDF on the can.
Method: Iron & Blowtorch
The first suggestion was one I hadn't ever considered before. I was recommended to use heat to seal the MDF before painting. This came in the form of using an iron and a blowtorch. I tried the iron method on the left side of the MDF and the blowtorch was tested on the right side of the MDF.
The iron was set to its highest heat and the steam function was turned off. I applied heat evenly across the left side of the MDF edge. It felt smoother but I sanded it and applied the heat again. This made the edge feel silky smooth.
The blowtorch was used on the right side of the MDF edge. I applied the flame until the MDF was evenly scorched. After sanding it did feel smoother but I applied the blowtorch again for a second coat of heat. After sanding the second coat it felt silky smooth.
Iron
Cost: £0.00 (only cost being electricity which I can see being fractions of a penny)
Coats: 2
Time To Apply: 2m 36s
Blowtorch
Cost: £15.20 (full 0.4kg canister of gas)
Coats: 2
Time To Apply: 24s
Results
After applying 2 top coats of paint sanding between each with 240 grit paper I was really disappointed with the finish. Before paint the surface felt as though it had sealed but the paint just soaked in and made it feel rough again.
The iron side had a flat dull appearance and still felt quite rough.
The blowtorch side felt smoother than the iron side but it was still really dull. It wasn't a great finish.
Overall I would give both these methods 0 out of 5 stars.
Edge Banding
Edge banding has been recommended by loads of people but I've never actually tried it myself.
Applying it was really easy. I cut it to length with scissors.
I could then use the iron to apply it to the edge of the MDF. It sets almost instantly.
There are specific trimming tools you can buy for edge banding but I just used a sharp knife and some sandpaper.
Cost: £8.95 (7.5m roll)
Coats: 1
Time To Apply: 3m 50s
Results
The edge banding was quick and easy to apply. Simple to trim to size and was ready for paint right away. The finish is near perfect!
It gave a silky smooth finish after both top coats of paint. It had a really high gloss appearance too.
Overall I would give this method 5 out of 5 stars.
Wood Filler
I was recommended to use wood filler to seal the edge of MDF but I was also recommended to use car body filler. Rather than buying both to test out I opted to find a middle ground and bought a 2 part wood filler instead. I hope this will offer a good compromise between the two.
Mixing the wood filler is simple. It does have a strong odour to it though so make sure you wear a mask and have plenty of ventilation. It has 10 mins of working time once mixed.
Applying it with a putty knife was simple. I can see it taking some practice to get an even coat over a large area though. It took 30 mins to dry. Once it was sanded it was silky smooth to the touch. The smoothest out of all the methods.
Cost: £1.99 per 100ml
Coats: 1
Time To Apply: 34m
Results
After applying 2 coats of paint and sanding between each the surface felt like glass. But some banding was visible. I think this is where I either sanded too much of the filler away revealing the MDF beneath or I didn't apply the wood filler as even as I thought.
It has a high gloss finish and I would say it is very close to the edge banding in quality.
Overall I would give this method 4 out of 5 stars.
Spackle or Polyfilla
Spackle was another suggestion I had. I believe in the UK we would know it as Polyfilla so that what I got. I hope it's right.
It's really simple to apply with a putty knife. Like the wood filler, I can see it taking some practice to get an even layer though. I took 1 hour to dry and even after sanding it still felt really rough.
Cost: £0.83 per 100ml
Coats: 1
Time To Apply: 1h 2m
Results
After the 2 top coats of paint the surface still felt really rough. I was surprised just how much texture the surface had.
The surface is really pitted and its given a really dull finish.
Overall I would give this method 1 out of 5 stars.
Eggshell Paint
Eggshell paint has always been my go to method for painting MDF. It's really thick which I think is ideal for sealing the edge of MDF.
Eggshell paint is easy to apply with a roller but it can also be thinned down and sprayed too. It took each coat 30 mins to dry and after sanding it felt nice and smooth.
Cost: £0.76 per 100ml
Coats: 2
Time To Apply: 1h 2m
Results
I was actually disappointed with the quality of finish on this one. It didn't have the gloss finish I'd hoped for and it was quite pitted.