Painting MDF

[Prophet]

I've built a floating wall to mount my plasma on. I'm about ready to paint it now and didn't know if MDF primer was that important, especailly as it's much more expensive than standard paint.

Can anyone help?

 

[Sp00n]

If you don't use a decent primer then the MDF will just suck up the paint and the finish will be terrible.

 

[The IPB]

MDF sometimes comes pre-primed, but if yours isn't then it is important to prime the surface before painting. You can use any number of water-based primers, such as an emulsion paint or a proprietary acrylic primer. This base-coat of primer will help give the top coat a truer shade and will prevent it from being affected by the color of the MDF. The primer will also prevent MDF's tendency to result in a blotchy, uneven finish due to its porous surface.

Come on man Google...

 

[_Gizka_]

Tis important in my experience, or the paint will just absorb into the MDF.

One coat of primer, then undercoat, then top coat is what I would do!

*awaits correction*

 

[BloomerzUK]

Tis important in my experience, or the paint will just absorb into the MDF.

One coat of primer, then undercoat, the top coat is what I would do!

*awaits correction*

This is what I'd do .

 

[Werewolf]

Definitely use a primer, it makes a huge difference to how it comes out

Otherwise, as mentioned it just sucks the paint in leaving it with an inconsistent surface.

 

[boxman2000]

I made a desk out of MDF years ago - just used one coat gloss and did the job!

 

[Kutter]

The edges need sealing as the suck up the paint and will have a rough finish as a result. The face sides normally arnt too bad., but just buy a primer then you know that you'll have a good finish.

 

[vectisitch]

i'm a decorator.just use a watered down white emulsion for the primer.it will soak into the mdf and provide a good key for the top paint.just sand in between coats

 

[fornowagain]

I always use some watered down PVA.

 

[Dr.EM]

To make MDF glossy and smooth, in my case to apply high gloss black vinyl finish, you'll need about 2 coats of sealer (Rustins stuff is nice) on the faces and about 4 on the edges. You sand the sealer back with high grit sandpaper (wear a mask), sand between coats ideally, but every 2 coats will suffice for painting. An electric sander is faster but the sealer will form little balls if you don't allow the residue to move off of the work suface.

 

[Prophet]

Thanks for all the advice/info.

The final finish will be matt. Not sure what colour yet but it'll be a slightly different shade to the wall it's mounted on.

 

[Jonny69]

MDF drinks paint

For modelmaking I seal it with a 2-part sealer that the paint won't get through.

 

[setter]

i'm a decorator.just use a watered down white emulsion for the primer.it will soak into the mdf and provide a good key for the top paint.just sand in between coats

This is what i would normally prime mdf with as well, also used acrylic wood primer but emulsion is handy as we buy it in large buckets for contracts.

Thanks for all the advice/info.

The final finish will be matt. Not sure what colour yet but it'll be a slightly different shade to the wall it's mounted on.

Then id suggest emulsion, thin it a bit to help application, particularly on the edges as mdf soaks paint like a sponge, then apply 2-3 coats of your chosen finish colour, lightly sanding between coats.

 

[Prophet]

Then id suggest emulsion, thin it a bit to help application, particularly on the edges as mdf soaks paint like a sponge, then apply 2-3 coats of your chosen finish colour, lightly sanding between coats.

What kind of ratio should I use?

 

[Lakeland]

I always use some watered down PVA.

this. wasting ur time putting loads of layers of paint on. mix pva with water till you have a milky texture and you're onto a winner. give the edges(end grain so to speak) a few coats as this part is less dense and even more absorbant!

 

[Prophet]

this. wasting ur time putting loads of layers of paint on. mix pva with water till you have a milky texture and you're onto a winner. give the edges(end grain so to speak) a few coats as this part is less dense and even more absorbant!

I didn't think emulsion stuck to pva or I'm I thinking of something else?

 

[Lakeland]

I didn't think emulsion stuck to pva or I'm I thinking of something else?

I'd PVA'd then put emulsion on after it had been dried/sanded and it worked a treat, only needed one coat

 

[Albo]

I think everybody has their own way that comes out fine. Depends on what you regard as fine i suppose.

Def use a primer, and SAND between every coat. A good tip for finishing the edges is to use car body filler like P45, come out pukka. Also, if you want to go for a more glossy finish you can actually use car polish and slowly cut it down to a perfect finish.

 

[Dublove]

MDF drinks paint

For modelmaking I seal it with a 2-part sealer that the paint won't get through.

Acid Catalyst?

Thats what we'd use when making any display/exhibition items. 3 or 4 coats of acid cat mdf primer. 1/2 hour drying time then hit it with the orbital. Ready for 2k gloss or whatever then...