Painting MDF

xyz123

hi

we recently had 1 inch MDF shelves put in a closet as shoe storage. these have been glued to wall and support battons.

any tips on painting MDF. heard abt this special MDF primer to make sure the wood dosnt absorb pain and expand! is it really required. had a look in wickes, MDF primers were quite expensive.

also any recommendations as to oil or water based primer and paint to use? being shoe storage it doesnt need to be of top quality finish.

ta

Sgt_Pepper_2

I wouldn't use water based on the end of the board.

LEJC

we have had some doors made with some of the work being done in MDF...and have also been told to use the MDF primer...

Found it reasonably cheaply in Toolstation...you might want to have a look there if you have one near you....a little does go a long way ...from memory it was £7ish

xyz123

Sgt_Pepper wrote: »

I wouldn't use water based on the end of the board.

interestingly, the MDF primer from toolstation is water based!

xyz123

LEJC wrote: »

we have had some doors made with some of the work being done in MDF...and have also been told to use the MDF primer...

Found it reasonably cheaply in Toolstation...you might want to have a look there if you have one near you....a little does go a long way ...from memory it was £7ish

is toolstation trade only or open to public as well?

cyclonebri1

Just use oil based undercoat it works fine.
You will need a couple of coats and then let it dry for a few days then sand the dust and "grain" that will have raised.

Also, it's important to paint both sides, mdf is very quick to react to a moist atmosphere and will likely bow if not so treated.;)

LEJC

xyz123 wrote: »

is toolstation trade only or open to public as well?

its trade and public....

xyz123

cyclonebri1 wrote: »

Just use oil based undercoat it works fine.
You will need a couple of coats and then let it dry for a few days then sand the dust and "grain" that will have raised.

Also, it's important to paint both sides, mdf is very quick to react to a moist atmosphere and will likely bow if not so treated.;)

Do u mean two underoats, sand and then paint? Is it a must to sand. Is it cos mdf will "expand" after first coat? Also if mdf absorbs moisture, how come the special mdf primers water based?

Sorry for basic question but haven't painted wood before.

cyclonebri1

xyz123 wrote: »

Do u mean two underoats, sand and then paint? Is it a must to sand. Is it cos mdf will "expand" after first coat? Also if mdf absorbs moisture, how come the special mdf primers water based?

Sorry for basic question but haven't painted wood before.

Yes to everything you have said.

Almost all paints and primers are water based today, if you by an audi it's done in water based paint, all to do with the environment and precious little to do with making a better paint.

A personally avoid water based stuff whenever possible, but it does have the advantage of being quicker drying in general.;)

jcb208

Water based primer or even emulsion will be fine been using water based on MDF since the horrid stuff came out and never causes a problem

Leif

Just apply two coats of acryclic water based MDF primer followed by a couple of top coats using a mini roller. Give it a light sanding between coats to removes nibs, stuck on hairs etc. You might have to sand the ends after each coat as they are more absorbent. Yes MDF does absorb water and expand, but a couple of coats of acrylic primer will seal it even though it contains some water.

Ronseal Diamond paint is a good option for the top coats, it's water based so brushes are easy to clean, and it is very tough, but use a roller not a brush, as you'll see the brush lines. I used Dulux emulsion on a cover for some pipes as I had some lying around, looks fine.