MDF, Priming, Undercoat, Emulsion and gloss question

[chapsuk]

Hi all.

I have some 18mm mdf that i need to paint.

Having read some of the posts on here and the interweb, am i correct in the assumption:

1. MDF will have to be primed and not glossed [Crown water based quick drying ie piccy -> http://tinyurl.com/CrownQuickDryGloss ] directly.
2. Have to buy a MDF primer [ like http://tinyurl.com/oc8ubkt ] or alternatively mix Emulsion&water with ratio 75/25%
3. Having said of the emulsion and no access to MDF primer, would Crown matt magnolia [ here -> http://tinyurl.com/CrownMattMagnolia ] be any good to use, then gloss white as above]
4. Use a small emulsion roller [and not a gloss] instead of a brush. I do have the Harris Finesse brushes that I always gloss with

All coats obviously need sanding before and between etc.

mtia for comments/pointers

 

[Rob0482]

It depends on whether you have any edges of the MDF to paint, or whether it's just flat smooth faces.

I just did some shelves which were new 25mm moisture resistant MDF, and I gave them 1 coat of watered down white acrylic primer (about 65/35 paint to water) on the faces. I also gave the raw edges 3 coats, and sanded between coats then applied a very fine layer of lightweight filler to them, sanded and primed a 4th time.

After that, 2 coats of Dulux Trade Satinwood and they have come up great.

If you have any offcuts of MDF, try some thinned emulsion/acrylic primer on it. Anything will work, but if you use magnolia, it may take an extra topcoat to completely obliterate it - depending on what you use.

I'd also see how your roller lays down the gloss, vs the brush on the offcut, as it may not give a smooth finish. A combo of the two could be an option though - lay on the paint with the roller, then smooth with the brush.

 

[jcb208]

Not ideal but you can emulsion it.Best to use a water based primer undercoat as the edges will rub down better as it drys harder then emulsion