MDF finishing

[signalman steve]

Gday folks, having problems with getting a decent finish on some MDF signs I’ve made . Have tried yacht varnish and osmo but both look blotchy , any idea please ?

 

[Essex Barn Workshop]

I can only tell you what works for me.
seal MDF before painting, fine sand (320 grit+) after first coat.

 

[signalman steve]

I can only tell you what works for me.
seal MDF before painting, fine sand (320 grit+) after first coat.

Thanks

 

[robgul]

@petermillard is your man here - seems to do roller and spraying on MDF

 

[Spectric]

MDF does seem to grow hairs when painted, suppose that is why you sand after 1st coat, to remove them.

 

[petermillard]

Yacht varnish and Osmo? Sounds like you want the natural beauty of the MDF to show through?? That’s not something I’ve ever been asked for tbh. For painting, I don’t do anything special - a water-based acrylic primer undercoat, followed by a water-based acrylic topcoat in the finish of your choice, with a light de-nibbling in between each. The trick - such as it is - is to start with quality, MR (Moisture Resistant) MDF from a known manufacturer eg Medite, Finsa, etc… MRMDF is a much better quality board for not much more money, and I would always recommend seeking it out in preference to regular MDF.

I detail my painting process in this video - it’s specifically about painting doors, but the same principles apply. HTH. P

 

[signalman steve]

@petermillard is your man here - seems to do roller and spraying on MDF

Thanks will have look

MDF does seem to grow hairs when painted, suppose that is why you sand after 1st coat, to remove them.

sure does , I’ve gone and got some sealant as advised so fingers crossed

Yacht varnish and Osmo? Sounds like you want the natural beauty of the MDF to show through?? That’s not something I’ve ever been asked for tbh. For painting, I don’t do anything special - a water-based acrylic primer undercoat, followed by a water-based acrylic topcoat in the finish of your choice, with a light de-nibbling in between each. The trick - such as it is - is to start with quality, MR (Moisture Resistant) MDF from a known manufacturer eg Medite, Finsa, etc… MRMDF is a much better quality board for not much more money, and I would always recommend seeking it out in preference to regular MDF.

I detail my painting process in this video - it’s specifically about painting doors, but the same principles apply. HTH. P

I’m all for using what’s on the shelf but point taken , will have a sly g+t sit down and watch some painting porn ….cheers