MDF stud wall screws and gaps covering?

[CA101900]

Hi, new here. Total novice, in reality, at DIY stuff. I've had a go at a few things but have usually assisted rather than anything else. I've built stud walls before, and have built one in my current place, but it's a bit different in that it's MDF over the stud wall rather than PB, for various reasons. I've not used it before, and in short, I'd appreciate some basic advise on:

1. The best way to cover over screws and fill a few gaps in between the panels (warped ceiling means perfects cuts weren't possible). I've got some polyfilla, and some Ronseal wood filler. Which of these would be best?
   
2. Effectively seal the ends of the MDF boards. They've been sanded down and are flush with the timbers, but I know they contain formeldeyhyde etc. so I'd like to seal them, atmospherically speaking - particularly because it's a partition to create a wall for my son's bedroom. There seems to be a lot of conflicting information about this, from 'just paint over' to 'use a tape of some kind' to 'use wood filler in thin application' to 'varnish' etc. Pretty sure some of these are weird ideas..

I'm not hugely bothered about the quality of the finish. as long as it looks essentially ok. I'd like to make it fairly quick and simple, as time is quite limited for me at the moment, so ideally the next step would be to paint it white as simple as possible. Not fussed about a million primers, undercoats and so on.


Any ideas about these would be appreciated.

 

[CA101900]

Am I in the wrong sub-forum? Would this be better in the building part?

 

[JohnD]

For the moment, let's just assume that all the decorators are sitting in the sun with a bottle of beer and a charred burger, instead of crouched over their keyboards.

 

[CA101900]

It's a fair assumption. More or less, it's where I've been for the last two days.

 

[misterhelpful]

Car body filler is good for the holes over screw heads, and also for any joints. All purpose ready mixed fillers do the job but may become more noticeable in time. Where the board meets the ceiling or another wall, decorator's caulk is the best option as it will expand and contract a little to allow for any movement.

You can paint MDF directly with a good quality emulsion, but water down the first coat around 10% to make application and coverage easier and better. Follow up with another coat or two of neat emulsion, and you'll be done. A lot of people recommend MDF primers, and they do a good job, but emulsion applied as above does just as good a job.

Once painted, the MDF is effectively sealed and any nasties are trapped....until the bogeyman hidden in the wall escapes!

 

[CA101900]

Perfecto; just what I was looking for. Appreciate your help!