Painting Shelves Unit Where It Joins The Wall

[freddiemercurystwin]

So my Ikea Billy Bookcase wall unit is coming along and soon I will be painting it, though I still have some holes to fill, the skirting and then an MDF cover strip will hide all of the joints.

On the sides, the MDF butt up against the wall, the wall is painted (about 18months ago) in Dulux Stain resistant, the MDF is going to be painted in Dulux Satinwood colour white. The wall is far from straight and being no joiner that's as good as I can cut the MDF so there is inevitability a few small gaps as is evident in the photo. I was thinking, as a process the following:

1 Mask the wall about 1mm away form the MDF
2 Caulk the joint with a suitable caulk (any recommendations?)
3 Paint the MDF and inevitably the tiny caulk joint in Bulls Eye 123 primer (as that's also what I'm using for the melamine shelves)
4 Then paint over with the Satinwood

Or is there a better way?

PS don't judge my painting along the dado!

 

[blup]

(Gap) looks OK so why caulk it?

 

[freddiemercurystwin]

Hmm, because there may still be a gap after painting it, seems like I maybe setting myself up for a fall without doing anything with the gap before painting, its slightly bigger in other places.

@opps
@Wayners

 

[Wayners]

Options
Use plasterboard not MDF and fill it to make good.
Fit architrave to cover gaps in that MDF.

 

[blup]

The mdf is proud of the book case so a small beading might help with the transition as well as covering the gap. You've scribed round the dado rail, I found cutting the rail easier especially as it will be a permanent fixture.

 

[freddiemercurystwin]

I'm talking about where the MDF meets the wall, not the gap between the bookcase and the MDF.

I wanted to leave the dado rail, I left the skirting too as I thought if the next person who lives here wants to rip the shelves out then they can do with minimal effort.

 

[opps]

The scribing around the picture rail is pretty impressive- kudos. I don't think that I could have done any better. Caulk will be fine, but there is a very slight risk of it cracking in the future but the risk is so small that you should disregard it.

The counter sunk screw heads- you can use two pack filler but 3-5 years down the line the filler will become very slightly proud of the surface. Not sure why, but when sanded back again it will behave. I would recommend using Red Devil One Time instead tough. It easy to sand, use 180 grit paper and a sanding block.

You can use the same filler to fill the gaps between the mdf and the cabinet.

 

[RandomGrinch]

I've used Toupret fill-flex (fibacryl) for a fill like yours - so far, it's done a much better job of remaining crack free, than a traditional caulk.

 

[opps]

FWIW- my go to caulk is Everbuild 125- I would however recommend that, at a minimum, you prime the MDF first. If you don't, you may find that the MDF sucks the moisture out of the caulk before you can smooth it.

 

[freddiemercurystwin]

FWIW- my go to caulk is Everbuild 125- I would however recommend that, at a minimum, you prime the MDF first. If you don't, you may find that the MDF sucks the moisture out of the caulk before you can smooth it.

Thanks, should I prime the caulk afterwards too or will it be OK to be over painted directly (Satinwood)?

 

[opps]

Thanks, should I prime the caulk afterwards too or will it be OK to be over painted directly (Satinwood)?

Regular caulk will not need to be primed. MS polymers (eg CT1) however need to be primed with water based paints if you are using oil based satinwood. I recommended regular caulk rather than a MS polymer because although the latter is more flexible and will not shrink, your scribing looks to be pretty good.

I would add that if you plan to use masking tape, remove it as soon as you have caulked. If you leave it and then paint, when you remove it, any caulk that has strayed onto the tape will leave a frayed edge when you eventually remove the tape. You can always re-tape when painting.