How to cover cracks like this

[ax222s]

Hi,

Ive had this crack for a few years since I moved in. (Its not subsidence).



I wiped some caulk on it which initially hid the crack. (I was planning on painting over it at a later date). However it seems the crack is now back! (its no bigger than the original crack, so its not subsidence). Theres various other cracks where the walls meet the ceiling too.

Is there something better I can use to hide the crack and then paint over it?

Thanks

 

[Bonni]

A guy on YouTube recommended scraping the crack out, spraying foam in, scrap hard foam to just below surface, fill, sand and paint. Never tried it.

 

[ax222s]

Thanks, but the crack is really small - almost a hairline crack. (the photos probably make it look bigger than it actually is). I dont think Id manage to get the foam in there.

 

[Chivas69]

You can slightly take it out a bit with a hook scraper. This will give it a nice V shape. Then put in some sandable polyfilla and rub level when dry.
Before painting put some acrylic primer/undercoat on the sanded down filler to stop it flashing through!

 

[BlueLoo]

Highly recommend you use the polymer based, ready mixed fillers.
They can be a bugger to sand but are much more compliant and tenacious for filling cracks than the Plaster of paris std stuff.

 

[Bonni]

I would whole heartedly avoid ready mixed fillers, unless you want to sane your plaster away before barely scratching the rock hard filler.

Cracks normally re-open. Some people scrape the crack out deeper and try different fillers and even caulk. Caulk sinks though and if you fill over caulk, the filler falls out when you sand it.

You could cut the plaster an inch either side of the crack, chip the 3mm top coat of plaster off, put scrim tape in and fill over.

The problem is the background, so if the background expansions and contracts at that point, the hairline crack more often enough reappears.

 

[Old Salt]

I have had success with cracks using “one strike filler” from tool station. As others said scrape out the crack first then fill.

 

[ax222s]

Thanks guys. The crack is literally only 1/2mm wide. Will I have to scrape out crack etc first? I was hoping I could simply wipe... something... over it, then paint over the top.

 

[Chivas69]

The scrape out is just to help with the bonding. Getting filler into the gap means it's less likely to come back

 

[ax222s]

Ah I see - thankyou, i shall do that!

 

[opps]

Faced with cracks like that- I rake out, brush in PVA, wiping away the excess. I then gun in some Toupret Fibacryl (it is like a caulk with fine fibres in it), run a filler knife over it to push it in to the gap. Scrape off the excess with the filler knife. Leave it for a day or so as it will shrink back. I then do a final fill with a soft, lightweight filler such as Red Devil OneTime.

 

[ax222s]

I was in B&M yesterday. Perhaps one of these will do the job?

 

[opps]

I was in B&M yesterday. Perhaps one of these will do the job?

View attachment 258419 View attachment 258420 View attachment 258421

I haven't tried any of them.

If you are planning to ONLY rake and fill, and want to keep costs to a minimum, then rather than any of the above, I would say go for the OneStrike filler recommended by @oldsalt.

https://www.toolstation.com/one-strike-ready-mixed-filler/p20822

£3.99