No paper tape or scrim used in cracked corner joints. Best way to fix.

[exfatguy]

Can anyone help me please.

I have an alcove composed of 3 plasterboards butt-jointed together, skimmed and painted. There is no paper tape or scrim on the two internal corners. Needless to say that there are cracks from the ceiling to half way down each corner.

So the fix is to scrape away the skim plaster maybe 5cm either side of the cracked corners at a depth deep enough to bury self-adhesive scrim tape and feather the jointing plaster into the existing skim. I will be using multi finish for the joint.

My question is this: what is the best way to scrape away the 5cm wide x 3mm deep skim plaster at the corners? It seems very difficult to scrape a consistent depth all the way down the walls. Putting the scrim on top of the existing skim will mean a visible join.

I really do want to avoid reskimming the whole 3 wall alcove. I just want bury and feather the scrimmed joint as much as possible.

Any help or suggestions or other ways of doing this will be gratefully received. Maybe use caulk!!!!

Thanks.

 

[CJRatch]

I'd rake the cracks out to a couple mm depth, clean off and apply a good flexible caulk working it into the crack and smooth off after. Undercoat the caulk before your emulsion to avoid crazing or use the anti crazing caulk that's available now.

It may return as an hairline crack in the future but you won't care about it by then and will be onto another project ha.

 

[exfatguy]

Thanks for your reply, CJRatch. I really am tempted to caulk it as you say. I have test caulked a small area and used the usual wet finger to smooth off and followed by an oil-based undercoat.

I think that this would be a last resort though. I am doing this for a good friend so was keen to do the job the "correct" way. I have read on the forums that cracking can still happen even with the "industry standard" scrim or paper tape, but at least I will have followed the standard protocol. So I am still open to ideas.