Caulk splits under emulsion

[PurdeyKingandQueen]

What is the best solution to stop caulk from 'splitting' when you over paint with emulsion . Usually in wall returns and along wall/ceiling line .
Always leave caulk to dry totally before painting over, and paint never too thick.

 

[confidentincompetent]

Matt emulsion will crack (not the caulk) when it dries on caulk, Apply caulk, allow to dry, prime the caulk with solvent based undercoat (feather out dont leave any thick edges) allow to dry then carry on ..
Sometimes soft sheen and silk emulsions will take on caulk without cracking, somethin to do with tension when drying....Zampa will explain more......

 

[Nige F]

yeah I get real tense watching my paint dry I`m going for a lie down now.

 

[Zampa]

Matt emulsion will crack (not the caulk) when it dries on caulk, Apply caulk, allow to dry, prime the caulk with solvent based undercoat (feather out dont leave any thick edges) allow to dry then carry on ..
Sometimes soft sheen and silk emulsions will take on caulk without cracking, somethin to do with tension when drying....Zampa will explain more......

Nope...















Nothing to add to that really...but im sceptical about the oil based undercoat though..unders is almost as brittle as matt emulsion..I cant see the benefit personally.

As CC said...leave it to dry, thats the main thing, they say you can paint over caulk in an hour..I dont agree, if its thick and deep it could take days to dry well enough take a coat of paint.

Being a true pro I never paint over it for at least three weeks...

 

[Zampa]

Matt emulsion will crack (not the caulk) when it dries on caulk, Apply caulk, allow to dry, prime the caulk with solvent based undercoat (feather out dont leave any thick edges) allow to dry then carry on ..
Sometimes soft sheen and silk emulsions will take on caulk without cracking, somethin to do with tension when drying....Zampa will explain more......

Nope...





































Nothing to add to that really...but im sceptical about the oil based undercoat though..unders is almost as brittle as matt emulsion..I cant see the benefit personally.

As CC said...leave it to dry, thats the main thing, they say you can paint over caulk in an hour..I dont agree, if its thick and deep it could take days to dry well enough take a coat of paint.

Being a true pro I never paint over it for at least three weeks...

 

[confidentincompetent]

Nope...















Nothing to add to that really...but im sceptical about the oil based undercoat though..unders is almost as brittle as matt emulsion..I cant see the benefit personally.

As CC said...leave it to dry, thats the main thing, they say you can paint over caulk in an hour..I dont agree, if its thick and deep it could take days to dry well enough take a coat of paint.

Being a true pro I never paint over it for at least three weeks...

Can say the unders is well tried and tested steve m8.
The undercoat seems to dull the caulk enough for the matt emulsion to dry without mudcracking effect.[/b]

 

[Growler]

Going on Spice's recommendation,i've used undercoat over caulk on dozens of occasions now.
Worked every time for me , it's the best tip around.

 

[spice]

Going on Spice's recommendation,i've used undercoat over caulk on dozens of occasions now.
Worked every time for me , it's the best tip around.

 

[Zampa]

Worth a go then...i'll give it a try..

 

[spice]

Going on Spice's recommendation,i've used undercoat over caulk on dozens of occasions now.
Worked every time for me , it's the best tip around.

Just out of curiousity Growler, did you UC straight after you caulked it, or did you wait for the caulk to dry?

I have tried it a few ways, I have waited a couple of hours,also waited till the next day, but I was in a bit of a rush the other week, and needed the caulking out the way, so I caulked it, then UC about 30 mins afterwards, was a bit worried it might have cracked, but went in the next day, and was crack free, then did the normal emulsion and kept checking it for a couple of days, and still no crazing.

I am not saying it works every time, but I can only say that it has worked every time with me.
I usually leave it till the next day anyway to paint over, but one lot crazed on me after I emulsioned the next day, so to be on safe side I UC it.

 

[Growler]

Spice -
I've always done it the same day, usually over a lining job.

I usually don't carry any oil undercoat so because of you, (again) I bought some cheapo Macphersons oil u/c (£6,50 2and a half litres) cos I was sick of it cracking.

Done several houses throughout and always caulked the same day (thin bead) then, gently, with a 2" purdy and unthinned/unstirred u/c.

Done all my own house and for a test, undercoated all caulk except 1 wall. Everythings perfect except the 1 wall, which started to crack after a couple of weeks and just seems to get worse. (Dulux Decorators caulk)

This caulk/cracking has been a real pain, even if you leave it to harden , it can still crack so............ to apply oil undercoat over caulk is the best tip I've ever come across on a decorating forum and thanks to Spice, it's saved me loads of grief.