Feb blue grit not bonding properly

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Hiya , I hada mare yesterday !
laid a ceiling on in a room I had prepped previos day , worst set ever !
I had blue gritted it with Feb bond as all walls and ceiling had a shiny greasy finish ! I normally use pva when overskiming existing unless its silk paint and the pva wont take to the waterproof surface so I grit it to get the right suction level and a secure bond .
Yesterday however this was not the case ! While laying it on the bonding failed in sevral areas pealing and falling from the ceiling like missed patches of wallpaper , causing patches of muck to fall! I squeezed fat into the areas and tried to save them !
On flatten 1st coat it hung wet asf ! Creating bubbles I blasted over it with plastic to take out the bubbles n was putting it down to the fact I had laid it on thicker to cover the grit .
, the ceiling was still wet almost 4 hours later , every trowel pass was a nightmare ! Creating ripples and tears in the plaster ! I have never experienced this before !
I blue gritted the walls the same as the cieling and need to pop back and skim them but am scared the same will happen or that when I return I'm gona spot a blow in the ceiling an have to hack it off any suggestion as to what could have caused this ??
 

Gilbert75

Well-Known Member
Hiya , I hada mare yesterday !
laid a ceiling on in a room I had prepped previos day , worst set ever !
I had blue gritted it with Feb bond as all walls and ceiling had a shiny greasy finish ! I normally use pva when overskiming existing unless its silk paint and the pva wont take to the waterproof surface so I grit it to get the right suction level and a secure bond .
Yesterday however this was not the case ! While laying it on the bonding failed in sevral areas pealing and falling from the ceiling like missed patches of wallpaper , causing patches of muck to fall! I squeezed fat into the areas and tried to save them !
On flatten 1st coat it hung wet asf ! Creating bubbles I blasted over it with plastic to take out the bubbles n was putting it down to the fact I had laid it on thicker to cover the grit .
, the ceiling was still wet almost 4 hours later , every trowel pass was a nightmare ! Creating ripples and tears in the plaster ! I have never experienced this before !
I blue gritted the walls the same as the cieling and need to pop back and skim them but am scared the same will happen or that when I return I'm gona spot a blow in the ceiling an have to hack it off any suggestion as to what could have caused this ??
Maybe distemper on ceiling, walls more than likely be fine.. overboard ceiling.
 

MakeItSmooth

Well-Known Member
Hiya , I hada mare yesterday !
laid a ceiling on in a room I had prepped previos day , worst set ever !
I had blue gritted it with Feb bond as all walls and ceiling had a shiny greasy finish ! I normally use pva when overskiming existing unless its silk paint and the pva wont take to the waterproof surface so I grit it to get the right suction level and a secure bond .
Yesterday however this was not the case ! While laying it on the bonding failed in sevral areas pealing and falling from the ceiling like missed patches of wallpaper , causing patches of muck to fall! I squeezed fat into the areas and tried to save them !
On flatten 1st coat it hung wet asf ! Creating bubbles I blasted over it with plastic to take out the bubbles n was putting it down to the fact I had laid it on thicker to cover the grit .
, the ceiling was still wet almost 4 hours later , every trowel pass was a nightmare ! Creating ripples and tears in the plaster ! I have never experienced this before !
I blue gritted the walls the same as the cieling and need to pop back and skim them but am scared the same will happen or that when I return I'm gona spot a blow in the ceiling an have to hack it off any suggestion as to what could have caused this ??

Was the house built late 19th / early 20th century?

Maybe distemper on ceiling, walls more than likely be fine.. overboard ceiling.

I was thinking the same.
 

Steve Brown

Well-Known Member
I recon distemper or dirty greasy surface that should always be sugar soaped beforehand.
I personally don’t like blue grit but do rate bg bond it (good old pva 95% of jobs) but you should always prep surfaces before as no matter how good the bonding agent if the background’s shite nothing will suffice.
 

Wayners

Well-Known Member
Come on everyone... Sugar soap. No. Sugar soap is used as a chemical cleaner but not very strong and don't leave soap residue. Always use something better prior to sugar soap or like me don't bother with it. Worlds moved on and get some Virosol. Surfaces need to be clean and you want something fast and easy to use (cheap too) as the water based sealers won't stick to dirty surfaces. Use sponge or spray bottle 50-1 Virosol or a tad stronger but not too strong as may leave residue. I use window cleaning T bar thing as quick to wipe over. Then blue grit or pva
IMG_20200819_095524_compress32.jpg


£10 for 5lt and will make enough to swim in. We use at home to..
IMG_20201023_191722_compress32.jpg


Neat it will devolve oil paints in 24h
 

MakeItSmooth

Well-Known Member
Isnt distemper soft and dusty finish tho ? This was glossy in shine , thats why I blue gritted it in the 1st place cus it looked as if the pva wouldn't take to it !

Quite a few Victorian & Edwardian properties I've seen have a thin, almost hard/polished clay-like surface on the ceilings (or it could be described as feeling like hard greasy chalk) - I've seen it near-white or very pale blue-grey. Almost always, there is a layer of wood-chip wallpaper on view, underneath which is a layer or two of decades-old paint (predictably) peeling like crazy, because it's failed to adhere properly to the clay-like surface beneath it. It doesn't play well with new plaster or even with wallpaper. Given the choice, I feel overboarding can be a peace-of-mind option, but I'm considering buying and trying a scabbler, the next time I encounter this type of surface. It might be too aggressive (especially if the problem surface is layered on weak substrate), but I won't know unless I try.

I've seen the more powdery surface generally referred to as distemper, and I can't help wondering if it might perhaps be the same stuff, only more degraded. As I'm sure many TPFers know, there are some chemical products that claim to deal with distemper (e.g. Toupret Wall Hardener Stabiliser, Zinsser Gardz, etc.), but they're expensive for the amount of area they cover, and I'm wary of trusting them with dodgy surfaces, to hold plaster (but eager to learn from anyone who's found a reliable solution, prior to adding a layer of PVA/Grit. I know there's decades and decades of combined experience, on TPF).

By the way, here's what wiki has to say about distemper:

Distemper is a decorative paint and a historical medium for painting pictures, and contrasted with tempera. The binder may be glues of vegetable or animal origin (excluding egg). Soft distemper is not abrasion resistant and may include binders such as chalk, ground pigments, and animal glue. Hard distemper is stronger and wear-resistant and can include casein or linseed oil as binders.
 
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Wayners

Well-Known Member
I had distemper this week. Festool ets 150mm orbital sander with 80g mesh to take off surface linked to vac, then beeline sealer 3-1. Let that dry and rock spoiled. Pva and skim. Screwfix sell giraffe sander cheap and that will do it with 80g 225mm discs. Just get the surface off and the beeline sealer will do the rest. Blue grit would also take hold to as used that before to seal after sanding. Used to wash off but takes too long and a mess. Half hour sanding and get on with it
 

Stevieo

Royal Spin Doctor
Isnt distemper soft and dusty finish tho ? This was glossy in shine , thats why I blue gritted it in the 1st place cus it looked as if the pva wouldn't take to it !
I had same recently. The great and good advised that blu grit/bond-it is likely to fail when applied to shiny greasy substrate as you describe.

I had it coming through like wallpaper in places. Thankfully only in very small areas that I was able to sort out.
 

Zippydragon

Well-Known Member
I had the exact same 2 weeks ago. Was fbloody nightmare. Had another spread on job with me and he had same issue.
 

FreeD

Private Member
You could decrease it then use Zinsser Gardz followed by blue grit.

If possible just overboard.
 
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