Wall filler problems

[HMLKS]

Hi.

I am repairing walls in one of the rooms. I have applied skim coat on 2 walls and filled imperfections on another 2.

The problem which I am facing that the areas which I have filled and sanded flat is proud after I apply paint.

I am 100% sure that I sand areas flat and nice before painting. But once I apply paint those areas becomes proud and visible. I am not talking about flashing though paint, I am talking about filled area becoming more proud (most likely expandint because of paint).

When sanding I am using LED light to check, it looks just perfect before painting. No proud edges, everything super smooth, can't feel when touch, LED light shows no imperfection.

I have tried couple fillers:
Tourpet powder filler, Tourpet ready mixed filler (sets more harden than powder), Easyfill 60.

I also mist coat areas before painting. But it still happens with all fillers.

What I am doing wrong? Now the last option option in my mind is to try Zinser peelstop or GARDZ.

Thank you in advance!

 

[RandomGrinch]

What I am doing wrong? Now the last option option in my mind is to try Zinser peelstop or GARDZ

Try some Gardz, it's good stuff.

 

[HMLKS]

Try some Gardz, it's good stuff.

If I spot prime with Gardz it won't flash though emultion vinyl matt? Thank you

 

[RandomGrinch]

If I spot prime with Gardz it won't flash though emultion vinyl matt? Thank you

I've only had a problem once - I was sealing some fill on a dark painted wall. Even after several re-coats, when hit by the light, it was still obvious where the patching had been - the colour was slightly off.
However, this may have been down to the quality of the Wilko paint I was using!
With different paint and lighter colours, I haven't had any issues.
I also like to feather out the Gardz by lightly dry brushing it onto a small area surrounding the patch, before it dries.

 

[muh3]

Spot priming might leave you with a similar problem, but this time the gardz area will be flatter. Paint the whole wall with gardz or any other good primer.

 

[foxhole]

Once sanded wipe area with damp clothe and run you hand over the area , sense of touch is more accurate than vision at picking up imperfections.Or hold a straight edge against wall .

 

[HMLKS]

Once sanded wipe area with damp clothe and run you hand over the area , sense of touch is more accurate than vision at picking up imperfections.Or hold a straight edge against wall .

Thank you for reply. I am 100% sure that I sand area perfectly. I am carpenter by trade and used to sand things. The problem rises after painting. I am looking for perfect finish, using light to spot imperfections, not trying to go cheap with paint as well. Using Dulux Trade Vinyl matt. Tried Tourpet powder and ready mix. Tried easyfill 60. Same story.

When I am working on site I can't see painters using gardz or other primers after spot fill. Most of time they just mist coat area and somehow it works for them.

 

[muh3]

Thank you for reply. I am 100% sure that I sand area perfectly. I am carpenter by trade and used to sand things. The problem rises after painting. I am looking for perfect finish, using light to spot imperfections, not trying to go cheap with paint as well. Using Dulux Trade Vinyl matt. Tried Tourpet powder and ready mix. Tried easyfill 60. Same story.

When I am working on site I can't see painters using gardz or other primers after spot fill. Most of time they just mist coat area and somehow it works for them.

The problem you have is that the filled area takes a lot more paint. I would guess the walls had been painted with vinyl before. So you have very low suction on the Vinyl against very high suction on the mist coat.

I guess if you are talking on site you are talking freshly plastered walls with filled areas, they are all high suction and the problem is not that noticeable.

I had a similar issue before, the plasterer spattered some pva on a newly plastered wall making the splatters low suction. I did not notice until i pained and you could see all the spatters on the wall. I spot primed and i ended up with bigger patches you could see. Only option you have is to make the whole wall the same suction.

 

[opps]

As a decorator, I can honestly say that I have never seen Toupret swell when painted. Theoretically, it doesn't need to have a mist coat, nevertheless I do apply one, in part to ensure that any dust on the surface of the filler is locked in.

Interior wall filler : Achieve a Seamless Finish | Toupret Uk

Discover the best interior wall fillers for achieving a seamless finish. Say goodbye to unsightly gaps and cracks. Get expert tips on proper application techniques and product recommendations for flawless walls.

www.toupret.co.uk

What grades of abrasives are you using? If not using a DA sander or similar, a sanding block might be useful.

 

[HMLKS]

As a decorator, I can honestly say that I have never seen Toupret swell when painted. Theoretically, it doesn't need to have a mist coat, nevertheless I do apply one, in part to ensure that any dust on the surface of the filler is locked in.

Interior wall filler : Achieve a Seamless Finish | Toupret Uk

Discover the best interior wall fillers for achieving a seamless finish. Say goodbye to unsightly gaps and cracks. Get expert tips on proper application techniques and product recommendations for flawless walls.

www.toupret.co.uk

What grades of abrasives are you using? If not using a DA sander or similar, a sanding block might be useful.

Well, it's happening to me for some reason. And it's super annoying.

I prepare wall until perfect condition using orbital sander and sanding by hand with 180grit. Until light shows no imperfections, smooth to touch, not visible by eye. I remove dusts and then paint. And after paint all my hard work filling and sanding becomes worthless because those filled areas raises.

I found one thread where person faces exactly the same problem:

Filler changing shape when painted or primed

I prepped my walls, lovely and flat, but made the mistake of using easifill, so having read about it flashing, I did some reading and used Gardz as there was quite a lot of filler, but it was most definitely flat visibly, and to the touch. When the Gardz dried, the filler had changed shape, it...

www.diynot.com

 

[HMLKS]

Any thoughts if I try Leyland Acrylic primer undercoat?

 

[HMLKS]

Tried Leyland Trade Acrylic Primer Undercoat. Had to thin it down with water because otherwise it just dries instantly and creates ridges.

Filled areas still raises once I apply "mist coat" with this primer.

 

[opps]

The only thing I can think of is that when you apply the paint, the water in the paint soaks through to the old paint and lifts the old paint (pulling the filler forwards). If the original plaster was not properly misted (or is distemper), the only thing I can recommend is sealing the areas with something like an alcohol based shellac paint, eg Zinsser BIN or Blockade by Smith and Rodgers (which is just as good but cheaper).

 

[HMLKS]

The only thing I can think of is that when you apply the paint, the water in the paint soaks through to the old paint and lifts the old paint (pulling the filler forwards). If the original plaster was not properly misted (or is distemper), the only thing I can recommend is sealing the areas with something like an alcohol based shellac paint, eg Zinsser BIN or Blockade by Smith and Rodgers (which is just as good but cheaper).

Thank you for advice. I tried acrylic primer undercoat without adding water to it and it looks like it worked well. Finally smooth wall