How to prepare damaged walls for repainting?

[WreckitRita]

Several years ago, the child painted the toilet walls. 2 days later, the dryer was put on in the adjoining laundry with closed doors, except for the toilet door. No surprises, the paint blistered and that was the end of that joy.  The paint work split as well, with many veins across all the walls. 

Day 1

Enter a lot of life's curveballs across several years... and finally we are here.  I'm scraping walls, discovering the hidden joys of paint scraping and blown plaster with a view to filling, replastering and skimming at a later stage, I assume. 
The map of China wall obviously had moisture trapped between the paint and the plaster and while dry now, it's a clear winner for the disaster awards.

There are four days between first and this second image and it's clearly taking a long time to get through the paint scraping because of the insane adhesion of the paint over the failing plaster.  There was no way to leave the stubborn paint because it had lifted with some of the plaster due to the trapped moisture - become old - and, well - it just has to come off, right?

Day 4

I thought to leave it and seal it (which it seems it had never been before), perhaps try fill the exposed concrete to level out and skim a beaut wall, reseal again and paint.  But I've lost perspective and don't know  where I am, or what I'm doing.
I have Dulux 1 step prep, Gyprock multipurpose joint compound (for some other ceiling work and thought might be good for the skim) - what am I leveling out the blown holes with?
And what am I doing for the rest of the wall(s)?
Am I also looking to waterproof at some point?

The opposite wall with the light switch and other two walls don't have the damage you see on our map of China and surrounding islands.  The paint only seems to go back as far as you can see in the image with the light switch, and attempting to scrape anything else on any of the other walls or areas on the walls either barely scrapes off, or seems to show another colour under the blue paint that we haven't seen before    That colour split can also be seen higher in the middle of our map of China wall (yeah, totally being delirious and stupid to get myself through the trauma of it all.  It's a hard, hot mess and so am I.)

Any product and procedural advice would be really appreciated.
Thanks kindly,
A 60 year old woman with sore hands  

[EricL]

Hello @WreckitRita 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about repainting your bathroom wall.

I suggest investing in a random orbital sander which will help you with the sanding. This tool will create a great deal of sanding dust, and I recommend wearing personal protection such as gloves, goggles and a Citeco Half Face Respirator A1P2 Kit. Most sanding tools come with a packet of sanding pads included, I suggest getting a few extras in the 180grit and 240grit range to strip the wall. I also recommend linking the sander to an Ozito 1250W 12L Stainless Wet And Dry Vacuum to help with the dust.

The general steps will be to remove all the damaged paint and plaster. Clean the wall and floor of dust and debris. Use your shop vac wet/dry vacum cleaner on the wall with the brush attachment to remove the imbedded sanding dust. Once the wall is totally clean then you can plaster the surface to level it back. Then allow the plaster to cure before sanding and cleaning it again before you proceed to painting.

Here is a link to our best advice: How do you prepare a wall for painting? 

I also suggest having a look at these discussions - How to prepare wall for repainting? by @Jams and How to plaster wall after using cement concrete masonry waterproofing? by @DIY_Duncan.

If you have any other questions we can help with, please let us know.

Eric

[WreckitRita]

Thank you so much, @EricL 

I inherited this sander.  Does Bunnings have any discs to suit?  (the folks ran a Hardware store for 40 years)
And... thank you for the links... I have one of them open in my many tabs - and the additional links are priceless.  Many thanks!

[EricL]

HI @WreckitRita 

That is a Ryobi orbital sander, which is perfect for the job. I suggest plugging it in to test and make sure that it still works. Once you've tested it, bring the tool to the shop and test the sanding pads available to make sure they still line up with the vent holes at the bottom. My best suggestion is to get a handful of 140 or 180grit and a few 240grit sandpaper to finish the surface. 

If you need further assistance, please let me know.

Eric

[WreckitRita]

Thanks @EricL  - it does say Ryobi on the side of the first pic? 
It does work.  I actually tried it on the wall at the very first instance, just using the sanding pad you can see.  It barely scratched the surface, even after holding it reasonably firmly in place for a good few minutes.  This paint is really stubborn.
Anyway... I shall get my husband to drive me down to Bunnings and we'll see how we go with the vent holes.    Perhaps some new 140, 180, 240 pads and sheer determination might get me there, assuming the fit is good. Ha!
Fingers crossed.  Onward!

Many thanks, again.

[WreckitRita]

While not perfect, it's so much better.  I'd like to thank you for your help in getting to this stage.
In the end, I hand sanded because the paint was doing nothing to move.  
I watched a couple of YouTube videos that suggested sealing before filling, so I used Dulux Precision Sealer Binder for one coat.
Then light sanded and filled using Gyprock Multipurpose Joint Compound.
24 hours later I hand sanded again. I added a second coat of Precision Sealer Binder.
24 hours later again, 2 coats of Dulux Wash'n'Wear Bathroom and Kitchen Low Sheen.
The last thing to do is to place the new toilet roll holder.  

I'm pretty happy with the results, albeit that my cutting in sucked a bit... the edge of the tiles have sporadic spots of filler, binder and/or paint along them.  But, hey... the room isn't too bad and 100% better than it was.  So thanks again!  Next project.... the dreaded bathroom 😁  Can't wait. 😎

no more World map

[JacobZ]

Hi @WreckitRita,

Thank you for getting back to us with your updated images. You've done a fantastic job and should be extremely proud of the result.

Cutting in is not the easiest thing in the world, but your effort doesn't look bad to me. Trust me, I've done much worse. 

If you want to clean things up a bit, painters will often use utility knife blades to clean up those little drops of paint that end up on surfaces where they aren't intended. Just remember to wear gloves, and a long-sleeved work shirt and be careful with your movements to prevent any risk of unnecessary laceration.

Congratulations on a fantastic job.

Jacob

[WreckitRita]

Thanks, Jacob... and in the light of day, I have a couple of touch up spots to paint, though not many or much. I've rolled a damp roller over the surface of a previously undiscovered drip on the wall which has come up pretty nicely now.  

Ah, yes... the good old utility knife!  Thank you for that tip!  I'll give that a go, for sure.

Most appreciated... thank you!

[Jeanagh]

Hi WreckitRita, you've done a brilliant job. I always put some painters tape along the edge for painting and siliconing, saves those little splodgy bits

[WreckitRita]

Hi @Jeanagh  - I did the stupid thing.  I had painter's tape and a drop sheet down for the first coat of sealer binder, but I got cocky 🤠🤡 and removed it before the compound and the second coat of sealer binder.  Splatters won those rounds and taught me some manners 😄.
I had a second drop sheet there, so I took the time to tape up for the last 2 coats of wash'n'wear. I'll learn eventually 😄
Next project, I'll remind myself there are no short cuts 😂... and thank you! 🌷