How to get a smooth finish on plastered walls prior to painting?

[AlexVZ]

We have just started the enormous task of painting our whole house and in doing so have been preparing the walls. It is a brick walled house built 1987. There has been much filling of holes, cracks, chips etc. but two walls (approx. 3m long in total) appear to be badly plastered and have these lines, scratches and uneven sections across the entire wall (other walls had this too but not on such a large extent). We started off just patching the worst bits in this section with multi-purpose filler first but then realised how extensive the scratching/unevenness is and wondered if another approach should be taken..... So, whats recommended - should we just put the filler on the whole wall and then sand back OR do we need something else like a specific plaster filler and repairer OR something else entirely? 

Photos of the damaged walls below, real bad dings and dents have already been patched (yet to be sanded) which can be seen in some of the photos. 

Cheers

[Dave-1]

Evening @AlexVZ 

You are already doing what needs to be done... I have had two walls that had me asking the same questions and both times it came down to continuing and slowly working my way across them.

One wall I swear must have had a teenager jumping on a bed then against the wall as the whole plaster sheet had a "bend" to it. Took awhile and a LOT of sanding but managed to bring it back to look and feel right

My ceiling in the laundry looked a litle like your wall edge, lots of fine plaster fill and sanding then filling and eventually it was like new. I could break walnuts on the muscels of one arm afterwards But yeah, you are doing the right thing, just work your way through it.

Cant resist saying it... Wax on, Wax off...

Would love to see the walls when you finish them btw

Dave

[DIYGnome]

Hello @AlexVZ welcome to the Workshop Community Forums

How to get a smooth surface?

Get one of these puppies... I am still on the fence as I already have a couple of sanders but the plaster dust is insane when sanding 😒

[JacobZ]

Hi @AlexVZ,

Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you join us.

It's great to see you've already had some advice from @Dave-1 and @DIYGnome.

My suggestion would be to grab a Hyde 6" Plasterboard Joint Knife and a bucket of Gyprock CSR 2.25kg Less Mess Topping Compound, or better yet Gyprock 15kg Gold Topping Compound if there is enough area to justify the larger bucket.

These are both topping compounds that are designed to be very smooth and easily sandable. You'll be far better off using a plaster topping compound than a general-purpose filler in your situation. 

Applying a skim coat to fill the gouges and low spots will make the job of sanding much easier and negate the risk of removing too much material and revealing the tape and trims underneath the existing plaster.

Remember, plastering is all about applying material and gently removing it, so don't be too careful or localised with your application. Going much wider with your skim coat than you would expect is going to produce better results.

Once you've applied your skim coat, as DIYGnome has said, a Full Boar 750W 225mm Drywall Sander Kit will make the job of sanding much easier, but if you can't justify the expense, a Hyde 225mm Radial Sander Plaster Tool with a ProRenovator 1.0 - 1.8m Aluminium Extension Pole will be fine.

You might like to check out How To Patch Plaster for a bit of additional guidance.

Please remember when sanding to wear a mask and eye protection. I know all too well how painful plaster dust in the eyes can be, so please take the precautions necessary to prevent unnecessary injury.

Let me know if you have further questions.

Jacob

[AlexVZ]

Thanks @Dave-1 @DIYGnome and @JacobZ . 

The advice and encouragement is much appreciated. We will give it a go and will definitely post some final stage pictures. At this rate we may be done by Christmas haha as planning to do the whole house and everything else in between! 

Cheers, Alex