How to fix bulge on wall?

[Hayaimi]

How can I make this bulge in the wall disappear and achieve a smooth finish in the least amount of time and at the lowest cost? 
I previously tried to patch this hole on the wall with Pfeiffer 15cm Plaster Repair Wall Patch and Selleys Spakfilla Rapid Dry. 
And in fear of the wall patch showing through the Spakfilla I overused the Spakfilla that created this bulge (which is around 18 x 19 CM x 4-5 MM thick). Is there a way that smooth the surface without showing the metal patch quickest and at lowest cost? 

 

 

 

 

[JacobZ]

Hi @Hayaimi,

Thank you for your questions about reducing the bulge in your wall.

Plastering is a funny thing because you are aiming to keep things as smooth and imperceptible as possible, logically using less material would be the way to go, but oftentimes, the best way to do this isn't to use less plaster, but to use more.

Have a look near the end of the video in How To Attach And Plaster An External Angle. You'll notice that the plaster ends up being much wider than you would initially expect.

Using a patch like this Pfeiffer 15cm Plaster Repair Wall Patch is a great option, but the thickness of the patch will often show through the plaster. The way to reduce this hump is to apply plaster over a much wider area and feather it out so there is not an obvious change in depth on the wall.

My suggestion is to apply Gyprock CSR Less Mess Topping Compound over the top of the existing plaster and go much wider than you did before. Like the above video, you can use a Hyde 300 x 100mm Drywall Trowel to apply the topping compound, or you could use a Hyde 8" Plasterboard Joint Knife, which I find easier to control.

Once you've applied your topping compound, allow it to dry and then scrape it back with your trowel or joint knife as you see in the above video. Once scraped back, you can assess whether you're happy with the patch, or if you need another coat.

Once happy with the coverage, use a Trojan 120 Grit Angled Sanding Sponge to clean things up and then a Trojan 220 Grit Jumbo Angled Sanding Sponge to get it nice and smooth. You can then paint over the top.

Let me know what you think and if you have any further questions, please don't hesitate to ask.

Jacob

[Hayaimi]

Thank You for the above information. 

So I don’t have to scrape off anything, just apply the toppings on top of the painted area? 
And around how large of an area should the topping cover? 
Are there more affordable alternatives of the products you mentioned? 

[JacobZ]

Hi @Hayaimi,

If you are not confident in your ability to feather the topping compound out to lessen the change in depth from the hump, then it would be worthwhile to remove as much of the old filler as possible, but it is not 100% necessary. 

I don't have a specific size for how much area the topping compound should cover, but a patch that is roughly 60x60cm should be enough to feather it out enough so there is not an obvious hump.

I'm not aware of a cheaper alternative to the topping compound that would be advisable for this project. This Kango 200mm Taping Knife and this Trojan 280 x 130mm Plaster Float are slightly cheaper than the ones I have mentioned and will function much the same.

Let me know if you have any further questions.

Jacob
 

[Hayaimi]

Then which route (lessen the old filler or topping) would be less time consuming, more cost effective and easier for beginners? 
also I would like to know what tools would be fit for removing the old filler for beginners. Can I just do it by sanding? 

[JacobZ]

Hi @Hayaimi,

There will not be much difference in cost as you will need the tools and materials I have mentioned regardless, the main difference is time. The least time-consuming method is to simply coat over the top, but this wouldn't be as easy for beginners. 

I'd suggest it is probably worth investing the time to remove as much of the old filler as possible. The majority of this can be done by sanding, but scraping the filler with your taping knife can also be helpful.

Let me know if you have any further questions.

Jacob

[Hayaimi]

I’m afraid the metal patch might show through the filler and paint again due to the strong dimmer hue of the patch if I remove the old filler and make it flat.
This was also the reason why I applied too much plaster in the patch that erected the bulge, what should I do to make sure the patch is completely concealed? 
Should I remove the metal patch or just use multi-purpose putty on top? 

[MitchellMc]

Hi @Hayaimi,

The amount of filler you used on top of the patch should have been used to spread out around it to taper it into the surrounding wall. My advice at this stage would be to take a sanding float and sand the filler you've applied right back to the patch, until you start to see metal show through. Then, apply topping compound over the patch and around 10cm out into the surrounding area, on all sides. You need to plaster a larger area to conceal the height of the patch. It sounds counter-intuitive, but that's what you need to do with patches that go on top of the wall. Trying to only apply compound over the patch itself is what makes them stick out.

Once the compound has dried, use your sanding float, which has a large flat base, to sand it smooth.

You only need 1mm of compound over the top of the patch to conceal it.

You could remove the patch if it is causing too much difficulty, but you'll then need to fill the hole, before plastering over it.

Please let me know if you have any questions.

Mitchell