How to prep wall for paint

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hsvhel

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#2450239 30-Mar-2020 18:48

mdf:

Quickdry is pretty amazing stuff and will cover up all manner of sins, both surface quality (within reason) and any patchiness in colour that you are overcoating. You don't strictly need it, but some colours/tints definitely conceal what's underneath better than others. Better IMHO just to do it properly with an undercoat than end up doing a third or fourth top coat to get the finish you want.

No worries about overcoating acrylic over oil, so long as the oil is _thoroughly_ dry. I've just checked the label online and it claims 3 hours but I usually aim for next day to make sure.

Are you a decorator by chance? sounds like you've done this a few times!!

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mdf

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#2450245 30-Mar-2020 18:59

hsvhel:

Are you a decorator by chance? sounds like you've done this a few times!!

😀

Far from it nowadays, but worked in a Resene colorshop many years ago as a student job.

And have painted *quite* a few times since then. From the lessons heard the hard way file:

1. It will take longer than you think. And you already think it will take longer than you think. Allow even more time.

2. There might never be time to do it right, but remember, you will have to find the time to do it over.

3. Drips will always be at eye level.

4. Yes, I know you can just squeeze in the last coat before dinner/bed, but if you do, you will stuff it up and end up doing another coat the next day anyway - see (3).

5. You will always miss at least one nail hole.

6. No matter how long you spend at Bunnings, you will always have forgotten or run out of something before the job is done.

7. Buy a rat tail cutting in brush. In fact, buy two (25 + 38 mm). Clean them properly and treat them right and they will pay back the investment in spades.

8. A coat hanger is the most useful painting tool there is. Go on, guess how.

hsvhel

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#2450279 30-Mar-2020 19:55

mdf:

hsvhel:

Are you a decorator by chance? sounds like you've done this a few times!!

😀

Far from it nowadays, but worked in a Resene colorshop many years ago as a student job.

And have painted *quite* a few times since then. From the lessons heard the hard way file:

1. It will take longer than you think. And you already think it will take longer than you think. Allow even more time.

2. There might never be time to do it right, but remember, you will have to find the time to do it over.

3. Drips will always be at eye level.

4. Yes, I know you can just squeeze in the last coat before dinner/bed, but if you do, you will stuff it up and end up doing another coat the next day anyway - see (3).

5. You will always miss at least one nail hole.

6. No matter how long you spend at Bunnings, you will always have forgotten or run out of something before the job is done.

7. Buy a rat tail cutting in brush. In fact, buy two (25 + 38 mm). Clean them properly and treat them right and they will pay back the investment in spades.

8. A coat hanger is the most useful painting tool there is. Go on, guess how.

Not to hijack thread, but i asked my painter......he could go all night on reasons....some quite creative!

Over and out

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David321

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#2453210 2-Apr-2020 17:46

Hi all,

Rather than start a new thread, I was hoping to get some advice about the other walls in my house. I have just peeled a little paper back in the other rooms and found it is fibreous plaster, would I still just slap on some pigmented sealer or would the broadwall surface prepbe the way to go for these walls?

Thanks,

_David_

mdf

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#2453229 2-Apr-2020 18:16

David321:
Hi all,

Rather than start a new thread, I was hoping to get some advice about the other walls in my house. I have just peeled a little paper back in the other rooms and found it is fibreous plaster, would I still just slap on some pigmented sealer or would the broadwall surface prepbe the way to go for these walls?

Thanks,

So long as it is in good condition (not powdery or flakey) and smooth enough for you to live with, sureseal is the way to go.

You do need to be a bit careful washing down fibrous plaster. You don't want to get it too wet, but you do need to get it clean. I think I've seen reference somewhere that some types of fibrous plaster used tallow as part of the manufacturing process and you don't want to paint over that. Haven't seen it myself though.

David321

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#2453251 2-Apr-2020 19:07

That's for your advice again, I have a feeling it may not be smooth enough based on the small area I have exposed, but ill find out more when its all off. If I find more imperfections like in the small area exposed I think ill need to have it smoothed out somehow, in that case would the broadwall prep be the way to go with a light sand after? To me it looks clean, maybe it just needs a dust down with a soft bristle broom?

As for the Tallow, I am not sure, can you tell from the picture?

Thanks again, your help is great.

_David_

mdf

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#2454080 3-Apr-2020 21:11

Are you sure that's fibrous plaster? Very hard to tell from one shot but it looks pretty smooth and there is a slight brownish spot. It might be skim coated gib?

In any event, if you need to do the whole wall, broadwall surface prep is an option. If it is just patches, it will be quicker and easier to use something like Selleys rapid filler.

Which apparently isn't an essential product, even though no more gaps is somehow.

You will almost certainly need to wash, not just dust down after peeling off the wallpaper. If it peels off easily (which it should) it will have wallpaper sizing onn it which you will need to get off. Might need sanding in bad spots.

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mdf

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#2454081 3-Apr-2020 21:12

I haven't seen it myself, but tallow will be a greasy or glossy section.

David321

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#2460436 13-Apr-2020 12:20

mdf:

Broadwall is typically only needed if you want a level 5 finish (i.e. ultra smooth or unusual requirements). Level 4 is pretty much a perfect finish for "normal" rooms - see https://www.gib.co.nz/homeowners/achieving-a-quality-finish/. It is more designed to finish/ultrasmooth something that is already pretty good. It won't (easily) fill big holes or dents on its own.

If you are applying over old gib, you will need to seal with Sureseal first (stops tannin leaching), then broadwall, then (most likely) 2 top coats.

Unless you are applying it with a wand and wingardium leviosa spell, Broadwall will almost certainly require at least a light sand before topcoating. This is essentially what it is designed for.

If it were me and wallpaper required stripping (assuming bare gib underneath):

1. Spot fill holes and worst imperfections.

Selleys rapidfilla is good (the coloured one is awesome). Sand back overfill as required

2. Full wall light sand

3. Wash with sugarsoap and rinse

4. One coat Sureseal pigmented sealer. Yes you have to used the oilbased, and yes it is a smelly pain and will require a long time before overcoating, but you will regret not using it if you don't and your topcoats discolour because of tannin leaching.

5. One coat Quickdry acrylic primer undercoat

5A (optional). Find the spots you failed to fill properly the first time. Refill, resand and spot prime. Repeat as often as desired.

6. Two top coats Resene Spacecote low sheen / flat in the colour of your choice

Always do your cutting in first, then go back and roll the rest using a low nap roller and laying off vertically.

@mdf Just a thought, would it be possible to "Find the spots you failed to fill properly the first time. Refill, resand" after the pigmented sealer rather than after the primer? that way I would only need to prime once. I figure the smaller holes would show up just as weel after a coat of pigmented sealer as they would after a coat of primer?

_David_

mdf

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#2460444 13-Apr-2020 12:32

David321: mdf Just a thought, would it be possible to "Find the spots you failed to fill properly the first time. Refill, resand" after the pigmented sealer rather than after the primer? that way I would only need to prime once. I figure the smaller holes would show up just as weel after a coat of pigmented sealer as they would after a coat of primer?

Ooh, now you're talking professional levels of skill! Yes, that is great if you can manage it. It's something that I have not yet mastered reliably, and I inevitably find things I have missed right before topcoating.

Sureseal is sort of off white (vague hint of green IMO) and Quickdry is white. You would be surprised at how much more obvious holes seem to be on white vs off white (well, that's my story and I'm sticking to it).

Ideally you don't want to put topcoat (i.e. coloured) paint directly over anything porous (at least where you can see it - tiny holes and hidden areas have a bit more leeway). Read the instructions on your filler whether it wants to be sealed (i.e. it is porous - usually plaster and cement based things) or primed/undercoated (pretty much everything else).

David321

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#2460541 13-Apr-2020 14:12

mdf:

David321: mdf Just a thought, would it be possible to "Find the spots you failed to fill properly the first time. Refill, resand" after the pigmented sealer rather than after the primer? that way I would only need to prime once. I figure the smaller holes would show up just as weel after a coat of pigmented sealer as they would after a coat of primer?

Ooh, now you're talking professional levels of skill! Yes, that is great if you can manage it. It's something that I have not yet mastered reliably, and I inevitably find things I have missed right before topcoating.

Sureseal is sort of off white (vague hint of green IMO) and Quickdry is white. You would be surprised at how much more obvious holes seem to be on white vs off white (well, that's my story and I'm sticking to it).

Ideally you don't want to put topcoat (i.e. coloured) paint directly over anything porous (at least where you can see it - tiny holes and hidden areas have a bit more leeway). Read the instructions on your filler whether it wants to be sealed (i.e. it is porous - usually plaster and cement based things) or primed/undercoated (pretty much everything else).

@mdf Thanks for the further info, ill have a crack at seeing if I can get all the holes filled up after the sureseal, it would save spot priming, but if I find I do miss some I could also fix them up after the undercoat shows them.

I was thinking of using the gib plus 4 plaster for filling holes and smoothing things out, it goes on quite nicely. Not sure if that needs to be sealed or undercoated though, hopefully and Resene quick dry would be suitable to cover it as I do not want to use oil based paints more than I have to.

_David_

mdf

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#2464038 17-Apr-2020 10:15

Short answer is I don't know for sure. I have never seen skimming compound used for spot filling. It is plaster based, therefore porous, therefore the orthodox answer is to seal rather than prime. Usually you would do the whole wall with it then seal. You might get away with just an undercoat if it is just spot areas, but I've never seen it tried so don't know.

If it were me, I would just use the right product for the job. Rapid Filler is great, comes in small tubs, and is designed for spot filling.

David321

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#2464072 17-Apr-2020 11:30

mdf:

Short answer is I don't know for sure. I have never seen skimming compound used for spot filling. It is plaster based, therefore porous, therefore the orthodox answer is to seal rather than prime. Usually you would do the whole wall with it then seal. You might get away with just an undercoat if it is just spot areas, but I've never seen it tried so don't know.

If it were me, I would just use the right product for the job. Rapid Filler is great, comes in small tubs, and is designed for spot filling.

@mdf thanks for all your info, I'm probably starting to be a bit of a pain but I think I have all the info I need now so thanks again! Now just to wait until I have finished painting my windows and level 2 to be imposed so I can visit a store for the supplies I need to do the walls

_David_

mdf

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#2464088 17-Apr-2020 12:00

Good luck!

For who only knows what reason:

EzyFill is an "essential product" available for delivery

Rapid Filler is not.

I wonder if test pots will be available for delivery / click and collect under alert level 3? Wall colour has always been something you shouldn't pick in-store anyway.

David321

485 posts

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#2464230 17-Apr-2020 14:24

mdf:

Good luck!

For who only knows what reason:

EzyFill is an "essential product" available for delivery

Rapid Filler is not.

I wonder if test pots will be available for delivery / click and collect under alert level 3? Wall colour has always been something you shouldn't pick in-store anyway.

Haha interesting, I think ill need more than 250g though, thats why I was thinking the plus 4 would be good as I know it comes in big buckets, I may need a bit, but ill find out what the walls are like when the paper is off I guess. If there is a lot of small holes like in the picture I posted before I might try the broad wall prep, rolling a whole wall with that and then pole sanding would be a lot easier and quicker (for me) than skimming the whole wall. Ill have to find out if Plus 4 needs an undercoat on it like Resene quickdry, or some other type of paint, hopefully the stores will be open by then so I can ask in store at Mitre 10

_David_

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