# Scraping off one texture, and replacing with "knockdown"



## OraarO

The rooms have painted acoustic (popcorn) texture now. I plan on scraping the tops off, as much as possible with one or two quick passes. Then skimming on up to two coats, applied horizontal and then vertical to minimize "skipping" over the remaining texture. Once that is sanded close to smooth, applying a knockdown texture by spraying thinned compound and then knocking it down. 

Question - Do I need to prime the skim coats so the knockdown texture doesn't "re-activate" the mud that was skimmed on?

Any other tips on doing a job like this? I have a bid I am comfortable with for this, but looking to save time/steps wherever possible.

Thanks.


----------



## JCardoza

Good luck! drywall remodel is tough enough for an experienced profesional... Nevermind someone who doesn't know the basics. I would prime the ceiling after scraping and before putting any mud on.


----------



## OraarO

Roger that.
What about after the skim coats? Before the knockdown coat?


----------



## Brockster

OraarO said:


> Roger that.
> What about after the skim coats? Before the knockdown coat?


Maybe you should be directing these questions to the DYI forum. :thumbsup:


----------



## OraarO

Um, excuse me?

Why is that? Isn't this forum for discussing issues like this?

What am I missing here?


----------



## Brockster

OraarO said:


> Um, excuse me?
> 
> Why is that? Isn't this forum for discussing issues like this?
> 
> What am I missing here?


A few years of drywall experience. :thumbsup:


----------



## OraarO

OH, Thanks Brockster

I thought this message board was to help other contractors, not rip for asking questions.

What's wrong with asking how some others would do a job, instead of just assuming the way I do work is the only way? I like how you and J assume that I have little or no experience. I have been painting for 12 years, performing many drywall repairs and texture matching. I recently started doing drywall and taping since contractors I work for like my work better than the other guys they have been hiring (the pro drywallers).

Anyone else have ideas for me?


----------



## Brockster

Fair enough. 

Was the popcorn painted??? If it is not then we used to just drape off all the walls with plastic and either use a very fine mist hose or a portable sprayer like the ones found in the garden section at the Home Depot and wet the acoustic down and wait a few minutes and scrape it all off.
Then just re-skim the seams and butt joints and touch up the edges and then spray your KD then prime and paint.:thumbsup:

If it was painted and it were me I'd run!!! Or just go out and rent the portacable with 80 grit and sand the heck out of it. Skim the whole ceiling with 90 then with regular mudd, sand KD, prime and paint.


----------



## OraarO

It is painted, and I would rather not create the dust issue with power sanding, so scraping and skimming is the route I have chosen, for better or worse.

I agree with your method for removing unpainted texture - that works great.


----------



## Brockster

The portacable has a hose that attaches to a shopvac and is virtually dustless.


----------



## OraarO

Awesome tip - I will definitely look into renting the portacable sander.


----------



## Brockster

They work great for quick removal of acoustic and for knocking the sand texture off the walls for a customer who wants a new texture. It's also one of my most valuable tools when I get called to a job that someone already started. You just have to know how to fix all the frayed paper from sanding all the mudd off!:brows:


----------



## fr8train

if you are worried about the thinned mud re-wetting the skim coat mud, use some hot mud for the skim coat, like easy sand or anyone of a few diff brands. once it's set and dry, it's dry. new mud on top of if doesn't affect it. Also if you get the right time easysand, say... 90 or more. You could get both skim coats done in a few hours, and maybe even get the job done in a day. depends on the size of the job, one room no prob, whole house might be a bit tough to pull off in a day . best of luck to ya


----------



## rettt

Try this - get a pump sprayer fill it with warm water and spray the ceiling in approx 5foot by 5 foot area with the warm water after wetting down the area let the water set into the ceiling texture for 5 to 10 minutes then , Use a sharp mud knife and slide the knife edge along the ceiling making sure to watch out for original bed joints .The texture should peel off very easly ! Dont jab the sheet rock with the mud knife and damage the original sheet rock paper bonded surface . Make sure to take a wet rag or wet sponge and wipe all residual texture from your sheet rock surface after you have done the first step . If you leave the fine powered mastic of the original texture on your old ceiling and dont do a wet wipe down to remove the residual powder you will have major problem with your new texture wanting to flake off when it is painted with a roller ! In short if you do not wipe the residue off after wet scraping your new texture will flake off while using a roller to paint !


----------



## Brockster

rettt said:


> Try this - get a pump sprayer fill it with warm water and


Over a painted surface?


----------



## rettt

*over a painted surface*



Brockster said:


> Over a painted surface?


 If the ceiling paint is flat paint it should work pretty easy with the warm water and the pump sprayer ! If the ceilings have semi gloss or high gloss paint , it will take much longer for the moisture of the water to absorb into the surface. Give it a try i do this all the time on residential homes which need ceilings restored to new condition , plus it keeps the dust completely out of the picture ! .


----------



## OraarO

Ok, I started this today, and it scraped off pretty well with a 5" knife. It was painted so there is some residual roughness left (more than just plain texture would have left. 

Thought of the day is: Would using a mud box as seen in this Youtube clip, be an efficient method to skimcoat the ceiling? I plan on applying two coats by hand (12" knife) now, so I would be OK doing two with the mud box, if it left an OK finish after two passes.






Thanks for any ideas. Other thoughts on applying skimcoats fairly quickly?

I still have approx. 1/2 of adjacent area remaining to scrape, skim and knockdown texture in next two days.


----------



## rettt

*about skim coating over the textured ceilings*

From past experiences --- :thumbdown:skim coating over the old texture ---moisture from your wet mud will cause areas in the old ceiling texture to release from the sheetrock causing what i call a drooping blister . Once the drooping blister along with all the other skim coat drys the drooping blister will be nothing more then a bubble . If anyone trys to use a paint roller on the blister it will crack and fall from the ceiling :wallbash:[ NOT TO MENTION YOU WILL SEE THE DROOPING BLISTER ]:stupid:! After this happens you will feel like cussing then come to the conclusion you will need to completely scrape the ceiling clean then use a wet spong to remove all of the old residue which will be in the form of a fine layer of white material from which you didnt get off while scraping the texture off ! IN SHORT DONT SKIM OVER OLD TEXTURE . It could mean youll be doing twice the work in the end when you try to pull a quick job of it :bangin:!


----------



## OraarO

Rhett -

I applied a coat of latex paint to all areas scraped, and that didn't bubble at all. I know there is the chance of existing to bubble, but seeing how it was painted once before, and now painted again, I am planning on skimming and not having much trouble. I have done ceilings like this a few times, and have not had any issues. Wish me luck.


Any thoughts on the mud box for skimming?


----------



## OraarO

Wow. $500 for one "skim box" and the pole?!
Holy shoot!

Guess I will hold off on that until I get a few more jobs lined up.


----------



## Sir Mixalot

*This stuff is so hard, you can't even scrape it.*

oraaro,
I recently skim coated a large ceiling that had vermiculite acustic texture . 2 coats(90 min. mud) opposite directions and 1 touch up coat(all purpose) then srayed w/ Knockdown.


----------



## OraarO

Looks pretty similar to what we are doing right now, Sir Mixalot. Nice work.


----------



## Brockster

:laughing:I wonder what the chance of spraying some thick mudd with a thick coat and smoothing it all out with a big knife, knock down paddle or skip trial knife and let it all dry out, sand and re-texture? I would much rather to mask off the walls than to have to apply several coats by hand. 
I think we are all going to be seeing a lot more of this shiftwork coming our way with new housing slowing down and people just wanting to remodel and update their homes.
Also, you think the unaggregated texture mud would be less prone to cracking than regular box mud?

ps. No, I'm not smoking pot, maybe I should be though with stupid ideas like this one...


----------



## OraarO

Brockster, that is exactly what I have been thinking about trying today....If I do, I will let you know how it turns out...


----------



## cooper

I removed some painted popcorn from the ceiling of my in-laws 'bonus room.' In the past I have used water and that is clearly the best, but really the best is getting someone else to do it... 

Anyways, I scraped the ceiling, dry, with a 10" knife, then sanded down what was left. Dust is irrelevant if you turn off relative cold air returns and mask the room tight. Doesn't take long, you're a painter, should just take a few minutes. I then daubed the ceilings with some semi-thick mud. A real ugly tight daub that covered the ceiling almost 100%. Then took my trusty 22" knock down knife and smoothed everything out. Then sanded that, skimmed with a hawk and trowel, then textured. 

No problems whatsoever... 

The daubing and knock down knife part can be down twice if you are not handy with a hawk and trowel. Almost any idiot can daub and knock something down smooth enough and sand to be ready for texture...


----------



## OraarO

Spraying the compound then wiping smooth with a 12" knife worked great! Sped the process up at least 4X!

If I did this again, I would let it set up a little more, then smooth it so it could be a little thicker, but I should be able to sand and then apply knockdown after this one coat.


----------



## Brockster

OraarO said:


> Spraying the compound then wiping smooth with a 12" knife worked great! Sped the process up at least 4X!
> 
> If I did this again, I would let it set up a little more, then smooth it so it could be a little thicker, but I should be able to sand and then apply knockdown after this one coat.


Fantastic OraarO! :thumbsup:What kind of compound did you end up using? I have a bedroom that I've put off since last summer that I started fixing yesterday. Hope to spray mudd on Saturday and OP Sunday.


----------



## OraarO

Brockster -

I used Plus3 Compound thinned quite a bit with water.
I spray with a small compressor - Marshall brand I think, and a hopper/gun setup.


----------



## KingOfDrywall

*Tools are costly*

there are places you can now rent them.......


----------



## A+ Texture LLC

Brockster said:


> Fantastic OraarO! :thumbsup:What kind of compound did you end up using? I have a bedroom that I've put off since last summer that I started fixing yesterday. Hope to spray mudd on Saturday and OP Sunday.


 Brockster, how did shooting and skimming go in that room? I've been thinkin about trying it as well.


----------



## eastex1963

Am I missing something here, or are my dates all f'ed up?


----------



## A+ Texture LLC

Its ok to bring up old threads.


----------



## eastex1963

Of course, I just thought my puter was on the blink. No worries.


----------



## A+ Texture LLC

Just tried the knockdown knife and texture thing to skim yesterday. Sprayed on knockdown pretty heavy and used I think a 24" bluesteel walboard knife, it worked well but this was just a test spot.


----------



## LightRock

*flat box skim...*

AS for using a box to skim: personally, i would skim with a 16" trowel and soft mud because the lines at the overlap, wheelmarks, air pockets etc you'd get running a ceiling with a box to skim it would negate the apparent benefit. the best investment to skim a ceiling would have to be a pair of stilts. half the cost of a box and 10 times as useful. drawback: deadly over loose drop cloths, oh and your 500.00 box needs a 400.00 pump to fill it 

I'd thought of doing the 'spray and wipe' skim, but i never have my texture sprayer along on skimming days. It is an idea I'll keep in reserve though


----------



## silverstilts

LightRock said:


> AS for using a box to skim: personally, i would skim with a 16" trowel and soft mud because the lines at the overlap, wheelmarks, air pockets etc you'd get running a ceiling with a box to skim it would negate the apparent benefit. the best investment to skim a ceiling would have to be a pair of stilts. half the cost of a box and 10 times as useful. drawback: deadly over loose drop cloths, oh and your 500.00 box needs a 400.00 pump to fill it
> 
> I'd thought of doing the 'spray and wipe' skim, but i never have my texture sprayer along on skimming days. It is an idea I'll keep in reserve though


 I don't think you know what you are talking about , sure it's nice to hand trowel out a skim coat but using a box is about 30 times faster and if you know how to run one you can do a better job than a hand finish that i will guarantee... i would like to see you hand trowel out without leaving any lap marks , only if u pull super tight you won't , the same for a box use the proper settings and don't run into wet mud , let it dry for a few minuets and go back over works perfect...... and as far as the investment of a pump and the boxes u have to have the right tools for the job... You wouldn't mix up mud with a stomper would you? i think you would have an electric drill for that .... I think most that don't want to invest in the proper tools are just plain cheap and are not worth a damn..... if i hired any carpenter to frame a house if he just showed up with a hammer and not a air gun i would know what kind of a carpenter he was .... come on get with the times , how many years have these tools been out ,,, way longer than you are older :blink:


----------



## Whitey97

^ agree 100%


----------



## LightRock

silverstilts said:


> I don't think you know what you are talking about , sure it's nice to hand trowel out a skim coat but using a box is about 30 times faster and if you know how to run one you can do a better job than a hand finish that i will guarantee... i would like to see you hand trowel out without leaving any lap marks, only if u pull super tight you won't , the same for a box use the proper settings and don't run into wet mud , let it dry for a few minuets and go back over works perfect...... and as far as the investment of a pump and the boxes u have to have the right tools for the job... You wouldn't mix up mud with a stomper would you? i think you would have an electric drill for that .... I think most that don't want to invest in the proper tools are just plain cheap and are not worth a damn..... if i hired any carpenter to frame a house if he just showed up with a hammer and not a air gun i would know what kind of a carpenter he was .... come on get with the times , how many years have these tools been out ,,, way longer than you are older :blink:


OK Here is what i am talking about: skimming over scraped texture. this was a response to the end of the first page, when Orarro wasn't sure if a box was the answer to his ceiling repair. How does that work out for you? I imagine scraped popcorn would give you endless runs with the box
I may someday try skimming with a box on a new ceiling, but i find that if the ceiling needs skimming , then i need the feedback from the trowel to get it perfect, since i only need to under critical light areas in the first place (sunshine straight down the wall) If I get a large volume of work that requires level 5 for spec, i would go to a mud sprayer like the heavy Graco's, but so far no one is paying a premium for that, mores the pity cause that is a toy i want


----------



## alltex

OraarO said:


> Roger that.
> What about after the skim coats? Before the knockdown coat?


 you dont have to prime it,just scrape it skimm
and touch it up and shoot it .dont let anyone talk you into doing more tha needed.knock down is very forgiving.Just watch when you knock it down.(not too soon.afterword prime and paint.


----------



## brdn_drywall

no kidding i don't know what kind of pistols/hoppers these guys are using but with a decent splatter and a good coverage spray you can hide a murder underneath there's no way you would have to finish to perfection with touch-ups for a knockdown. when you've been in this business long enough there's things you know you can get away with and the end result still looks like a million bucks!


----------



## MudMonkey

I skim coat by hand with a 12". Can do about 1000sq ft in about 2 hours. With a box you'll leave ridges.


----------



## Captain Drywall

dont sand, do not sand, refrain from sanding please. flat paint will sofen up quit nice with water and scrape right off. Enamale paint, ive done a few. I scrape to the to the rock, dry, with a three inch putty knife. do not gouge the paper. scrape it clean. dont sand. finish the joint and nails like any other skim coat. if you caulk the angles it will be real clean looking. If you use spray texture for your knock down it will come out better . Even unagregated texture mud has some ruffness to it that knocks down easier. dont use all purpose unless you just can't get texture.


----------



## igorson

OraarO said:


> The rooms have painted acoustic (popcorn) texture now. I plan on scraping the tops off, as much as possible with one or two quick passes. Then skimming on up to two coats, applied horizontal and then vertical to minimize "skipping" over the remaining texture. Once that is sanded close to smooth, applying a knockdown texture by spraying thinned compound and then knocking it down.
> 
> Question - Do I need to prime the skim coats so the knockdown texture doesn't "re-activate" the mud that was skimmed on?
> 
> Any other tips on doing a job like this? I have a bid I am comfortable with for this, but looking to save time/steps wherever possible.
> 
> Thanks.


I think you will do better if you _prime_ before _skim coat_ otherwise if you prime after _knockdown _or skim coat you would have to _paint the ceiling_. So you save your money and time on _painting ceiling_ :thumbup:
http://1drywall.com/textures.html


----------

