Knochdown Wall Finishing

RichWei

Ok Ok ! I know I am supposed to be an expert!!
I have a need to refinish a sixty year old house that has plastered walls. I have repaired all the flaws and now want to do a knock down finish to cover any slight imperfections. Our local rent-all has the sprayer but it seams no
one can explain just how it is done or what materials to use.
I was wondering if lowering the pressure to produce a globby matte would be the answer?

Dick

Mike Finley

I do rooms and repairs not whole houses so I use a hand held hopper like a spraying mantis and a compressor. Medium hole on the gun, 50psi on the compressor and mix the consistancy of runny pan cake batter, feathering the trigger as I go. One thing I avoid is using drywall mud, I always use powdered texture compound. It's way stickier than mud.

You shoot it and let it set up a bit and then use a knock down knife on it or a knock down squeegy. The key is knowing when to knock it down, when it's perfect it won't drag when you knock it down. Do some expirementing on a wall, you can wipe it off and try again and again.

back@it

I'm no expert either on that type of texture but I'd think you could roll a heavy set of 'mud', stomp it with a stomp brush, then come back over it when ready and flatten down? Just a thought!

I've actually intended to try this on a wall in my own house just to see if it would work...

send_it_all

Finley's method is the way to do it. It's pretty easy. As he said...spray texture on with a hopper, or rent a texture machine. wait for sheen to be gone, lightly touch with trowel or drywall knife. Practice on a scrap sheet of drywall first to get desired texture. You'll pick it up fast.

DelW

I've got the Graco Tex Spray 1250 and have used it on a few bigger jobs. The hopper guns are great for smaller jobs but if its more than a room using the hopper gun gets heavy.
Finley is dead on with regards to the dry time(usually about 10-15 min)and using non-aggreated texture material. One other point, make sure you prime before and after you texture.

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Mike Finley

One other thing, always shoot the ceiling last. I shoot the walls first, always starting at the bottoms and working up to the top and then the ceiling last. The ceiling will dry so fast it isn't funny. If you shoot it first, it will be setting up before you finish the walls.

One other tip, I found works well for doing patches or even entire walls where you are shooting over new dryall and old, is to use a spray bottle and wet the new drywall mud areas down before you spray, if not the new mud will suck the moisture out of the texture and when you go to knock it down you will be able to see the differences. Spraying down the newer drywall mud areas allows a pretty good match.

send_it_all

Mike, I'm guessing that is why DelW recommends priming before the texture. I do that and it help even the absorbtion rate so you get an even texture.

Mike Finley

Yeah, no doubt priming it first would take care of that, good idea if you've got the time for sure.

Tmrrptr

Here in CA we sometimes use prep coat before texturing. Good stuff.

Don't rent a hopper...

Marshalltown is abt $75 and any twin tank cheapo compressor will do.
Optimal is a compressor that will supply 9cfm @ 60 psi...

Powder bags of wall tex is stickier and better, but I use mostly 3 1/2 gal buckets of pre-mixed Redi-spray product on most jobs, or get rid of the rest of my taping mud, if used on the job. mud is mud. Sometimes I'll mix 'em all together to use up stuff.

I always do the lid first, and start walls at the top.

There's actually a lot to learn about texturing, but if you're on your own project, no one can say your efforts are wrong!

Wetness of the mud, nozzle used on the hopper, air pressure, Dwell time before knockdown, size of broadknife, and pressure used on the knife all play a factor in the texture achieved. I've got half a dozen different knives I may use for a knockdown.

I almost always use the biggest nozzle tip as my hopper has a limiting adjustment. If doing lids, the 30% adapter is a help.

Any hopper gets far too heavy. My favorite is a smaller import hopper, but I've got to refill it too frequently... gives me a break!

Here in CA the trend is going away from a machine sprayed knockdown finish. A Mission Finish is becoming popular now. It's less intense than a skip trowel finish, wetter, and more mud, random indisgressions.

Me? I like a double crow's foot, applied not too busy, and knocked down fairly wet. Interesting leafy pattern excellent for a faux finish or rag-off.
r

Nuvisiondecor01

You want to use a popcorn sprayer. Use the Sheetrock plus 3 All purpose joint Compound in 5 gal. bucket. You can get it at Menards. Water it down to the point where it will easily flow through but not drip. Spray it on the wall and give it a few minutes to set up. Use a plastic wall scraper. Sand it down so it is smooth and doesn't leave scratches. From the top left corner holding it at an angle. Smoothe the mud in a slow motion. I usually go from left to right and top to bottom. In a diagional motion. It may take a few times to get it right. Then let it dry overnight. Next, with a used sanding sponge. (Make sure it's dull or it will scratch.) Lightly sand the entire wall. That's it. Other than removing the dusty debre. Paint right over it. Two coats are necessary.

localtradesman

AS an inside guy...with hundreds of jobs under my belt...I can tell you that Spraying with UGC mud is absolutely fine. Mix the mud to a slightly wet mixture with water. I spray what I can knock down and then continue on. I use a knock down knife....sometimes a trowel depending on the situation. I do not prime the walls as you are spraying mud on the walls....same product as your joints ect. Maybe someone can tell me why they prime BEFORE they spray??? I do wipe down my trowel or knockdown knife constantly as to keep the crumbs down. Sponge works fine. One think you really need to get is a Radius 360 sanding pole...it is the best product on the planet in my eyes. It's new, wish they would have had it long ago. Anyway, I would not recommend you winging it on a customer. Takes some skill to do a perfect job. I would not use a portable compressure either. Rent a unit...it is much better for constant air flow. Most smaller compressors cannot keep up and this will cause air flow to go up and down...not good at all. Consistancy is very important when applying your mud. I do the ceilings first and partial on the walls. I use stilts to knock down the ceiling. It does dry quick though. This is why the stilts are critical to any drywall man.

localtradesman

Drywall mud sprayed over existing paint will not absorb very quick at all...and this makes the job even more critical for the drying time to knock down. Been there many times and it isn't fun. Remodel jobs have been my specialty all my years in business, I have never been in the miserable world of Generals that squeeze you for a penny.

wheeling

I am doing knockdown in huge Hotels and my super is telling me to not sand the walls after the wallpaper has been taken down. what should I do, because I know better?

SLSTech

2007 & not even adding anything to the topic...

Try this, go post an intro & search the threads

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Workaholic

lol yep it is an old thread.
I agree with Del, once you have used a tex sprayer that hopper gun will seem like a PITA

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Sean

nEighter

and if I can add anything.. before you paint, run your hand or a sponge across the area that is/was textured.. small area hand, larger areas a sponge.. this will knock off the small crumbles that make a finished job look like crud. It also slightly takes the edge off the set up knockdown.

DISCLAIMER: don't do that until it is either dry or in the lighter grey stage (almost dry)