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Why backroll?

75K views 26 replies 13 participants last post by  ArthurM 
#1 ·
I have read that when spraying latex wall/ceiling paint that someone should follow behind and "backroll" the paint. Is backrolling necessary and what does it do? Is it necessary to backroll the primer also? Is backrolling just a quick once over with the roller? Just need to know before I screw something up and have to redo it. Thanks for your input.
 
#3 ·
When you backroll, procedurally it's nothing more than just following up behind the sprayer with a roller on a frame I like to use 1/2" nap roller. The difference obviously is that the paint is already on the surface, and all you have to do is run the roller through it. But don't be mistaken by it's ease...you still have to have good technique meaning don't leave lines or roller marks, not too heavy of a touch, etc.

Back rolling helps to even out the spray coat applied product whether it be primer or paint, and if it's drywall primer in new construction it helps to lay down the drywall paper fuzz. FWIW I back roll all sprayed paint, I think it leaves a more uniform appearance.
 
#4 ·
I don't spray paint, but I've been told the reason for backrolling is that a sprayer simply doesn't force the primer into intimate contact with the porous surface of the paper or joint compound the way a brush or roller does. You need the wet primer to be "pressed" against the porous surface for good adhesion.

Apparantly, the problems you get if you don't backroll are related to poor adhesion cuz just spraying the primer on doesn't press it against the substrate with sufficient force to get it to properly "wet" the surface of the drywall paper or joint compound for proper adhesion.
 
#6 ·
Whatever you do DO NOT SPRAY THE PRIMER. I am in the process of removing paint and sprayed on primer from several rooms (walls and ceilings!) The primer was sprayed on and now the paint and primer comes off in sheets. The primer just didn't adhere. It was a HUGE mistake, so take it from someone who has a massive problem on her hands, not to mention $ down the drain. Timesaving sounds great sometimes, but stay away from the temptation. It's not worth it in the end.
DorothyOlive
 
#10 ·
never found a need to backroll

I have sprayed hundreds of new homes over the years and have never backrolled save a few times because the builder requested it. The most important thing to remember when spraying paint is that some paints are better for spraying than others when it comes to new drywall. While spraying can cause the drywall to "fuzz" up this is do to the sanding of the drywall compound prior to painting, If you pole sand all surfaces between first and second coat you will eliminate virtually all "fuzz". Sounds like alot however any able bodied person should be able to sand all walls and ceilings in a standard house in about 2 hours. If you are lucky enough to follow a real good drywaller that sponges all his joints , no need to sand. also depending on the paint that is used you can do touch up with a brush and it will blend in, whereas using the backroll technique you usually have to touch up with a roller. As for spraying a primer, unless you are just calling your first coat a primer than o.k but as for using a seperate paint for your first coat and then applying a finish coat, a waste of time in most situations unless trying to go from oil to latex or a few other situations than obviously you would need a primer. But why not save time and money and just put on two heavy coats of your finish paint
 
#11 ·
Back rolloing

Think of a sprayer as a machine gun. It shoot micro drops of paint on the wall, and with the pressure behind the machine it will have "overspray". These micro drops do not hit ever bit of surface you are trying to spray. So the darker the color, the more you will see through the paint. So on the finish coat you do need to backroll, this will fill all the voids the sprayer can not fill. Duane @ Color Wheel Paints and Coatings, Gainesville Florida.
 
#12 · (Edited)
Think of a sprayer as a machine gun. It shoot micro drops of paint on the wall, and with the pressure behind the machine it will have "overspray". These micro drops do not hit ever bit of surface you are trying to spray. So the darker the color, the more you will see through the paint.
So how come I can cover a surface completely with paint from a can of spray paint then? In fact, sometimes if I'm not careful, I spray too much and the paint sags on the surface I'm painting before it dries, making an ugly mess. So, my spray paint is sagging on the surface I'm painting, and you're telling me I still haven't covered the surface completely with paint. I need to back roll to spread the paint over all the unpainted areas? What gives?

So on the finish coat you do need to backroll, this will fill all the voids the sprayer can not fill.
Why don't they backroll when spray painting cars then?

When I've seen cars being spray painted, the spray seems to cover the surface completely with NO unpainted areas (regardless of how small they are). I don't see why you'd get unpainted areas on drywall if you don't get them when spray painting a car.

Please explain where my thinking is wrong on this. How come I can spray paint something myself with a can of spray paint and cover it completely with paint, and a guy spray painting a car can do the same, and they can spray varnish onto furniture and cover it completely, but a professional painter spraying latex paint can't do that so you need some monkey to follow him with a roller to backroll the paint to cover the drywall entirely. Huh? Does not compute. Does not compute. Does not compute. Does not compute.

What am I missing here? If everyone else can do it, including me, why can't a professional painter spray latex paint on a wall and cover the wall completely?
 
#13 ·
"Does not compute..."

Nestor, backrolling seems to be a preferred method used by some professional painters, others not. And I'm sure they have their reasons...but does it have to make sense to you in order for them to do it?

Backrolling a spray-painted car, on the other hand, makes no sense whatsoever and you know why. So why call everyone out on this?
 
#14 ·
Yeah, Carlisle, I guess I went a bit overboard on that one. I was pretty plastered when I posted that, so that's probably why.

Things don't have to make sense to me before I can accept that other people do them. 1.3 billion people using chopsticks to eat rice is a perfect example.

In this case, I just wanted the poster who used the machine gun analogy for a paint sprayer to question his explanation that the purpose of backrolling is to ensure that the surface to be painted is completely covered with paint. I thought if he realized that other things that get spray painted get covered completely with paint, it would occur to him that the purpose of backrolling wasn't to get that 100% coverage.

In my kitchen I have two refridgerators. One contains food while the other contains two stainless steel cylinders and a cast steel cylinder. The cast steel cylinder contains liquid CO2 at a pressure of about 700 psi, and the stainless steel cylinders contain home made beer. That fridge allows me to have cool carbonated beer on tap 24/7. As long as my posts occasionally sound like I'm bouncing off the walls in a rubber room, you can be sure that both fridges are working properly. :laughing:
 
#15 ·
LOL...:thumbsup: gotcha...:laughing:
 
#16 ·
backrolling

The advice I gave you "machine gun" is a simple look at a small amount. The reason when u spray paint out of a can and it sags is because you are moving to slow with the can and you may be to close. I have been selling paint and sprayers since 1994, and thought with my years in the business would help you. If you take your "spray can" and spray it proper you will also have to pass the same areas twice and sometime more. That is backspraying, just like backrolling. You ensure the area is covered. Good luck with all you do.:thumbsup:
 
#17 ·
Duane:

I should probably apologize if I offended you or anyone in here. That's not my way. I feel it's best if everyone, whether they have years of experience or are relatively new to DIY, feel free to voice their opinions. It's not always experience that leads to a solution. Sometimes beginner's luck works like a charm, too. I'm planning to join the professional bull riding circuit this spring. I hope to do well as I have nearly 50 years of beginners luck saved up.

Just like in every other forum, the most important thing is for everyone to feel free to voice their opinion. In this way, all the possibilities get brought to the original poster's attention, and he might see one that best explains his problem. Sorry if I made you feel ill at ease for expressing your opinion. I make my own beer, and I drank too deeply from the trough last night.
 
#21 ·
Well my 2cents. First off, you will always find thosebwho swear by and defend to the death the way they do things, backroll. Not backroll. What size tip to use. The ones who say theirs is the only way are ignorant. As my grandpa would say,"there's more than one way to skin a cat."

That said, there are some good reasons to backroll and in my opinion it is not always necessary.

I should start by saying I am a licensed contractor.

In general, bqckrolling is used to help give paint proper adhesion, we all know that.

But when is it necessary? The surface you are planning to apply paint to and how it was prepared are the deciding factor. Oh! And the person doing to painting as well! Having hired many "painters" who say they know how to spray, backrolling is used to even out an inexperienced painters work.

The poster who used the machine gun anaolgy is correct in one respect. The small particles fly out of he gun. But incorrect on Thor lack of uniformity. The droplets have a trajectory and can miss areas with a high tecture, just like a shadow cast from the sun. So backrolling is used to get all the missed areas.

The other reason is because paint is thick. Surfaces with cracks need backrolling to help push the paint in. The paint wants to just sit on top. You want to get it in all those cracks though to help keep out moisture and give the paint a good finger hold.

Over most surfaces I do not backroll. It is unecessary. Clean, dry, lightly textured. You don't need it. You need to have a good command of your spray gun, and make sure you have even coverage. But as for adhesion. It is more likely the old paint undernieth will release first.

Which is a good possible reason that woman had paint falling off. There are times when the solvents in primers, which are much stronger than in the paint, will penetrate the old paint. Eating away the bond the old paint had with it's surface.

So. To backroll or not to backroll. The quick answer.

It depends.
 
#22 ·
Hi DuckLand,
My experience with the "paint falling off":( actually had nothing to do with spraying or back rolling. I agree with you wholeheartedly that it "all depends". The problem I had was the plaster, it has a high ph 13+ and a latex primer was not recommended. I finally found the solution to the overwhelming disaster by actually looking up the plaster brand on line and reading the types (not brands) of paint that would adhere to this plaster surface. I explained everything I learned on my thread here on DIY Chatroom which is titled "sprayed on Kilz 2 latex primer and now paint is soft and peeling" or something like that:wink:. In the end I learned a few valuable lessons:1. Educate yourself about any new applications and keep record of the brand (ex. plaster) for future reference. Manufacturers of the product are most likely more knowlegable about what types of primer/paint and the best method of application so do some homework, don't expect that the plasterers and/or painters know what's best 2.There are so many products available and staying with the products that you have used in the past may not work on different surfaces. 3.Ask for help and listen to and consider ALL suggestions for an answer to your problem. You may learn a lot in the process. 4. Painting IS an art and a vocation, every ounce of experience is a value in itself ... and 5. LAST BUT NOT LEAST!!! This chatroom and everyones input helped me solve a catastrophic problem. I haven't finished the repairs but everything I've repainted so far is still on the walls. I am most thankful for all the different suggestions and how they guided me in a direction I would never have gone on my own. YOU ALL ROCK!...now if I could just get everyone to help me finish the rest of the rooms...:whistling2: LOL
Needless to say, varying opinions/techniques may not just be bullheaded Know-it-allness... like you said "it depends". How true:yes:
Dorothyolive
 
#23 ·
Spraying and backrolling

First of all if you have drywall paper showing through with fuzz from over sanding then you have a poor substrate right from the get go lol. A proper drywall finish should have at least a level 3 to a level 5 drywall finish.......... period. If not it needs to be sealed properly with a penetrating product to "lock" the surface down. I have been in this business longer than airless sprayers, amazing straight line paint brushes, ......Oh and lets not forget the "one coat covers all" paint. lmao, I know that if you dont first get all the dust off your walls then all the paint does is lie on the surface and will not bond to anything hence the sheeting effect




Does this look familiar? Anyway as you can tell I have ran across this more than once and its all because of inexperience and improper wall preperations. The infamous backrolling scenario came about years ago as a way to determine the fine line between whos job it was to get the drywall dust off the walls before the painting was to proceed. When drywall finishers bid these new conctruction jobs out they determined that it wasnt part of their contract to "dust the walls" (why not? they put it there?) and the painting contractors said that it wasnt part of their contract to do it either because they were suppose to be left with a sound substrate to work with. So some bone head came up with the quick fix idea that if you backrolled the primer after it was sprayed the wet paint would pick up the drywall dust and mix it with the paint by rewetting it thus making it a sound substrate again WRONG! lmao
As far as the sprayer leaving little doplets of paint, called atomizing, is true but has nothing to do with this issue and thats not the reason for backrolling,.... geeeezzz ...some paint store reps kill me lmao, these guys need to leave the field stuff to us and stay in the stores,..... anyway ......backrolling is done on cementous substrates such as concrete block , stucco, and generally rough surfaces using an 1 1/4" nap roller of good quality to push the paint into the surface to fill the surface and if not done correctly or with a cheap product will cause whats called "pinholing" in which case you must apply another coat of paint to fill the surface for a proper job and must drymill out to specifications in order for a warrenty to be valid by the paint manufacturer. Just ask our sales rep over hear he can tell you th millage because I know he has had to use this as a defense against color matching issues lol, .............Im scaring him right now and I know hes cussing me out about now but I am telling you all the truth here.
If the drywall dust is not removed then the paint just lies on a bed of dust which isnt sticking to anything but the dust. You literally have to shop vac the walls to get all the dust off and then seal the walls with something that will penetrate the drywall mud. The only remedy that I have have found was to use a very thin oil primer or sealer to lock the surface down
Boy I sure miss the old days when everything was lime plaster or "hardcoat" life as a painter was much simpler then, but because of the costs of plaster applications builders, architects, and the higher ups thought that using drywall applications were more cost effective and cheaper to use and through the years a very important trade in the construction business had been flitered out to almost a non existant artform. I have seen some of the best hardcoaters in my day but now its impossible to find one anymore because it truly is a dying art do to progress
Backrolling interior walls with your finish paint is a must because of touch up problems in the "production painting" end of new construction AND if your using a contractors grade paint ( the irony of that term kills me) I dont care what you do a cheap paint doesnt touch up most the time anyway lol even some the expensive stuff is horrible for touch up ......I can see 90% of all of you knodding your heads while reading this..... thats why I have a following as I do because I do know what Im talking about and not afraid to tell people lol but thats not say that im always right either
Oh one more thing the droplet thing hes talking about is called a "holiday" which is why you spray two coats and not try to get away with just one which is called "blow and go" in the industry which is what many of the production and track homes are that were built after 2000 2001 and finally till the end of the housing boom and even creeped into alot of the most expensive homes as well......Trust me I know, because Im the one they call to fix it,...... If they would have chosen guys like us in the first place they wouldnt be paying us four times more to fix it......funny how things come full circle

Peace!
 
#24 ·
Dorothy Glad for you

I glad you found the problem and your absolutely right! The PH factor in a hardcoat is very important to meter before priming and a "hot" primer is needed. I know you have a mess there and my heart goes out to you. Make sure you use a primer thats can handle the ph. On exteriors we use to have to hose down the exterior walls to get the ph down before we could even prime. which will bring it down 4or 5 points. But in your case you are not able to do this. You may try and sponge the walls down with water to bring it down but dont saturate it. On hardcoat I use a couple different products but the one I use the most was Ben Moores 066 unpigmented, I think its good for a ph up to a 13 but I would check with the rep to make sure, I know its an exterior product but its one that I would trust and providing that you get all the Kilz2 off you should be fine but I would stil sponge the walls down first and check your ph with a ph pencil and distilled water because tap water has to many chemicals in it for the pencil to give you a proper read and remember the first color you see is the one you go buy. Green is go and yellow is better.....

Peace! http://www.art-faux.com
 
#25 ·
The photos!!! OMG!

Hi Arthur!
LOL those photos of the "peelable" paint are VERY familiar! Although it's a shame to see that someone else had the same disaster occur, it's also a relief to know that it wasn't MY fault. I had been questioning my technique, my choices in products and even the tools I used. WHEW! At least I know now that I'm not the complete dolt I thought I was. Something about the photo scares me though. LOL The paint color is very similar to the color I used in one of the rooms where I think I have no problem. That room had different plaster and primer... hopefully all is okay.
Funny how you should mention the "hardcoat" of years gone by. I recently helped a friend remove wallpaper from a home she had just purchased. The house was built mid 60s to mid 70s. I marveled at the quality of the plaster surface and its durability. Wow! what I wouldn't give to have THOSE walls. They are pristine! Master craftsmanship there! A sadly lost art :(.
Thanks for your reply I chuckeled a lot while reading it (a smile right about now is worth a million, so thanks, thanks , thanks). Including that photo was muchly appreciated.
dorothyolive
 
#26 ·
Why Backroll??

Nestor....with or without the liquids in the fridge :laughing: common sense and logic tell me that the difference in spray painting a car or walls/ceiling is the difference in the materials, non-porous on the car vs porous on the walls/ceilings. Metal is slick and non-porous, walls/ceilings are dry and porous. And there is a definite difference in the paint chemicals/compounds between the two. So go have another one and think about it :) some more. The light bulb might come on, lol. :thumbup:
The auto paint or spray paint is so different than house paints. Different viscosity, weight and textures. My brother does auto/body work, so I've seen a lot of the paint over the years. Seems to me the backrolling would be the way to go to leave the smoothest finish, but listen to the pros. They've helped me greatly on here. :thumbsup: Good luck with your job and have one for me.
 
#27 ·
Backspraying? what is that?

Thanks dorothy I like to help when I can, believe me in my 30 plus years I have seen alot of wild things go on with paint and the majority of the time it has to do with the initial prep

BUT.....this a new one I have never heard of Duane .....

Backspraying? lmao .....

I think the term your reaching for is called "Backpriming" :wink: which has nothing to do with what your referring to

Backpriming is what should be done to all cornice and trim work during the building or remodleing process and should be acclimated before installment to ensure of a 100% primed surface instead of just priming the side that gets painted.

How many of you here have problems or know of someone who has cracking on corners and miters of doors , casings , crown moldings, and any where else there is wood? yes base boards too.....

show of hands please........come on ....dont be shy.......uh huh .....everybody with a new home right?

Well guess what folks? its because nothing is backprimed and the carpenters didnt glue and nail their miters either. Its called production work in the construction industry which is what alot of you got for quality from the cheap labor that ran most of us experienced quality Americans out of business.......

What happens is before the painter even gets into the house to paint it everything goes in doors, crown, casings,baseboards...everything...lickem'and stickem', blow and go, I know all the lingo.

Anyway after the Acclimation (sp) process, (cooling of the home) because this wood is not properly sealed, it twists, warps, shrinks, bends and basiclly takes on a whole new meaning to the word reincarnation lol

First it starts with one little crack in the corner of the crown molding, waaaayyyy up in those twenty foot trayed ceilings or maybe even in your 12 foot ceilings

Go ahead take a look around Ill wait.......:whistling2:

Uh oh,

I see some worried looks and i dont blame you because now you have to recaulk and fix all these areas before you can repaint all your trim work, but the worse part of it is its only going to crack again but eventually over time it will become less apparent, But the thing is you also have to repaint the walls also because now you have fresh caulk on the walls and most likely the paint they left over for you to touch up with most likely wont match anyway...
 
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