# Painting new plaster



## ProWallGuy (Oct 17, 2003)

It's been years since I have had to paint new plaster. I can't find any paperwork or notes on any job in the past that I have had to prime and paint new plaster. So, my question is this:

What would you recommend as a primer for new plaster? By new I mean it is a new plaster skimcoat, but has dried/cured for over 9 months. My first instinct would be an acrylic primer like BM FreshStart.

Any numbers as to material usage? I know it will be more porous than drywall, but how much? 50%? 100%? Anyone with a typical sq ft of coverage for new plaster?

Any help would be appreciated.


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## JMGP (Mar 29, 2005)

Your first instinct was right...

BM Fresh Start is perfect for that application...

As you already know there is a curring time... its definitely curred after 9 months...


I ussually get 250-300 sq ft per gallon.... (cut/roll) 1/2" roller cover... I apply it semi leberally...


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## chris n (Oct 14, 2003)

*Mr*

Your first instinct was right...

BM Fresh Start is perfect for that application...

As you already know there is a curring time... its definitely curred after 9 months...


I ussually get 250-300 sq ft per gallon.... (cut/roll) 1/2" roller cover... I apply it semi leberally...


Sounds right to me!


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## PlainPainter (Dec 29, 2004)

Don't prime with BM Freshstart!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I just finished a job with new veneer plaster, started the job 1 month after plaster was put up, primed with fresh start as per manufacturers specs, 30 days. When I was finished a month later - customer blue taped stuff to the walls - and then took it off - and the paint came off all the way down to the plaster!

I left a bathroom alone for 3 months on same plaster job - so plaster had 90 days to cure - did a test patch, as I didn't want the job to fail in the master bath. Painted a sq. ft. with the fresh start acrylic - came back a day later put on blue tape, ripped and it all came off. Primed with California's alkyd 222 primer - and absolutely nothing came off with a rip test.

You can prime plaster with oil based products after a 3 month cure. To be fair - I did another location - where the plaster was really trowelled well and tested the freshstart again - and it didn't come off. What is happening - is that plasterers come to a point where the plaster has been sitting on the walls for 10 or so minutes, still too early to wet trowel it smooth - but precisely the right time to 'draw up' the plaster, by forcing the trowel over the surface and compacting the plaster very tightly to the wall - this really gives the plaster it's final strength. Some guys are just skipping this step - because they can lay it on pretty neatly - and then just wet trowell it. The plaster will be softer and crumbly - and any latex primer won't have any sticking power - it just crumbles.

Do a test patch for yourself in several locations and then put blue masking tape firmly over the test patch a couple of days later - rip it off hard. Do the same with an alkyd primer test spot. Plasterers just haven't been doing their jobs lately - especially these days from screws to plaster at $1.50/sq.ft. I wouldn't even get out of bed!


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## PlainPainter (Dec 29, 2004)

here is a pic of the failure


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## Frankawitz (Jun 17, 2006)

I ran across a problem like this before and we whiched to using BM Block Filler I found it soaks into the plaster like oil and it bonds to it better then latex primers, and you don't have the clean up as with oil. It seems theres no place to take old trups other then the city, and they don't take a lot at any one time. gallon limit


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## boman47k (Oct 13, 2006)

PlainPainter said:


> here is a pic of the failure


Browsing some old post about plaster and found this. So what was the fix since the wall was already covered? No experience here with plaster at all. Oh, I reread and seen that you covered with alkyd primer over the Fresh Start.


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## mjay (Feb 2, 2006)

ProWallGuy said:


> It's been years since I have had to paint new plaster. I can't find any paperwork or notes on any job in the past that I have had to prime and paint new plaster. So, my question is this:
> 
> What would you recommend as a primer for new plaster? By new I mean it is a new plaster skimcoat, but has dried/cured for over 9 months. My first instinct would be an acrylic primer like BM FreshStart.
> 
> ...


read this
http://literature.usg.com/pdf/PM15.pdf


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## daArch (Jun 8, 2007)

Thanks mjay, that's a good sheet. It gives authority to what I've tried to explain many times. Now I can just point to it.

BTW, PlainPainter (and sorry to be so many months after the original post, but this is the first time I saw it) most adhesion problems as you describe are caused by surface dust that was not thoroughly tacked from wall surface. Too many think that a good vacuuming will suffice, it won't. 

And then we have the "painters" who claim the sprayer will blow the dust off as they paint the walls .... WRONG !!!

If you wiped the walls with a bare hand and saw absolutely no dust on your hand and still had the adhesion failure, then I am baffled by Acrylic Fresh Start not holding.


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## PlainPainter (Dec 29, 2004)

daArch - I soaked the walls with a mixture of 1-3/4 gallons of water to 1 quart of 5% acetic acid (i.e. white vinegar) and mopped the walls down. Prior to doing this, had you put your hands on the walls - they came out white as if putting your hands on a dusty chalkboard. After the walls dried the next day - there was no dust left whatsoever. I have done my own veneer plastering - and I wet trowel so much that after the walls dry - there is no dust leftover, except maybe near the bottom of the walls.

That all being said - the reason for the failure - is that the plasterer simply didn't trowel 'up' the plaster very well. To correct the failure I got out my putty knife and started chipping away the paint prior to applying some joint compound - what I noticed was that the plaster was excessively chalky and soft. And closer examination of the paint chips revealed a thin layer of plaster on the back sides of the paint. So in essence the primer stuck great - the plaster however didn't. I am finding this more and more these days. This plastering sub-contractor only charges his G.C. $25 per board for labor. I know in a day in age where everything has been cheapened - I still think this is ridiculous - and IMO gives the sub little incentive to do a quality job.

This however can be rectified by neutralizing the walls several times and waiting at least 3 months - and then using a slow dry alkyd interior enamel undercoater. I wait 3 months on my own plaster jobs, even with a latex primer - as the alkaline salts can still stain through - and in general have no faith anymore as to how quickly you can prime new plaster according to some manufacturers. I've tried following directions - and it hasn't worked. The old school methods are still king. And if you are wondering why you can't prime plaster walls with alkyd in a short time. Well plaster for the most part is Calcium hydroxide - which is a cousin to 'Lye' and when mixed with an oil - will form soap in a process called saponification. So plaster walls not only have to be dry to the touch - they have to be totally cured - and that only happens when they turn bright white - which takes time.


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## daArch (Jun 8, 2007)

PlainPainter,

I did not understand from your original post that the veneer plaster failed. I thought you stated that the Fresh Start only failed down to the plaster.

And yes, although most plaster is gypsum (Calcium sulfate), Diamond Veneer is <40% slaked lime (calcium hydroxide) which is highly alkaline and will raise hell with oil paint if not cured and neutralized (I'm surprised such a diluted acid does the trick for you - I like ammonia out of the bottle or muriatic acid :laughing If you run into this situation often enough, you should pick yourself up some pH testing materials. 

I had a vicious ceiling failure once by stupidly priming newly skimmed veneer with oil. I am now exceptionally shy of oil over any limed plaster. And let's not get into saponification on concrete basement floors :w00t: 

Latex will, by nature, have a higher tolerance to an alkaline surface. I also do not agree with manufacturer's recommendation that newly skimmed walls with ANY lime can be primed in twenty four hours. On the other hand, gypsum (aka plaster of paris) is neutral and can be painted as soon as dry. 

Another problem to watch out for is if the plasters have made any repairs with Hot Mud or JC. For some reason these on top of not thoroughly dried veneer also cause a bonding problem. AND some folks go so far as mixing hot mud with pre-mix JC. I have heard this puts the pH level off the meter - around 12 if I believe the rumors. 

But anyway, you sound like you have a good base of understanding.


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## PlainPainter (Dec 29, 2004)

DaArch - to be honest with you - I haven't done a ton of new plaster jobs. I followed manufacturers recomendations as to the amount of acid. What I am finding out - is that whatever I do, I tell other painters - and they raise their eyebrows and say they never had to do anything like that. All I know - without tons of prep - if you wait 3-4 months, a quality slow dry alkyd primer will recombine all the dust and form a hard surface and bond like heck. That's all I know - that in the end, oil primers save the day, if you wait sufficiently long enough. And as well - I don't go slapping tape on my walls and ripping it - so I don't really know, how well something has bonded. What should I do, construct mock walls with blueboard, veneer plaster, and try several products waiting different periods of time for plaster to dry? I don't know anybody that goes these lenghts - and lately my customer just don't appreciate what I do for them.


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## daArch (Jun 8, 2007)

PlainPainter,

Keep being cautious about the bonding issue. Us paperhangers are oft faced with poorly adhered paint and when wallpaper dries, it shrinks, and puts enough force on the wall to yank bad paint right off. WE appreciate you, even if the customers don't :thumbsup: But please do not "recombine all the dust" with the primer. 

Many of us paperhangers DO go around and slap tape on walls and rip it off - but first we even razor cut an X into the tape and into the paint. We need to know the paint is bonded properly. 

AND, I know just the guy who would (and has) gone to "these lengths" testing various paints and substrates.


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## PlainPainter (Dec 29, 2004)

I don't mind researching better methods - that's what I am all about. It's just folks have been totally price shopping. The lady I was working for - whom's walls are in the photo above with the ripped paint - she had her 'painter' do work for her for years, but fell 17 feet and couldn't complete the job. Anyways - as I was finishing the job - he was working on another, and told me and her that on the advice of paint store - painted 2 coats of Regal ben moore paint directly to fresh new plaster walls. Upon which, this total dumba$$ house wife looked at me and asked if it would have been better if I had done that. I literally wanted to go leaping out a window screaming at the top of my lungs. About painting in the dust - all my competition doesn't wash down fresh plaster walls. How do you go about charging people, how can you even begin to educate people - when there is an army of hacks out there who always say 'ah - you don't have to do that'. Kind of like when I reprime factory primed siding - there response - 'ah, you don't need to do that' - if I had a nickel for every job I lost where the competing contractor said that about my proposal.


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## daArch (Jun 8, 2007)

PlainPainter said:


> About painting in the dust - all my competition doesn't wash down fresh plaster walls. How do you go about charging people, how can you even begin to educate people - when there is an army of hacks out there who always say 'ah - you don't have to do that'.


How long does it take to dampen a microfiber towel (miftie) and wipe the walls? I can tack a room in like fifteen - thirty minutes. 

How to educate 'em?

Show 'em pictures of what will happen when they don't.

Show 'em PDCA standards.

Show 'em product directions. 

We all are, after all, salesmen. If you are in direct competition with lowballing hacks and make your sales pitch on that level, then no, you will NOT get the job. Part of your job is making them understand that quality doesn't cost, it PAYS.


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## regal (Oct 20, 2007)

..................................land shark........................................Aura....:whistling


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## ProWallGuy (Oct 17, 2003)

An update to my original post:

I wasn't awarded the job. Thanks anyways. :whistling


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## PlainPainter (Dec 29, 2004)

ahh- you didn't want it anyways. I literally hate being the first painter in on new work. Just get some hack to white wash everything - and I will come in 4-5 years later to repaint - that's the niche I like being in.


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## daArch (Jun 8, 2007)

ProWallGuy said:


> An update to my original post:
> 
> I wasn't awarded the job. Thanks anyways. :whistling


Just as well. You prolly wouldn't have been paid for that one either :laughing:


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