# Applying paint at the recommended thickness



## Jmayspaint (Mar 26, 2013)

I have been painting professionally for twenty years, but only in the past five years or so have I been really trying to apply paint by the recommendations on the spec sheets. For most interior latex paints the specs call for a 4mill coat. After a lot of experimenting and some changes to application techniques I can now get a 4mill coat on without runs or sags. This is the most important improvement I have ever made. My local colleagues don't do this. I have never even met another painter who checks mills on residential work. I'm thinking this lack of standard must be a local thing. 4 mills is a lot of paint to put on at one time, but if you can do it the results are amazing. Most painters I work with( including myself until recently) put paint on at maybe 2 mills. Surely proper application thickness is one of the most important things in painting, and most pro painters pay attention to it? I'm really interested to hear other painters who check there mills


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## South-FL-Painter (Jan 17, 2012)

Only when applying roofing coatings.


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## ewingpainting.net (Jun 2, 2008)

josh, that's cool you practice that. I never checked mills on interior surfaces. but I typically lay a coating on as heavy as I can without sags or runs anyway. exteriors I am more cautious and have been known to check the mills


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## CApainter (Jun 29, 2007)

For coating performance and protection value, the manufacturer recommended mil thickness is important when painting over bare substrates like concrete, steel, or wood. This is where an initial protective barrier is critical. However, on repaints, where an existing coating is already providing the base coat and barrier build, I don't concern myself with film build too much, unless I've prepped aggressively.

As much as paint build is important, particularly with 28% SBV WB paint for example, it is still important not to apply too thick, and to second coat too soon, before the initial coat has formed a proper paint film through the vehicle evaporation process.


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## mustangmike3789 (Jun 11, 2011)

As an inspector, i check wft and dft on a daily basis as it is a requirement on all of the jobs that i am on. As capainter said, depending on sbv, some paints can be applied to minimum wft without runs or sags but others will require multiple coats to achieve the same minimum thickness. I just started working with fast clad hb from sw which states that it can be applied at 12 - 19 wft but it may require multiple coats to do so. The product is only 42% sbv and you will be lucky to get 10 - 12 mils wft without runs depending on the color or tint base used. Deep tint bases for red paints sometimes require 16 or more ounces per gallon of paint so it makes it more difficult to build these colors without runs or pigment floating due to the low amount of resin to pigment volume. Some high solids epoxy paints 70 -100% sbv can achieve 10 - 20 mils with a single pass without runs due to the low amount of solvents or thinners introduced.


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## Wolfgang (Nov 16, 2008)

ewingpainting.net said:


> josh, that's cool you practice that. I never checked mills on interior surfaces. but I typically lay a coating on as heavy as I can without sags or runs anyway. exteriors I am more cautious and have been known to check the mills


Just wondering, since you have a lot of experience with elastomerics, if you check the mils those jobs? Do you test one area or a few?


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## ewingpainting.net (Jun 2, 2008)

wolf, on a big job I will. typical repaints no, but will check the dft from time to time. 

ca I agree with you, I was thinking of standard paints. of course some products require different methods. good point! instead of just being worried about the mills, consider all the manufacturer recommendations a good practice.


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## NACE (May 16, 2008)

I agree with Mustang and CA. If there is a spec that specifies WFT and DFT I'm checking it and usually it's on steel with a prep standard applied. Residential and Commercial generally the applicator knows how far a brand will go on a given surface and spread rate is determined not by SBV but by experience. Architects will sometimes spec mils on large residential or commercial jobs but I still go by sq ft per gallon for a given brand based on experience on a given surface. No need for a Tooke Guage on the plaster walls of Gearge Soros house in Manhattan despite the architects specifying DFT. Not the right tool for plaster, but you get my drift. The GW and Brooklyn Bridges are a different story.


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## painterman (Jun 2, 2007)

To the original poster...what tool are you using to check mil thickness


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## mustangmike3789 (Jun 11, 2011)

painterman said:


> To the original poster...what tool are you using to check mil thickness


A simple wet film gauge can be used to determine wet film thickness. Dry film can be checked with a type 1 gauge/ banana gauge or a type 2 guage that works on electronic magnetic pull or eddy current. Ultrasonic gauges can be used over non magnetic substrates such as stainless steel or concrete. I don't see the tooke gauge used to often unless there is a failure analysis to read the film thickness of previously applied coatings.
The frequency of testing is normally written in the job specification. If it is not in the spec, sspc has a written set of standards under paint application called PA-2 to determine the frequency of measurments on steel substrates.


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## Jmayspaint (Mar 26, 2013)

I use a wet mill gauge. It looks like a credit card with teeth. You can usually get one at SW for free. The point to me was not as much to get technical on a simple interior reprint, but just as a guideline. I have seen so many painters( myself included until recent years) having the classic problems with latex, like flashing,dragging and poor coverage. Because the tendency is to put it on too thin. Even mid grade latex can cover great and smooth out to a beautiful finish if you put enough of it on. I'm doing the forth coat of epoxy on a warehouse floor today. Checking mills is certainly more important on something like that, or structural steel, but it has helped me in all areas


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## ARC (Nov 30, 2011)

I don't measure mils other than by eye and by feel, but I do agree that a reasonably thick coat yields great results in many situations. 

I think a closely related consideration is the dry time of the coating... since a thicker coat allows longer dry time, and therefore a more even finish can be had when rolling or brushing. I am a believer in the "all at once" rolling technique, i.e. no back rolling, and this lends itself to that.


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## Jmayspaint (Mar 26, 2013)

ARC said:


> I don't measure mils other than by eye and by feel, but I do agree that a reasonably thick coat yields great results in many situations.
> 
> I think a closely related consideration is the dry time of the coating... since a thicker coat allows longer dry time, and therefore a more even finish can be had when rolling or brushing. I am a believer in the "all at once" rolling technique, i.e. no back rolling, and this lends itself to that.


Yes, I try to get the paint on thickly and evenly with as little tooling as possible, and as fast as possible. With certain paints, when they are drying they can look crazy, and then they will flow out at the end and look awesome. It's totally different than the way I used to paint, trying to tool the paint smooth, rolling the sh$t out of it. The more you tool latex the worse it looks.


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## Paradigmzz (May 5, 2010)

joshmays1976 said:


> Yes, I try to get the paint on thickly and evenly with as little tooling as possible, and as fast as possible. With certain paints, when they are drying they can look crazy, and then they will flow out at the end and look awesome. It's totally different than the way I used to paint, trying to tool the paint smooth, rolling the sh$t out of it. The more you tool latex the worse it looks.


Post a video. All this talk is redundant. If you are reinventing the wheel, show us, don't keep hammering a point that makes little sense without visual evidence.


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## TJ Paint (Jun 18, 2009)

Paradigmzz said:


> Post a video. All this talk is redundant. If you are reinventing the wheel, show us, don't keep hammering a point that makes little sense without visual evidence.


I think you might have to pay him first.


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## RCP (Apr 18, 2007)

Thought of this thread when i saw this.


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## jack pauhl (Nov 10, 2008)

ewingpainting.net said:


> josh, that's cool you practice that. I never checked mills on interior surfaces. but I typically lay a coating on as heavy as I can without sags or runs anyway. exteriors I am more cautious and have been known to check the mills


I'm with Gabe. Thats pretty much how I do it. All it takes is an afternoon with some paint, some samples and a gage. Just lay some paint down as you would and check your work. Its likely whatever habit you have today applying paints has a mil average attached to it. Using a gage will let you know what that is.

I do 10 mil draw downs and hang them on a wall so i can get an idea what a product will do. My application 'habit' norm is close to 10 mil and I typically lay off anywhere between 5-7 maybe 8 depending on product. Its really not something I gage anymore. I know where I am simply by how it feels and I am sure many of you do it the same way. Just becomes natural for us.


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## ReNt A PaInTeR (Dec 28, 2008)

jack pauhl said:


> I'm with Gabe. Thats pretty much how I do it. All it takes is an afternoon with some paint, some samples and a gage. Just lay some paint down as you would and check your work. Its likely whatever habit you have today applying paints has a mil average attached to it. Using a gage will let you know what that is.
> 
> I do 10 mil draw downs and hang them on a wall so i can get an idea what a product will do. My application 'habit' norm is close to 10 mil and I typically lay off anywhere between 5-7 maybe 8 depending on product. Its really not something I gage anymore. I know where I am simply by how it feels and I am sure many of you do it the same way. Just becomes natural for us.


Good to see back Jack! :thumbup:


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## Jmayspaint (Mar 26, 2013)

jack pauhl said:


> I'm with Gabe. Thats pretty much how I do it. All it takes is an afternoon with some paint, some samples and a gage. Just lay some paint down as you would and check your work. Its likely whatever habit you have today applying paints has a mil average attached to it. Using a gage will let you know what that is.
> 
> I do 10 mil draw downs and hang them on a wall so i can get an idea what a product will do. My application 'habit' norm is close to 10 mil and I typically lay off anywhere between 5-7 maybe 8 depending on product. Its really not something I gage anymore. I know where I am simply by how it feels and I am sure many of you do it the same way. Just becomes natural for us.


Are you meaning you apply standard latex wall / trim paint that thickly? 

Tried a 1/2 inch, 50% lambs wool cover the other day. 
My apprentice has gotten good at rolling at 4-5mil with a 3/8 microfiber. turned her loose with the 1/2LW (a 14 inch too) to roll some hall ways. 
After the first hall I checked a few spots and it was 6-8 mil.
She was only getting 200 ft per gallon though. 
I liked the look o it, but had to back her off a little to come closer to the footage I estimated. (300)


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