| Author |
Message |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 397
Registered: 07-2002
| | Posted on Friday, December 17, 2010 - 02:08 pm: |    |
there is the stuff the the painters sell and stuff the epoxy floor people sell - let's leave the fiber glass mats or chopped material aside for the moment.
What is the REAL difference; scrubbability, and a bunch of other properties? (e.g. hardness, impact resistance ....)
or is the real differnce chemistry, build thickness or just the sales person? |
Richard Hird (Unregistered Guest)
Unregistered guest
| | Posted on Friday, December 17, 2010 - 08:46 pm: | |
To me, I write mostly Architectural Specs and occasionally specifications for chemical, waste treatment and industrial facilities.
Paint: Epoxy paint is a high gloss coating that is excellent for washdown (not high temperature steam cleaning). It has only limited testing for resistance to chemicals. Typically it is a one part polyamide or other low cost polymer with a dispersion vehical; water or solvent.
Coatings:
Industrial coatings are single or two part polymers selected for specific chemical or temperture environments found in industrial or waste treament applications. They are tested for specific environments. At one time environments were listed in catalogues for each product, but the manufacturer's now need information as to the chemicals temperature and duration (splash, spillage or imersion) of the exposure included in the specifications.
A third category are industrial floor coatings subject to impact loading, again specifics of the exposure need to be specified.
Coatings can be thick or thin, cheap polymers or exotic phenolics, reinforced or unreinforced, decorative or bland. An epoxy paint may do just fine for some industrial applications, however I have seen such substitutions fail in a matter of weeks and the difference in cost between the two is in multiple dollars per square foot; say $2.00 to $10.00, so you need to make your coating specifications clear as to the exposure, or specify a product that has been tested for that exposure. |
Jim Sliff
Senior Member
Username: jim_sliff
Post Number: 15
Registered: 08-2010
| | Posted on Friday, January 28, 2011 - 02:27 am: | |
I have been on the manufacturing, sales, contractor and spec end where epoxy systems are involved.
Technically and legally there is no difference between epoxy paint and epoxy coating...because the difference is not technical, it's just semantics.
There are no industry standards controlling the use of words like "paint", coating", or even modified versions like "industrial coating". A manufacturer can use any term he wants...but the label description will normally govern the VOC classification - at least in most cases.
Paint, coating, protective film, decorative membrane, opaque varnish, water-based single-component epoxy, epoxy-fortified acrylic, corrosion-resistant acrylic primer....
Each one of those "descriptions" is used in so many different ways that each is absolutely worthless in trying to define a specific material.
And don't even get me started on gloss level descriptions...ah, I can't help it - "satin", "eggshell", "low sheen", "soft gloss", "velvet sheen", "semi flat" (no kidding - I've seen that one) - after 35 years I STILL don't know the difference...because there isn't any...or there is. It depends on who you talk to.
I'm going to go find some Tylenol now. The caplets. Or tablets. I forget.... |
John Regener, AIA, CCS, CCCA, CSI, SCIP
Senior Member
Username: john_regener
Post Number: 502
Registered: 04-2002
| | Posted on Friday, January 28, 2011 - 05:32 pm: | |
Re: sheen
For shortform specs, would it be appropriate to simplify sheen to "shiny" and "dull"?
And all paint, of course, would have to be "green". |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Friday, January 28, 2011 - 05:51 pm: | |
The Master Painters Institute (MPI) has a very good discussion of gloss and sheen and references ASTM D 523 (see http://paintinfo.com/mpi/approved/sheen.htm). While most paint labels are OK for "flat" and "high gloss", the "velvet," "eggshell," and "satin" designation, and even "semigloss", fall prey to marketing hocus pocus. Using the MPI designations gives one an objective means of actually measuring sheen rather than read off the can.
Most of my clients want as close to flat as they can get for all surfaces (speaking of "standard" paint products). This makes the uneven drywall less noticable. I don't mind that for ceilings, but walls need a higher sheen. A paint with a higher sheen will usually last longer when subjected to cleaning. I can usually get a "low sheen" (MPI Gloss Level 2 or 3) accepted for walls. I usually strongly recommend semigloss for metal and wood trim, especially for "high touch" areas such as doors and frames. I also recommend this for restroom wall and ceiling surfaces. There are a number of designers who have very strong feelings about this so at the end of the day, I have to defer to their "professional expertise."
One of the school districts in this area is insisting on semi-gloss for all surfaces.
In place of "standard" latex paints or alkyds, there is a class of higher performing acrylics that I have begun to specify for high-touch surfaces like doors, frames, and handrails, usually in a high sheen if permitted. |
Jim Sliff
Senior Member
Username: jim_sliff
Post Number: 16
Registered: 08-2010
| | Posted on Friday, January 28, 2011 - 09:29 pm: | |
John - You pared things down to perfection.
Peter - In all seriousness I am very happy with what I've seen come out of the MPI; initially many folks who had been involved one way or another with the paint industry for many years had reservations. Many of the manufacturers reps I talk to were initially crying foul because "their" product line was SO different, or management had a perception of skyrocketing costs.
Instead it's brought quite a bit of stability - and quashed the marketing ploy of some manufacturers, who in the past tried to have their internal ASTM-method test results appear to be "standards".
But the gloss issue *is* still muddy. There have been attempts by PDCA and some manufacturers' organizations to standardize the low-to-semigloss arena, but there always seem to be a few companies that will go their own way. Attempts at categorizing fixed degrees of gloss just never seem to reach a consensus. When something like "Gloss range 10-20 on a 60-degree meter" shows up in a spec or in a finishing schedule the reality is the actual product could be just about anything that's not dead flat and not high gloss; in 35+ years I have seen a gloss meter on a jobsite once - and it was a demo of a gloss meter for lab use! |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 400
Registered: 07-2002
| | Posted on Saturday, January 29, 2011 - 10:59 am: | |
One of my Tnemec Reps (Jenny Senner) figures stating values for particular ASTMS and having that be the basis of "special coating" may be the ticket.
vs
paint which is color and gloss and maybe scrubability BUT ASTM values dont play as great a role.
short list of ASTMs
Corrosion Resistance ASTM B 117
Adhesion ASTM D 4541
Humidity ASTM D 4585:
Pencil Hardness ASTM D 3363:
Impact Resistance ASTM D 2794:
Moisture Vapor Transmission ASTM D1653:
QUV Exposure ASTM D 4587:
Abrasion Resistance ASTM D 4060: |
Sheldon Wolfe
Senior Member
Username: sheldon_wolfe
Post Number: 462
Registered: 01-2003
| | Posted on Saturday, January 29, 2011 - 11:20 am: | |
ASTM has different standards for testing some properties, and all manufacturers don't use the same standards. Even if they do use the same standards, we need to know more than the stated properties.
As noted in "Missing Standards", we need to have a rational basis for setting minimum properties, something other than what is found in the manufacturer's literature - when they bother to give them. |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 401
Registered: 07-2002
| | Posted on Saturday, January 29, 2011 - 11:28 am: | |
I agree, I'm not done yet and I'm sure I'll get frustrated trying to get apples to apples and let's don't even talk about chemical resistance |
Jim Sliff
Senior Member
Username: jim_sliff
Post Number: 18
Registered: 08-2010
| | Posted on Saturday, January 29, 2011 - 12:20 pm: | |
Actually, every one of those ASTM test methods is used and results just as important for "paint" (whatever that is) as they are for "special coatings coatings" (whatever they are).
Flat vinyl-acrylic wall paints can have wide variances in abrasion resistance and pencil hardness for example; paint (as opposed to what we usually call "industrial coatings or high-performance coatings") has been in existence for thousands of years as evidenced by ancient cave paintings (don't we wish some of the stuff we buy today would last as long!).
"Durability" is a word often used, but one really more applicable to the substrate than the coating (although the coating formula has some effect). A stable, relatively neutral, dry substrate like rock is a good surface for paint - hence the survival of historical cave art. Other surviving ancient coatings on flexible surfaces are usually more of a "dye" or "stain" made from an organic penetrating material than a "coating" (Shroud of Turin, anyone?)
You can make a simple water-based paint using water (duh...), Elmer's glue (or Titebond...or equal...I don't want to make this a proprietary product), a few drops of dishwashing soap (which is a "wetting agent" that helps the film coalesce and apply smoothly) and...dirt. Take a mortar and pestle and grind the dirt into a fine powder, then blend it together with the other goodies - ta-da! Acrylic Paint. And if you used a glue that was based on a 100% acrylic resin (and enough dirt), it's most likely going to dry resulting in the following:
100% acrylic low-sheen paint.
It's going to stick as well as most commercial paints. Depending on the source of your dirt, it may have better or worse corrosion resistance than a commercial water-based metal primer. QUV results will primarily depend on the dirt - some elements fade more when exposed to sunlight than others.
It's probably a tan color (having done this in the past as part of technical training sessions, my victims...errr, students...ended up with tan "paint" from most dirt sources). But if you got your "dirt" from the black sand beach on the northern tip of Kona in Hawaii, it'd be gray. It would also have outstanding QUV test results compared to most commercial gray "paint".
But would you specify it?
It'd have lousy corrosion resistance, and if the dirt percentage (the largest part of the "volume solids") was very high it would have terrible impact resistance and adhesion, as it would not compare well to commerecial paints using a common flexibility test, ASTM D522 - 93a(2008). It would be quite brittle - and that test plus a couple of others are quite critical for ANY film-forming liquid coating, be it "paint" or "special coating".
In reality even a "simple" flat wall paint is FAR more complicated and will have dozens of components.
This simple example demonstrates how easy it is to make "paint", but how much flexibility there is in formulation - and how use of some components may compromise performance in one or more areas.
You can't separate "paint" and "special coatings" and say the quality of the latter can be determined by ASTM test method results but the quality of the former does NOT depend on those same test methods.
The additional dilemma of using ASTM test method results as "standards" is - WHO is going to determine what the baseline result is for each test? The ASTM numbers on paint data sheets are the manufacturer's own test results (or results from an outside lab). They are NOT standards set by ASTM.
Yet many Architects, Engineers, painting contractors and paint/coating salespeople are led to believe that some particular company's ASTM test results are actually ASTM "standards". Specs are written around companies' products that require submitted (or substituted) products to "meet the ASTM test results of the specified product".
From a technical standpoint, that's flat wrong. There is no "right" or "wrong" for most ASTM test results - there are levels (pencil hardness is one that comes to mind) but a higher or lower number is only important if the paint/coating's specific application requires test results to be within a certain range for proper performance - but again, only in THAT application. When used on a different surface or in a different place, a test result range that was acceptable one place can be totally unacceptable in another.
An entire st of test results has to be carefully balanced to produce a product that does "something" - functions as a wall finish, performs as a ferrous metal primer in a marine environment, is used as a temporary coating, can be applied underwater (yes, those exist) - the paint chemist's job is to look at all the variables and assemble the most cost-effective group for a desired result.
There are many raw material vendors, many guide formulations for each type of paint/coating and many different approaches to the manufacturing of a single generic product. A variance of one test result may be totally irrelevent - and that test not important in the performance of a particular coating, hence rarely performed - , but "loaded" on a manufacturer's product data sheet to eliminate competition. Other manufacturers don't perform the test and won't have ANY results.
And we have a rejected submittal for an absolutely invalid reason.
It gets even better when the specification requires "certified test results from an independent laboratory" with a submittal or request for substitution; then dog-piled with "...matching ASTM test results on file in the (specifying entity's) office".
So not only do non-specified manufacturers have to have tests performed at potentially high cost (plus many of the tests take months to perform, prohibiting a submittal or substitution simply on the basis of time) but they may have to match test results that they can't see, might be irrelevant, and they don't even know WHICH tests would need to be performed.
This is why I particularly like the MPI's approach of determining a reasonable baseline and having all parties know what to expect.
Hopefully MPI will expand their depth into the industrial coatings arena or a similar organization will begin to develop the same type of system.
I hope this didn't get anyone off track - primarily I wanted to show that ASTM tests are important for ALL paints/coatings, but that one manufacturer's results cannot be used as a "standard" without very careful consideration of how submittals and substitutions can be fairly handled. |
Jim Sliff
Senior Member
Username: jim_sliff
Post Number: 19
Registered: 08-2010
| | Posted on Saturday, January 29, 2011 - 01:28 pm: | |
Oops - forgot one thing I wanted to clear up regarding Richard's first post. I know my preceding post was entirely too lengthy but there was no other way to clearly demonstrate some of the issues. However, there are a couple more really critical ones when it comes to trying to define that wet stuff someone puts on some surface for some reason (please bear with me for the first few paragraphs...):
1. Epoxy paints are not necessarily "glossy", and most will be just about dead flat after 6-12 months exposure to UV. This does not sacrifice the protective qualities...just the aesthetics (and the clothes of anyone who rubs against it!)
2. Many epoxy paints are excellent for high-temperature steam cleaning. Temperature resistance and low permeability are key qualities of many epoxy paints.
3. There are piles of chemical resistance data for epoxy paints. As they are often used for secondary containment chemical resistance information is critical. I can't think of a single major manufacturer that does not have some type of chemical resistance chart, table or guide either as part of a product data sheet or in a systems guide.
4. Most epoxy paints are plural-component polyamide or polyamine-based, with many having NO "vehicle" (i.e. they are 100% solids - put on 10 mils wet and you get 10 mils dry).
5. As far as "Coatings"...errrr, wait a sec - what's the difference between "epoxy paint" and "epoxy coating"?
6. Nothing.
7. That's the problem with such descriptions - one person's "paint" is another person's "coating". There is no "line in the sand". There's no specific technical definition. "Coatings" salespeople often like to use the phrase "It ain't paint" - except it is.
Definition of PAINT
1: the action of painting : something produced by painting
2: makeup; especially : a cosmetic to add color
3a (1) : a mixture of a pigment and a suitable liquid to form a closely adherent coating when spread on a surface in a thin coat (2) : the pigment used in this mixture especially when in the form of a cake <a box of paints>
3b : an applied coating of paint
(Merriam-Webster online)
...except how does one define "thin"? In the "paint" world "thin" might be .5 mils to one person while it's 3 mils to another and 15 to another.
Coating:
An industrial coating is a paint or coating defined by its protective, rather than its aesthetic properties, although it can provide both. (wikipedia)
Coatings provide protection against the elements.
(random search result)
But is it thick? And what does "industrial" REALLY mean? WHAT exactly are the "aesthetic properties"? Intentionally-aged, peeling and bad looking paint that also protects a surface (say at an amusement park attraction) is...what? Has it "failed" - if not, has a newly-applied normal coating that looks similar also not failed? How do you compare it performance-wise to a new-looking...uhhh..."fluid applied coating"?
Last kicker - the label a Specifier puts on a material in a Specification is a legal description as far as air quality regulations are concerned. That means if we specify an industrial coating for an application that does not precisely fit the legal air-quality related description of an application we may be in violation of the law (in reality often are). Also, any Specification or Finish Schedule "label" defines the VOC limits of the paint/coating that can be used...and sometimes what's specified does not legally exist (in the 80's this was really common - less so now, but a very real problem if we specify industrial coatings in the wrong place.).
As The Stones said, You Can't Always Get What You Want. Or in a sort-of parallel-universe example, if my old buddy Dave Major is still around he'll remember this from a seminar about 25 years ago:
"That's not broccoli - it's cauliflower or equal..." |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Sunday, January 30, 2011 - 12:13 pm: | |
I share the difficulties that Marc and Sheldon have with high-performance coatings and flooring materials. I have ASTM data for a class of products which are supposed to be equivalent or at least similar, except the references are different and when they are the same, the values are somewhat different. And then I am told that manufacturers can tweak the formulas to get to any values they want (think about Jim Sliff's basic "paint" formula and how it would come out if you varied the proportions of the components (or maybe if the "dirt" you used was from SE Texas silty-clayey "gumbo" rather than good New England dirt).
What I want is not necessarily the highest values possible, but the values that are just good enough. I don't want the cheapest stuff, but I usually don't need the most expensive stuff either.
OK, I have values for adhesion, pencil hardness, corrosion resistance, abrasion reisistance, etc. Which of these are really important for a particular application (say a school corridor wall vs. a ceiling in the same corridor). I know that a resinous flooring system in a kitchen needs to have a different set of chemical resistance properties than one used in an elementary school restroom. I am probably going to need better resistance to heat as well as say indentation. But what should those values be?
And then there are those that give compression strength for the aggregates in the floor system but not compression strength for the whole system.
I would suspect that most of us are mostly at the mercy of the product rep's honesty and understanding of the product line, appropriate application, and understanding of the project parameters. It is so tempting to select the most expensive stuff because all of the values are much higher than any other product.
The problem seems to me to be more critical for the flooring systems followed by the high performance coatings followed by paint, if for no other reason than the cost differences are more between the "best stuff" and the "cheap stuff." |
Jim Sliff
Senior Member
Username: jim_sliff
Post Number: 20
Registered: 08-2010
| | Posted on Monday, January 31, 2011 - 01:41 pm: | |
"I would suspect that most of us are mostly at the mercy of the product rep's honesty and understanding of the product line, appropriate application, and understanding of the project parameters. It is so tempting to select the most expensive stuff because all of the values are much higher than any other product."
That's been pretty much the case (and by the way, clay IS often used in paint formulas).
That's why I have started using MPI's output as a starting point - it's not perfect and you can't just grab a product a specify it without investigation, but at least they narrow the field and generally weed out the "duds" (or the lame manufacturers never submit products to them). I have the advantage having spent my first couple of decades working for manufacturers, but that can provide and extremely narrow, focused range of knowledge if you don't learn to "think generically" and gather information outside your employers' self-produced "technical data".
"Paint", Coatings" and just about any fluid-applied system including some that are more commonly found in Division 7 can be very difficult to specify due to the lack of firmly-entrenched standards. Manufacturing is in a constant state of flux due to air quality and other environmental regulations. It's almost a full-time job just keeping current on what seem to be simple products.
That's why there are consultants out there who will review paint, coating and related Specs on a generic, preferred-brand(s) or proprietary basis. They try to keep up-to-speed...and it's a lot of work with changes here or there almost daily. |
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