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-   -   Enamel vs Urethane vs Polyurethane???? (http://www.hotrodders.com/forum/enamel-vs-urethane-vs-polyurethane-43949.html)

MARTINSR 07-22-2004 08:18 AM

Enamel vs Urethane vs Polyurethane????
 
Barry, you responded to a post of mine on orange peel with the comment...

"Martin,
You are right to question the mils.
This is a major factor with acrylic urethanes BUT NOT a factor with Polyurethanes.
Now don't confuse what I said with "cross-linked poly's=(enamel with a polyurethane hardener) Not same ball game."

Ok, what in the heck is the difference? I understand the "poly" means "Many". My understanding is that simply means "Many" urethane resins are used. How does this make a difference in how it is "cross linked". I thought any product with a hardener is going to "cross link", even epoxy will "Cross link", creating a new compound. That is what I thought at least.

Acrylic urethane, Polyurethane, "just" Urethane. These names seem to be put on just about anything and it seems it is the marketing of the product more than the chemical make up that dictates it. They seem to be interchangable sometimes. Well, not the "Polyurethane". But for instance, S-W has a high end SS product for fleets it is called an "Acrylic Urethane". This EXACT same product is sold with a different label on the can in a "value line" and is labeled simply "Urethane". The "Polyurethanes" are mixed off the same mixing bank as the base coats (which are simply acrylic enamel) with only a change in drier (if used) and "mixing clear" or "binder" and they are magically transformed into a "polyurethane". This includes the PPG "Concept" we were talking about.

PLEASE clear this up for all of us, what makes the difference between a Polyurethane and an Acrylic Urethane? And why does it cure different?

I know there is a difference but I sware, the names are thrown around by marketing and make no sense.

BarryK 07-22-2004 08:56 AM

The terms are misused on a regular bases.
Unfortunately there are no Urethane police.
Your ex-company is one of the very worst for playing games with the name.
In short a true polyurethane resin will have good flexibility and NEVER need a flex agent.
In short if you look at Acrylic urethane under a microscope you see the resin structure looks like a ladder (in short terms)
A polyurethane will look like an over reinforced (many times) house Gable.
Activation of Polyurethane will be 3:1, 2:1 or 1:1 as it takes more isocyanate's to lock the product down where an acrylic urethane can be activated all day long with a 4:1 mix.

Polyurethanes usually end up with a 2 pencil hardness witch is softer than an acrylic urethane, so this gives it much more stone chip resistance and a lot better adhesion.
Polyurethanes will be much more resistance to harsh chemicals and that is why on jets its a requirement.
Up until 8-9 years ago Polyurethanes were very hard to buff and to lay with out orange peel was almost impossible except where you ran it.
This has all changed as there is no longer a spraying difference
between the resin systems, if the company is using newer resins.

A well made Polyurethane will also have more clarity(cleaner gloss) than an acrylic and most true with excess coats such as
custom painting.
Another benefit is is easier to make a polyurethane to buff good even 30-60 days later where a lot of clears after 3-5 days forget it on the buffing. Not all polyurethanes are easy to buff 30 days after painting but it can be done if the company wants to put the effort into it. This is very important for restoration as were painting the car in pieces off the frame and it may be 60 days before the car is put together and can be wet-sanded and buffed.

MARTINSR 07-22-2004 11:21 PM

Ok, you have cleared up a lot on the linking, if I am understanding what you are saying that is. Tell me if I am wrong.

A polyurethane has "many" resins, thus many different molecules to link, right? I see a urethane as let's say black and white marbles covering the floor with strings going from one to another. Then polyurethane as black, white, red and blue marbles covering the floor with strings going from every white one to every other color and every red one to every other color and so on. Am I on the right track?

Ok, if I am on the right track that is great. But now with the confusion. You say that a urethane would have a 4:1 mixing ratio with hardener and a polyurethane would have a 2:1, 3:1 or 1:1 ratio, or do you mean the ratio with iso molecules?

Because if you mean with hardener, S-W acrylic urethanes use a 3:1 ratio. And by the way, you mentioned PPG "Concept" SS in that other thread implying it was a polyurethane. But it is advertised as a acyrlic urethane, not a poly.
If you are talking about the mixing ratio with hardener, how do you know how much Isos are in said hardener by wieght or volume or what ever? Couldn't a pint of hardener from one brand or product line have a different amount of isos than another pint from another line or brand?

Ok, next question, I mentioned this in the first post. Many of these products like IMRON and S-W Genisis and PPG Delta have dedicated mixing banks. The toners and hardeners are not used with any other system. This makes sense, as far as the name it is called actually being believable. Genisis is called a "true" acrylic urethane while IMRON as I remember is a polyurethane and Delta, I don't remember, I think it is just refered to as a "urethane". Anyway, ok, they have a dedicated system.

What about something like Chromaone, Concept, or TecONE they are mixed off a mixing bank which also provides the base coats, interior colors, (with S-W a number of different urethane SS) and even acrylic enamel on some of them. All these systems use ALL the same toners for all the "qualities". All of these systems are basically, acrylic enamel systems! Yet with a different mixing clear or "drier" or something they magically become an "Acrylic urethane"?
How?

BarryK 07-23-2004 05:00 AM

Quote:

Originally posted by MARTINSR
OK, you have cleared up a lot on the linking, if I am understanding what you are saying that is. Tell me if I am wrong.

A polyurethane has "many" resins, thus many different molecules to link, right? I see a urethane as let's say black and white marbles covering the floor with strings going from one to another. Then polyurethane as black, white, red and blue marbles covering the floor with strings going from every white one to every other color and every red one to every other color and so on. Am I on the right track?
+++++++++++++++++++++++++++++++++++++++++++++
I have herd this taught this way before. It works, I just like the ladder.
++++++++++++++++++++++++++++++++++++++++=====

OK, if I am on the right track that is great. But now with the confusion. You say that a urethane would have a 4:1 mixing ratio with hardener and a polyurethane would have a 2:1, 3:1 or 1:1 ratio, or do you mean the ratio with ISO molecules?
*********************************************
The NOCS are matched in each product so you can have a quart of activator for a product be it any ratio, and one quart may be 33% Iso's in that quart can, the next system may be 75% iSO'S.
*************************************************

Because if you mean with hardener, S-W acrylic urethanes use a 3:1 ratio. And by the way, you mentioned PPG "Concept" SS in that other thread implying it was a polyurethane. But it is advertised as a acrylic urethane, not a poly.
************************************************
It is an acrylic, I was referring to the clear and Primer as far as the poly's.
**********************************************

Ok, next question, I mentioned this in the first post. Many of these products like IMRON and S-W Genisis and PPG Delta have dedicated mixing banks. The toners and hardeners are not used with any other system. This makes sense, as far as the name it is called actually being believable. Genisis is called a "true" acrylic urethane while IMRON as I remember is a polyurethane and Delta, I don't remember, I think it is just referred to as a "urethane". Anyway, ok, they have a dedicated system.

What about something like Chromaone, Concept, or TecONE they are mixed off a mixing bank which also provides the base coats, interior colors, (with S-W a number of different urethane SS) and even acrylic enamel on some of them. All these systems use ALL the same toners for all the "qualities". All of these systems are basically, acrylic enamel systems! Yet with a different mixing clear or "drier" or something they magically become an "Acrylic urethane"?
How?

************************************************** **
All of them start out as Polyester (lacquer) or Enamel. and than taken from there as far as if blender is in the tints or added later,
THATS where the magic is in the blender of course if its mixed with the tints to start with your more limited. One of the most unique systems was the UTech system. You may have seen it system was pure tint. so off one system you could make laquer or polyurethane!!

MARTINSR 07-23-2004 08:30 AM

So you can add resins with the "mixing clear" to the toners in the formula and make a true polyurethane because you are simply adding different resin making it "poly"?

That makes a lot of sense and clears up that for me. If a certain resin is in the toners already, that may not be possible if I understand correctly. The toners on that UTech system for instance are a "Virgin" toner with no particular direction in technology. You add the resins to make it a lacquer, enamel or Polyurethane, right?

Is this like the S-W "Dimension" line? On the same bank you make synthetic enamel, base coat, acrylic enamel, and SS urethane. I found it to be a pretty good system. They have some problems with slow cure times but over all I thought it was pretty user friendly.

But back to the mixing ratios, they really don't mean a whole lot when it comes to determining if they are poly or just urethane because of the different amounts of iso's that "could" be in the hardener right?

Hey Barry, thank you very much for "learning me" on this subject. It really clears up a lot I never got into when I was repping.

BarryK 07-23-2004 10:00 AM

[QUOTE]Originally posted by MARTINSR
[B]So you can add resins with the "mixing clear" to the toners in the formula and make a true polyurethane because you are simply adding different resin making it "poly"?
*************************************************
Yes, that would be a "cross linked poly" Not best but OK!

************************************************** **

That makes a lot of sense and clears up that for me. If a certain resin is in the toners already, that may not be possible if I understand correctly. The toners on that UTech system for instance are a "Virgin" toner with no particular direction in technology. You add the resins to make it a lacquer, enamel or Polyurethane, right?
*************************************************8
Yes, a great idea! But now that ****kins bought them, its probably messed up by now! I meant Sikkens sorry for the error!
************************************************


Is this like the S-W "Dimension" line? On the same bank you make synthetic enamel, base coat, acrylic enamel, and SS urethane. I found it to be a pretty good system. They have some problems with slow cure times but over all I thought it was pretty user friendly.

But back to the mixing ratios, they really don't mean a whole lot when it comes to determining if they are poly or just urethane because of the different amounts of iso's that "could" be in the hardener right?
************************************************** **
Thats right, want to make a real profit? Take a urethane and make it a 3:1 mix. Now you have 3 gallons of clear instead of 4 and the hardener is diluted with very profitable solvents.
This would pay a lot of bonus to you rich sales people!

MARTINSR 07-24-2004 03:29 PM

Barry, I never was paid bonus off of GP, it was increase in sales, period.

The only time GP on a partiular product was ever mentioned was that we were told to only "give away" core products. If something was to be comped it was to be a solvent or clear. Other than that, it had nothing to do with our job.

I thank you very much for the explainations, it really clears a lot up. Brian

loiselle 08-31-2005 10:05 PM

Help, I am confused?
 
I am building a street rod. I have happily used Rustoleum Stops Rust Automobile Primer (2081). Now I am getting ready to paint. Nobody knows what kind of topcoat is compatible with this primer. Rustoleum says that it should be compatible with most auto paint except maybe lacquer. Do I need to put a primer/sealer on top of it? If yes, what do I use? Is this primer compatible with urethane, polyurethane, epoxy, and acrylic enamel paints?

What is the real difference between enamel, urethane, and polyurethane? I see the word acrylic used also. Some are oil based, some are water based, and some are solvent based. This is really confusing. What are the pro's and con's of each one of them.

I am not looking for a show car, just a nice looking driver so I can attend rallys and rod runs. It has been suggested that I use an acrylic enamel and then top coat it with a clear urethane.

Some one help this old man. It used to be simple, enamel or lacquer depending on how much work you want to do.

Larry
ditvenet@hotmail.com

n66ht 09-01-2005 01:36 AM

So you can add resins with the "mixing clear" to the toners in the formula and make a true polyurethane because you are simply adding different resin making it "poly"?
************************************************** ********
I remember using SW U7000 system and when we had to touch up a chip etc. I would mix up the color in a small cup with the single stage mixing clear(binder) in stead of b/c mixing clear. Add urethane reducer in stead of b/c stabilizer, a drop of smoothie a drop of urethane hardener and touched up. The paint would come out glossy not flat looking like b/c and it would harden up and stick like s/s.

Gordo84 06-20-2011 03:55 PM

Can anyone give some info on this cross linked polyurehthane? thanks

JohnnyK81 06-20-2011 04:52 PM

So what base coats are polyurethane? Perhaps I'm misled/confused by this whole post.

My prospray sitting here is 1:1, but it says acrylic urethane on it. Does this only apply to clears and SS's?

Gordo84 07-02-2011 06:58 PM

You gents seem to be very knowleagable in the field of paint. Not to be off topic but what kind of paint was used by general motors in the 80s.. specifically 1982-1987 c10 truck line? I thought acrylic enamel was used.. however i have been told perhaps it was lacquer.


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