Clear Coat Chemistry Lesson?

E

earlysecond

Can someone point me to resources where I can learn basic chemistry and the pros and cons of each clear product that follows:

1. Urethane Enamel Clear

2. Acrylic Urethane Clear

3. Polyurethane Clear

All are clear coats, all are urethane based I have sprayed all but the enamel (this is what summit is selling to top coat their SS paints and it is creating some confusion in amatuer/hobbyist settings)

I know that when I mix and spray a 4:1 acrylic (Pro-Form, Omni) I get a watery thin but easy to spray clear that builds very little film per coat

I know that when I mix and spray 1:1, UV clear I get double the film build and a deeper appearing gloss

I am just looking to understand the basic and am willing to look it up myself. BUT if someone can give me a down and dirty quick answer. . .all the better.

Thanks in Advance,
Brent
 
None are the same and there are no urethane police.

Some companies are really bad at taking cheap enamel and because it passed buy some urethane, call it urethane. Polyurethane is not much better, some say buy using this activator, it is now a polyurethane??? How beats the crap out of me.

When you get to the cheap or low grade clears, anything goes as it is price only and you have a lot of people with their hands in it, making a profit before it gets to you, so cheap is the word.

Withe the major brands, PPG, BASF, DUPONT (not their cheap lines) you can be assured of getting an acrylic urethane of decent quality and each have one clear that is top of the line for high end or show cars, such as PPG 2002 a great polyurethane and Dupont had the 7800 another great Polyurethane for their restorations.

So to answer you question, the name means nothing because there are 100's of different polyols (core resin of the clear) to chose from and the polyol is the most important ingredient.
 
Barry,

Thanks! I wish I could do even one day preceptorship/mentor session with you. This stuff facinates me. I like it so much I talk about it too much. I encourage most everybody to at least check out SPI. Too many of them are buying crap from Summit, mixing and matching and are disappointed with the results. I learned what little I know the hard way. I learned what does not work when I had to scarpe/sand off my mistakes and start over.

In discusions on at least one forum. . .I seem to really peeve off the "professional" painters when I talk about SPI, the differences in clear coats in differnt brands. I get the hobbyists pissed when I ask them why they would buy Summit enamel SS try to spray it with a $50 gun then have to put clear on it anyway?

I guess that I am just the guy that needs to know how it all works. .. the Good Lord made me that way, it is irritating to many!! Sorry blame God! haha

SOOO, If I hear you right, there is no true standard for what can be called "urethane" because there is no governing authority?

People are then buying enamel paint from race shop warehouses and thinking that they are getting something else? (looks like repackaged Kirker or SW SS to me) They love it because they can buy a complete "paint system" (primer to top coat) for $300 and THAT seems to be all that matters. . .until they try to spray it or cut and buff it!

There IS a difference in polyol content between acrylic urethane and polyurethane? More polyol chains are better for gloss and retention/durability?

Obviously, not all clears are created equal. I want to be able to explain to my friends why SPI UV clear is superior to OMNI or Pro Form (choose a name) acrylic urethane clears.

Help me to explain this and I will continue to steer hobby painters to this site and to the order line! I only recommend SPI because I have gotten fantastic results. I want to share what I have found but I end up spending too much time debating and getting in peeing contests with guys who are married to paint reps! (I bet you know a LOT about this topic)

Above all, I want to make sure that I am not "talking out my butt" and can continue to educate, even the price buyers. My experience is based on the fact that I ignored this site for years, despite many recommendations. I bought all of my supplies locally and was pretty cheap. I did not do enough research. I allowed the counter guy at my jobber to sell me acrylic lacquer primer to use as high build between epoxy and SW base coat. . .you can guess how that worked out! I want to educate other hobbyist so that they do not make the same mistakes.

Thanks in Advance as Always for sharing your expertise

Brent
 
In all fairness most people just don't understand and you would think a place like Summit would be more concerned with reputation, then making a few bucks, looks like they are doing pretty good with the stuff but I would say no professional painter would ever buy it and when you read stuff like S&W base is the same as PPG base or I sprayed my car 10 years ago with restroleum and it still looks like new, just kind of goes to show,t here are a lot of cut and pastors around and a lot of onetime expert knowledge to go around.

I want to see what the cheap Viper red looks like in just a year of driving, wait, I don't need to see it, I know what it will do, same with the restroleum, I know, so its hard for me to keep my cool sometimes.

You can explain this stuff until your blue in the face and it still does not make a difference to some people.

People do see a difference, we in a short time have taken over from PPG a small to medium size town in NY and they sent the PPG rep in to get the business back, this week.

Flexibility and chemical resistance are just two of the things that will make a polyurethane stand out.
He said to a number of shops, we will match any price to get these guys out of here, and best of all was the one bigger shop told the guy, you have nothing as good but maybe I would buy the 330 wax and grease remover from you, if you can beat the price.
 
Buying paint from a race warehouse is like calling you and asking you to sell me a set of headers for a Small Block Chev and telling you that price is all that I care about.

I guess that preaching does not help the professionals you serve so the hobbyists are even more confused.

One of the main reasons I have aske people to check out SPI is your knowlege and willingness to provide round the clock tech support to pros and hobbyists alike.

Glad to hear that you took and will retain business from the majors. No small feat, but well deserved.

Someday, once again, perhaps the American consumer will once again focus on value. Until then nearly everything is cut throat and price based. Not to get to political, but what would happen if consumers could no longer buy stuff that was imported for pennies on the dollar of what something a bit better would cost? It is interesting to me that anybody would spend a month block sanding a loved project car to perfection and then roll on some Rustoleum enamel or spray the equivalent! Not sure that I get that mentality NOW but I did that when I painted my car (cheap products, wrong products in combination to save a buck). Either I am a hypocrite or I care to share too MUCH!

Have a good One,
Brent
 
earlysecond;1186 said:
I know that when I mix and spray a 4:1 acrylic (Pro-Form, Omni) I get a watery thin but easy to spray clear that builds very little film per coat

I know that when I mix and spray 1:1, UV clear I get double the film build and a deeper appearing gloss

Brent
Click to expand...

I think the UV clear is also the thinnest viscosity clear SPI has...
 
old thread here i know, but a thread on another forum got me thinking.

so whats the major difference to a polyurethane clear and an acrylic urethane clear? Nothing really? If it is a high-grade urethane from the top companies, is there a difference other than words on a tech sheet and marketing?
 
Yes, I guess that is my biggest question the difference between acrylic urethane and polyurethane. Obviously poly means many and sometimes more is better.
 
jeremyb;5555 said:
old thread here i know, but a thread on another forum got me thinking.

so whats the major difference to a polyurethane clear and an acrylic urethane clear? Nothing really? If it is a high-grade urethane from the top companies, is there a difference other than words on a tech sheet and marketing?
Click to expand...
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9 times out of ten, your non really applies in this business.

Real poly's do stand out, as they are difference, that is why the BS stops at the commercial aviation door, as no urethane could ever pass the skydol test or the 30 below to 300 degree test (for long)
 
One way to think about this is that the term urethane refers to the linkage that holds the major pieces of the coating together - much like bolts hold a car together. Urethane linkages come from polyol reacting with isocyanate. since there are only a handful of basic isocyanate building blocks that are uv stable, and because the part of the coatring that comes from the isocyanate makes up a relatively small (but important) fraction of the coating, the polyols that are used make up the bulk of the coating and result in the biggest differences in properties. There are a lot of polyols available and no doubt some major magic in getting just the right combination of them to highlight a particular performance characteristic (including cost...). I'm fairly new to the details of automotive coating technology, but have been doing isocyanate chemistry and coatings chemistry for years... I enjoy learning more on sites like this... oh, and the universal clear looks fantastic on my truck over dbc base coat - I'll need another gallon as well as more epoxyt, etc.. soon. :)
 
Please understand my curiosity is not designed to pry or have trade secrets divulged. . .mostly it is so that I know what I am talking about when debating "pros" (wink, wink) on other sites who have used ONLY product XYZ from manufacturer ABC for 10 years and everything else is bathtub junk. The other end of the spectrum are the I'm gonna spend as little as possible on paint as I can but expect to pull of a great job. They buy Summit SS and decide to put clear over it for UV protection. Really fighting an uphill on this one!

I like to be informed. At a chemistry level I am trying to learn. Although I loved the many practical lab classes I have taken over the years. . .there can be no successful lab without the accompanying lecture!

Thanks for taking the time to explain,
Brent
 
earlysecond;6637 said:
The other end of the spectrum are the I'm gonna spend as little as possible on paint as I can but expect to pull of a great job. They buy Summit SS and decide to put clear over it for UV protection. Really fighting an uphill on this one!
Click to expand...

That is a great point!! Its an uphill battle that will never be won because someone has done it and pulled it off, so it must be the way to paint automobiles for next to nothing.. Im done arguing that point on the internet.. I had my last conversation regarding that shit not too long ago..
 
earlysecond;6637 said:
Please understand my curiosity is not designed to pry or have trade secrets divulged. . .mostly it is so that I know what I am talking about when debating "pros" (wink, wink) on other sites who have used ONLY product XYZ from manufacturer ABC for 10 years and everything else is bathtub junk. The other end of the spectrum are the I'm gonna spend as little as possible on paint as I can but expect to pull of a great job. They buy Summit SS and decide to put clear over it for UV protection. Really fighting an uphill on this one!

I like to be informed. At a chemistry level I am trying to learn. Although I loved the many practical lab classes I have taken over the years. . .there can be no successful lab without the accompanying lecture!


Thanks for taking the time to explain,
Brent
Click to expand...

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Brent I understand what you are trying to accomplish, how ever here are the SAD facts!
"Buyer Beware"

No matter how much you know, you will not know what you are buying in this industry, yes if you buy a majors premium brand, it is going to be of good quality and most likely last a long time, buy their cheap brand and buyer beware, I have seen red base turn into red oxide in less then a year in the south, I have also seen it look good for 2-3 years.

Off the wall companies, you just don't know, they can't pay their supply bill and next thing you know there is a bunch of clear out their with very little UV protection as UV is the most expensive thing in a clear.

Ten years ago a dealer in GA had all 43 jobs done on new and used cars with a clear and they all started to fade in a week (depending on color) P- Rico had over 400 cars go bad.

No company is going to state what and how much UV's are in their clear or what resin grade they are using or if they ran out of a clear ISO and used a Primer ISO instead because they could not keep their bills paid.

I had a call from one relabeler a year ago wanted a 10,000 gallon batch of 4:1 clear made. I said what kind of quality, UV protection do you want? Just want a good price!
They had no clue what they were buying and this is a big company, if I would have bidded and came in 50 cents a gallon less, that business would have been mine, sorry I sleep good at night and don't need or want their business.

Sometimes the more you know the more you know the more frustrating it is.

Buyer beware!
 
Thanks Barry,

I have an idea. . .given the information that you shared. As long as your products are consistently the best value and continue to outperform products I have used that cost a lot more, I will just buy stuff from your company. Additionally, based on my experience with SPI, I will continue to promote SPI products on other boards I frequent. I understand what you are saying. Bottom line is results vs. dollars (not just one or the other) is the oversimplified equation. I will leave it at that and thank you again for what you, and others here, have taught me. NOW if I can find time to do sheetmetal and bodywork, I could actually mix a batch of clear. I cannot wait!

Brent
 
There is no way for the buyer to beware, when there is no way to know what is in the product.

i have based my buying decisions almost purely on trust, since the testing I'm able to do at the shop is not comprehensive.

It seems so strange to me that there is no standards body to test and certify topcoats. A bad paint job can take as much value away from a vehicle as a bad engine, yet there multiple standards organizations in place to test engine oil, and none for coatings that I know of.
 
It seems so strange to me that there is no standards body to test and certify topcoats. A bad paint job can take as much value away from a vehicle as a bad engine, yet there multiple standards organizations in place to test engine oil, and none for coatings that I know of.
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Same with roof shingles, treated wood, house paint deck paint, oil filters, furniture, clothes==the list goes on and on.
 
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