Urethane paint, need the basics.

[Chas SCR]

Gary what clear did you use? And what ratio is that? Clear to activ, is 4 parts clear to 1 part act, I know PPG has a self leveling clear in there line like Du Pont has the Hot Hues and Nason line. I would be carful on using the dehydrator for drying the clear coat.. This could make it very hard for you to do any wet sand and buffing to get stuff out.

[roadhawg]

That does sound like a weird ratio. Like Chas says, the standard for most brands is 4:1:1. The dehydrator isn't going to do much...catalyzed finishes "cure" by chemical reaction, not "air" or heat.

[slapshot]

As oppose to 4 to 1 to 1, I went with two to 1 to three. I used one quarter increments & reduced it a little more. I do like to experiment & with mixing these small amounts I only wasted about one ounce. My main concern was that it would be to thick. Turned out it was a little to thin. I will make the adjustment next time. Every model is a pratice for the next one. I kinda went with Tom Miller's formula. He has a 1950 Austin Gasser posted under the New Kit Review sub forum. He clear coated it with Urethane clear & boy does it look awesome. As promised here is a pic of the hood. I do not know how one could get this any shiner. But if there is a way I will try it.

Edited August 24, 2010 by slapshot

[Karmodeler2]

Gary what clear did you use? And what ratio is that? Clear to activ, is 4 parts clear to 1 part act, I know PPG has a self leveling clear in there line like Du Pont has the Hot Hues and Nason line. I would be carful on using the dehydrator for drying the clear coat.. This could make it very hard for you to do any wet sand and buffing to get stuff out.

Hey Chas,

I'm not sure who has told you that you have to wet sand right away but they have mis-informed you. Chemicals such as paint are made up of many different chemicals and these chemicals, when mixed together, have reactions and results, which is what we are after. However, they tend to gas out much longer than the 72 or 16 hours that the spray out sheets talk about. In fact, it can take up to a year for some paints to cure, while they may dry in the hours specified for the product. I have painted a model, and one week later cut & buffed it, only to pull it out of the cabinet a year later for a model show, and it's full of orange peel. It was not that way when I put it away.

That being said, I now wait at LEAST one month (mark it on the calendar) and sometimes longer to cut and buff. I have never had a problem with wet sanding or getting a finish that is nice. If it's Tamiya clear, I start with 3000 or 4000. If it's PPG urethane, I can cut it with 2000 first, then work up to 12000. I just did the Cunningham below and it was shot with Tamiya clear, waited a month, cut it with 3000 (sanded it) and then used their blue cap polish, their white cap polish then the green liquid wax. I did not go past 3000 with sand paper. As you can see, the sun is reflected in the pic, along with the camera lens below the trunk line. Not a bad finish and I know it's gassed out most of the solvents that it is going to.

I know that high end paint shops (restoration facilities for the Duesenbergs, Bugatti's and the like) will paint a car and wait for a year to cut and buff. So it can be done with awesome results. And a year in full scale is 15 days, so I'm a little past that (yes, this is sarcasm).

In this last pic, you can see my head, and camera taking the shot. This car was cut and buffed 2 months after I shot it (cause that's when I could get to it. It has been done for 2 years now.

Hope this helps.

David

[Chas SCR]

mis-informed? Dave I work very close'ly with the Du Pont people here and also learn a lot of stuff from one of the top air brush people here on the west side of Michigan. For getting orange peel from clear coat? Is that from using PPG, that would explain it all right there.

And for buffing out right away no.. I do not even look at the body for the first 4 hrs till its some what dry. And 99% of the time there is no wet sanding or buffing or even polishing if you do it right..

[Karmodeler2]

mis-informed? Dave I work very close'ly with the Du Pont people here and also learn a lot of stuff from one of the top air brush people here on the west side of Michigan. For getting orange peel from clear coat? Is that from using PPG, that would explain it all right there.

And for buffing out right away no.. I do not even look at the body for the first 4 hrs till its some what dry. And 99% of the time there is no wet sanding or buffing or even polishing if you do it right..

4 hours?.....I'm talking 4 weeks.

And the orange peel is something that surfaced AFTER I had cut and buffed (too soon mind you) and placed the model on a shelf, only to pick it up a year later and see the entire body had finally gassed out and created an orange peel effect on a surface that was final cut with 12000 grit and then polished to a mirror finish. All I was trying to say is that letting something gas out for a month or more will not prevent you from being able to cut and buff it. You implied that it would be, and I felt you were mis-informed on that particular fact.

....and 99% of the time? Are you saying that only 1% need to be cut and buffed? There is no painter in the world, who can paint a concours paint job that needs no cutting or buffing even 30% of the time. I have been to several restoration shops, and have restored two cars myself, and have been to Leno's Garage, The Nethercutt collection (winners of BOS at Pebble Beach more than the next 3 competitors combined) and other high end shops and even THEY can't paint cars that don't need attention when they leave the booth. If you got someone who shoots paint that needs no cutting or buffing, then I'd like to see the guy who could put all the companies that make sandpaper, polishes, buffing pads, and buffers out of business!!! Please share the pics of your work, or his to show us what you mean.

Sincerely,

David

And this one was left alone for over a month and I spent around 8 hours on the hood cutting and buffing, so you can imagine the rest of the vehicle. And it was in contention for Best Paint at GSL , but my Aston Martin beat it.

[Chas SCR]

You way mis my point..You just stating that your way is the right way and thats not true.. A model is a heck of a lot different then doing real cars for one. Two The person that does the real stuff has had stuff win great awards for his paint jobs at Detroit Auto Rama and at the Goodguys show's down in Indy and also Ohio.

I do have some of my work you can see. You have seen it at the GSL, The truck looks good but no different from any one els that was on the table that look like a trailer queen style paint job.. It's the paint under the clear that makes it look better not the clear, and plus you won your class so it would go after the Master awards (Paint) being one of them.

Dave are you talking about Waxing or Buffing it out to wait 4 months? Du Pont recommends to wait no less then 1 month before putting on a coat of wax.

Edited August 23, 2010 by Chas SCR

[Karmodeler2]

Chas,

Let me address your response as I go, since you have stated some obvious things to me, that might not be so obvious to you.

"You way mis my point..You just stating that your way is the right way and thats not true.."

Not true. I never said my way was the "right" way. Read my post. I said you were mis-informed. I was saying that your statement of having to buff the car with in hours or days was incorrect.

"The truck looks good but no different from any one els that was on the table that look like a trailer queen style paint job."

The truck won it's class, you are correct and was in contention for best paint, so it must have been somewhat different than the others on the table. If it was not different, it would not have won, it would have blended in with all the others. Also a fact for you is that you do not have to win or place in a class at GSL for the master awards. My Aston Martin did not even place, but went home with best paint. So your statement about my truck is false when you said "you won your class so it would go after the Master awards (Paint) being one of them"

"A model is a heck of a lot different then doing real cars for one."

Not true, If you are using automotive base, reducer and hardner, then the only difference is size. You spray side mirrors on real cars and they are not much bigger than 1/18 scale cars or sometimes, even 1/24, depending on the 1:1. But the rules of the chemicals do not change. They don't know what they are going on, so the properties do not change.

"It's the paint under the clear that makes it look better not the clear"

I have to say that this could not be true. If you laid down the sweetest base, and put a crappy clear coat over it, you would still have an ugly paint job. The base did nothing for it. The two work together, and when done properly, compliment each other.

As far as waxing or buffing, they are two different things. Waxing is something you do long after the paint has dried and cured (read the spay out sheet). Buffing is something that is done after sanding and prior to putting the car back together (on a ground up). I do NEITHER for at least one month and sometimes longer.

There are several ways to do things and get similar results. This is my TECHNIQUE. It has garnered several Best Paint awards for me over the years (not bragging, just stating the facts) and when countless people ask you for your technique, and you do seminars at places like GSL and the IPMS Nationals on paint, then someone must think you know what you are doing.

Hopefully this will clear things up for you.

Sincerely,

David

[Scale-Master]

It is my opinion that if you want to learn how to work with urethane's and have the least amount of headaches you should follow David's advice. The points he makes mirror the same experiences I have had, and I have seen his paint/finish work in person. "Dave's way" is one of the many right ways to paint. Just look at his results.

Chas's comment amounts to bad mouthing a DuPont competitor's product, instead of accepting someone else has the ability to paint and is willing to properly teach others. Brand loyalty is one thing, ignorant snobbery is another. I know a lot of people who get great results with both PPG and DuPont products. I also use Matrix and PCL clears and DuPont Chroma colors. Snidely portraying a product that looks to be applied with better results (than the product you are using) by someone else is bad form and serves no purpose.

Not finishing the paint after it is sprayed is often the difference between being complacent and accepting what was shot, (which is fine if you are happy) and really making a 100 Point finish. Remember, you have to build for yourself...

Real car paints look like real car paints when properly applied to models, the only problem is they often look out of scale due to the way they lay down. Cutting and finishing them properly can bring them into scale. Some soft flowing cars can get away with comparatively thick but smooth uncut finishes. But what treatment do the best of the best real cars get after being painted?

David's photos really don't do the paint quality justice. That green truck won best paint because it is flawless, I know, I was there. Seriously, no defects. Take a second to think about NO DEFECTS. Honestly, how many absolutely perfect paint jobs has anyone seen? It may look boring, but that just leaves less areas to hide any imperfections. And speaking of those photos, thanks for wearing pants in that last one David!

Also follow Ed's advice about the respirators to avoid headaches.

You can also add me to the list of lacquer thinner users...

[Karmodeler2]

. And speaking of those photos, thanks for wearing pants in that last one David!

You are welcome....it's the least I could do. (Sorry about the past photos....I'll pay for your therapy!!). If you look close, you can see you house!!!

David

[Jeff Sauber]

Um, judging by the images shown, it's pretty darn obvious that David knows what he's doing.

There's lots of ways to try and achieve decent finishes, but David's advice is solid and clearly very effective.

I can't see how anyone can argue the point...

[Len Woodruff]

I use Matrix too. It seems to be just perfect for models since it is thinner in the 4:1:1 ratio.

Which Matrix do you use Mark?

[Chas SCR]

Dave, Mark I was not trying to bad mouth PPG.. Do I care about what there recommendation's are "NO". I ask for what Ratio did he come up with for what product and Dave and My self has been the only one to say what we us... For how I do it and what I put up here is the minimum working with there product.. Once you shoot the clear you have a 0 to 4hr window to put another coat, If you miss the 4hr window you must wait 72 hrs to do another coat.. You can start your wet sanding and buffing min of 2hrs after shooting it. If you wait with Du Pont (Dave's way) You would have a lot of extra work ahead of you... This was also stated from another person that has done good at the GSL Tom Nungester who is a body paint person for a living. Now Dave congrats to you on all your awards over the years.. But at the same time I do not think a lot of people here has 4 months to wait.

[Karmodeler2]

Now Dave congrats to you on all your awards over the years.. But at the same time I do not think a lot of people here has 4 months to wait.

In my 35+ years of building models, I have never seen a model with an expiration date on the box. Any time constraint is strictly imposed by the builder. We all have 4 months to wait. It is whether we choose to do so or not. (and to help you out, it's 4 weeks........not 4 hours, not 4 months......4 weeks that I wait for my paint to gas out...which is my technique).

Most eye catching models were not built over night.(Except for Mark Jones ) It takes time to do it right, which is where most people make the choice to just get it finished vs. doing it correctly.

Just my 2 cents.

David

[Guest madazzskilzkustumz]

Chaz biuldz nise stuf evren if he piants it hiz own whay. I lik hiz stile and am going to coppy it . I like plasticote paint an tesers paint bests. thanks! Jimmy

[Scale-Master]

I find it interesting the one person is offering firsthand experience and sharing his method and results, and another is trying to justify his methods as being the better way by bolstering his claims of experience with second hand knowledge he got from friends and acquaintances.

Just a footnote, I have been employed as a “real†automotive painter as well as a model painter. Doing is way more conducive to learning than talking and telling what was heard from someone else.

And it is Mark Taylor the one that can build the 24 hour wonders, not me.

As for the Matrix, I use MSV-21. California has restrictions on what we can purchase…

[Danno]

You are welcome....it's the least I could do. (Sorry about the past photos....I'll pay for your therapy!!). If you look close, you can see you house!!!

David

Add me to the list that thanks Dave for wearing pants when he photos his builds!

And, not only can I see Mark's house ... but I can't get its image out of my head ever since Steve Keck posted that pic.

I'm trying spraying with 1psi. I set it up yesterday. I'm still waiting for the paint to arrive; I think the air is about 1/2 way through the water trap now. I'll keep you posted on my progress.

Maybe I've whiffed too much urethane.

Good discussion, people. Carry on.

[Jeff Sauber]

In my 35+ years of building models, I have never seen a model with an expiration date on the box. Any time constraint is strictly imposed by the builder. We all have 4 months to wait. It is whether we choose to do so or not. (and to help you out, it's 4 weeks........not 4 hours, not 4 months......4 weeks that I wait for my paint to gas out...which is my technique).

Most eye catching models were not built over night.(Except for Mark Jones ) It takes time to do it right, which is where most people make the choice to just get it finished vs. doing it correctly.

Just my 2 cents.

David

I agree.....I tend to wait 4-6 weeks myself just on the paint curing process... I have tried to polish out finishes before they were COMPLETELY gassed out and cured, only to find a bit of "texture" return a few days after the polishing sessions were completed....[which of course meant that the paint was still curing]....

I try and never rush my projects. If I have the urge to keep working while I'm waiting for paint to cure, then I'll get started on another project in the meantime. I usually work on 4 or 5 different cars at once, so there's always something to do as the final body paints are curing up.

Heck, if I'm lucky, I'll only get 2 completed projects done before year's end.

I'll leave the 24, 48, 72, or whatever "hour builds" to the speedy folks....I have no desire to build models in a hurry. I'm not saying that's a bad way to build stuff, but it's certainly not my preferred approach to things.

Thanks for sharing the great Paint tips, David....Most of us here deeply appreciate it.

Edited August 24, 2010 by J. Sauber

[Karmodeler2]

You are welcome J. It's the least I can do to pass on what has been taught to me.

David

[Steve Keck]

So, it's do as you say not as you do?

[Steve Keck]

For those that think I'm being harsh with Steve, first I'm kidding...least about the daft part, and second...he has it coming. Honestly.)

Honestly? Don't you have it backwards?

[bigmikevee]

Hey Gang,

Been reading this with a lot of interest, have heard so many pro's & cons about the urethane, and still not sure if it is right for a amateur like myself. Still using Testor products in trial-and-error spraying (you should see my spoon collection, what I practice on, it is really getting awesome!!) and liking, to a point, most results. Because of where I live, have been drying things out in the sun for a couple of hours, no smell and hard as a rock when I bring them in, was going to get dehydrator for the cooler months, but now I am reading this doesn't always help paint cure? If the chemical process has to take place, will the heat from the sun just waste time or the dehydrator be a waste too? Still have many, many questions about paints and painting, but this made me stop in my tracks, now feel really confused. Can I get a little more info on what exactly happens here, thought "gassing out" meant the thinners and drying agents have to completely leave the paint, then it is "cured", thought heat helped, but what is really happening?

On a positive note, David, green truck is stunning, don't know about not wearing pants when taking pictures and don't wanna know, and the rest who commented and posted pictures, thanks so much, ALL the pictures are so enjoyable, this forum just makes my day. Thanks in advance for clearing up my confusion, if I ever get a really good paint job, I will post, pants included.

Mike

[Karmodeler2]

Hey Gang,

Been reading this with a lot of interest, have heard so many pro's & cons about the urethane, and still not sure if it is right for a amateur like myself.

Mike

Keep in mind Mike, that I was an amateur (and still am, kind of) (yes, I know...preposition!!!!) until I started using this stuff on a regular basis. There are hazardous, but if you buy a real good, changeable charcoal filter, type mask, and WEAR it when you spray the stuff, you will be okay. I, and a lot others, will just shoot a few small parts without wearing the mask, which is wrong.

The paints themselves are very easy to mix and spray and the tips that are on the info sheets will help you. I was intimidated at first, just like with casting my own parts, machining and the like, but after working with the stuff, I think I'm over that now.

I would encourage you to try it. That's how I ended up using it....I just tried it and liked it. I tend to add a little more reducer than recommended so I can get it to lay down nicer and flow better.

Remember, the model paints use oxygen to dry. (enamels along with typical lacquers) When you get into the urethanes, you are expediting the hardening/curing process by adding a hardner, and either speeding up or slowing down the drying/flowing time with the reducer. It's just that simple.

And the green Chevy Pickup is Tamiya British Racing Green, with Tamiya clear on top. So if you have this stuff, you are half way there. I use Tamiya and automotive urethanes, and just about everything in between.

And the best way to improve is practice. So get some plastic spoons, put a simple base color down (silver, black, red...just a color nothing fancy like candies) and then mix up some urethanes and use different PSIs and mixes to get the result you are looking for. It's a cheap way to practice and you can get free spoons at McDonald's. Spray the back side and write what you did to get that look on the inside of the spoon.

Hope this helps.

David

[Karmodeler2]

Hey Mike,

ask Bob Downie about the dehydrator and if the paint ever settles more after out of the dehydrator. Since I am using mother nature, the time it takes to cure is much different than the time it takes to dry. (I think Bob can cut and buff in about 8 hours and he uses all kinds of paint. His name on this forum is Zoom Zoom).

You are correct that "gassing out" is where the chemicals release their solvents and the like and settle down to their final state. If you could imagine a rough surface, not as drastic as a gravel road, but something like this in scale. You spray the urethane down and it looks really sweet. The clear coat fills in the rough edges and "smooths" everything out. Well, if after 16 hours or so, you cut and buff it, you can polish it to a shine. However, that surface under the polished one, is still there, and as more solvents leave the clear coat (gas out), the clear coat fills that void by shrinking down a little. In a few days, you have a rough finish that was not there when you polished it out.

It is my understanding that the dehydrator accelerates this process and removes all the solvents and expedites the dry and cure time by using dry heat to do it. In the south, humidity is our enemy. I use CO2 instead of compressed air to get around some of this. I have yet to use a dehydrator, but I do use my oven, and will get it up to about 100-120 (lowest setting) and put my car body in for just a few minutes, rotate it around (on the hanger it's on) and then remove it. I do this several times to flash cure it. Similar to the oven bake type jobs, but I can't leave the model in there because it would melt. I still wait for a month, even after doing this.

I am sorry that I confused you with so much information, but I wanted to give you as much as possible to motivate you to try it. Some of what I have shared I had to learned myself and it would have been nice to have some of this up front, so that is why I shared so much.

David

[Steve Keck]

buy a real good, changeable charcoal filter, type mask, and WEAR it when you spray the stuff, you will be okay.

David is correct in all he wrote, however, I would add to wear the respirator even while mixing and clean-up. And, run the fan all the time as well.

Steve