Lets talk paint........base/clear....etc.

[Tman]

All I can say is WOW! I sprayed my first base clear today. I spent most of my teens (80s) painting and working with a family friend in his one man body shop but never got the chance to do this stuff. We did lots of Imron etc. Today we sprayed my steel wheels, see this post.

http://www.jalopyjournal.com/ubbthreads/showflat.php?Cat=&Board=UBB1&Number=201527&page=0& view=collapsed&sb=5&o=14&fpart=1


The base went on like frosting without any bobbles!!!! Even the primer was like butter. I dont remember paint working this well? I could lay down some nice paint before but this stuff was cool, made me feel like a pro.

Makes me wonder what to expect from my single stage Urethane that I planned on using for the Touring? Does modern single stage spray as well as the base/clear?

I have a bud that is a PPQ rep so I shot Omni, I like it, even the price! That high build primer was pretty killer as well (pink stuff I forget the #)

Just am excited about finally getting to do some painting again. I did not realize it but I have spent a decade jonesin to do this.

Any of yoose that do much of this have thoughts? Ideas? Tips?

[lowsquire]

Ive sprayed about ten cars in the last year or two, and have only ever used acrylic laquer top coats,as i dont have a clean enough space to do urethanes,but Im sure ive got the skills now to try it,so im also lookin forward to trying this 2pack stuff out.its got to be easier than acrylic!
I do use 2pack hi fill primer, and its the best.holds out great and makes for a smooth top coat.

[hatch]

Urethanes require heat and airflow to properly cure. With out it, you can have delamination later on.

I prefer single stage over base clear..easier to spot repair if you are using solid colors....dupont chromapremier is my favorite....killer stuff with a fairly long window for wetsanding and polishing.

[MercMan1951]

I worked in a body shop while going to college for 6 years (no, I'm not a doctor now-so shush).

After painting countless cars, and speading more body filler than I care to imagine, I can say I'll take base/clear, hands down. You can shoot it in your garage with minimal cleaning (blow it out & wet the floor), and if you hose on 4-5 coats of clear, you can get out the dirt when you wet sand. You don't have to worry about moving the flakes around on metallics when you rub, either. I'm sure you know what I am talking about- ever rub a single stage heavy metallic car? http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif

I hated urethanes, there is little forgiveness, and Lacquer was for trim only... BC/CC is the way to go.

All of the reducers/hardners are a pain, and expensive. That is the drawback.

But you say you've used Omni, that is a really good paint. And yes, their primer isn't bad either. About 3/4 the price of the "real" PPG stuff. I think it's just leftover PPG paints anyways, it sure smells the same in the air. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[manyolcars]

I've seen a lot of finishes with the clear coat peeling off. It makes me wonder if base coat/clear coat is not such a good idea.

[MercMan1951]

Manyolcars- It's all about the prep work... you can't cut corners with the modern paints.

This brings to mind some more info I have running around my brain-

When you see those 5-10 year old cars running around with factory paint that has the clear peeling, it's most likely the fault of poor maintenance. You still should wax them regularly. Add to that, the factory paint on many cars is VERY thin...I guarantee a BC/CC paint job done by a local shop sprays WAY more clear on a car than the factory does.

You only have so much time between when you lay down your last coat of base, and your first coat of clear depending on the brand. Too much dry time, and the clear won't bond right. This may be why you hesitate with clears "peeling off". There were some stories I had heard, that sometimes on the assembly line, some unforseen circumstance shut the line down prematurely, and the cars sat longer than they were supposed to before being shot in clear. Then when the line started back up, the base really should have been scuffed up first, but wasn't. That's another reason you see cars running around with the clear peeling off, usually on the hood, roof, and decklid. I have seen a lot of Chrysler Neons running around with gigantic circular patches of primer showing through where the paint& clear has completely fallen off...I suspect a scenario like I have described happened to a bunch of these cars...

Ford had a problem with a run of trucks in either midnight blue or silver back in the '80's...it was called D-LAM (de-lamination)...the clear wasn't sticking to the base because of a production error...Ford had to repaint thousands of those trucks... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Roothawg]

I agree with mercman...a lot of guys are under the impression that they can wait a day between base and clear...if you do..it will peel.

You can extend the potlife on the car by spraying a coat of intercoat clear to keep it hot. For instance if you are spraying a lot of graphics and it takes a long time to do your lay out...that's where the intercoat clear comes in.

I have some Harleys I painted 10 years ago with bc/cc still running around. The only problem I seem to have is solvent pop....I have had some parts that no matter how clean or how much prep work ...sealer etc. It just draws the solvents out of the primers/sealers. Those aren't a every time deal so it could be something I touched with no gloves etc.

[Fatchuk]

This is a very interesting post.....I hope there is more discussion on this subject..I have painted a fair number of cars over the years and can remeber the cheap old enamels prior to hardners and additives...except for lots of fish eye eliminater..There has bee a lot of changes in paint over the years and I'm sure in all the materials that are used under them to prepare for the paint..and lots of advacement in spayguns....it wasn't all that long ago that that was no such thing as the cheap guns you can buy to-day and they are pretty dammed amazing at how good a job that can be done if you just take a little time and study the theory of whats supposed to happen when the paint hits the metal in a varity conditions so you know whats happening when it ain't doing what it's supposed to be doing On base/clear I have always never been satified with how hard it is to keep clean It is very hard to get a nice clean job. I'm always trying to get the next one better, trying everything, but I still have a dust problem that bugs me. It's o.k. for regular customers, but I hate painting my own car in Base/clear I hate dust in my paint..As for laying on 5 or 6 coats ... I was told by the reps in my area that they would not warranty the product against peeling if we put more than 3 coats on, because they say more than, I believe 6 mil promotes the peeling process because of all the trapped solvents trying to evaporate.. I am not a very good polisher and I don't like to polish a clear paint for about to 2 weeks again to alow the solvents enough time to evaporate...and the clear to cure, no factual evidence to support why I prefer this I just do..I like to sray acrylic e-namel best and I also prefer to spray with a siphon style jGA or clone..but for most jobs I use Polyurathane it is a good forgivable paint that can be repaired esily has a nice shine, waxes up real nice, and for most people it does a pretty good job for the money...I would like to do some more Base/clear..but it is extra work you have to paint it many more times to apply the base and then the clear....and wait for that one damn fly you missed to land right in the middle of the hood...be nice to see some disscussion on this topic....fatchuk

[flyin'eye]

Roothawg mentioned solvent pop, I just had a problem with that when I shot El Ranchito.....Any pro painters out there know what causes it and how to avoid it?

[Tinbender]

Solvent pop is almost always caused by lack of flash time between coats.

[born2late]

Omni is just as good as the PPG high dollar stuff. Omni clear is less solids than most of the PPG stuff so it needs and extra coat or 2 to give the same mils. I like to base, shoot 3 coats of clear then let stand overnight. Next day come in and sand flat with 1000 paper wet and rinse well. Lay on 2-3 more coats of clear and it flows out much better than the first coats as the new clear is sliding over the super slick 1 day old clear. This allows you to control the dirt better also. It also helps with sand scratch swelling in the primer coats as you let the solvents from the 1st clearcoats evap. with that overnight cure. The less solvents you send into the primer the less the scratches will swell and the less the clear will sink into those valleys months later when all the layers dry out. Also makes for a super deep color if doing dark colors or heavy metallics. Single stage Euros will spray about the same as clear. You can do the 2 day job with them also. Most of the high-end custom shops use this 2 day technique. Helps ease the buffin also. As for solvent pop, you need to keep the heat on and the air moving all though the job and for a couple hours after your done. Bailin' on super wet coats with not enough flash time will compound the problem. Always use the correct reducer for the average temp. during the spray job. This gets the solvent out before the top skins over. Once the clear skins the solvent has to get out and will break that skin causing the crater. For dirt, wear a Tyvek shoot suit, tape the cuffs to your rubber gooves and were a cap. You will be amazed how much falls off you clothes that you think is coming from the shop air. My 2 cents from 15 years experience. Have fun!!

[MercMan1951]

Well, I can say, that I had several experiences with bugs being "curious" to what I was spraying...luckily, they always landed after the first shoot of clear. I carry a pair of tweezers in my pocket when I shoot just in case, and was able to pull out the offender before shooting more clear. I'd bury the marks left by the sombitch, just to be sure.

As for the 5-6 coats..I would NEVER spray that many. 3 Was usually the norm, 3-5 if the guy was an asshole about paint & dirt. You'll wind up sanding half of that off.

At the shop (and since-at home) I would buzz down a final coat of clear after it cured (3-4 coats, usually WITHIN 2 DAYS at 70 degrees) with 1500 Stickit on a DA to knock down the nubs & orangepeel. But you have to know what you're doing with a DA to do this, otherwise, it's wave and burn thru city- Then I wet sand by hand with 1500-2000 grit before compounding/polishing. I use 3M 5933 for a cutting compound on a number 1 Schlegel pad, followed by 5928 "Finesse it" polishing compound on either a number 2 Schlegel pad or a foam 3M "waffle" pad. I use a Makita orbital grinder/buffer, capable of at least 2500 RPM's...variable speed, even better... (NOT the Sears brand "random orbital" -they're USELESS on anything but wax removal!) After 30 days, use a good hand wax such as Meguiers or Turtle Wax (no shit!); and I've never had a problem. Faster, and way easier than (to quote my boss at the time) "sanding your balls off".

As for solvent pop, I never had much trouble with that. I remember I would get that if I either 1) Shot too much clear in one area, or 2) put the infrared heatlamps on a fresh panel too close for too long.

Maybe you guys get the solvent pop by shooting the clear too soon? Dunno. Wasn't an issue for me.

[hatch]

Solvent pop can be eliminated with airlflow and proper time between coats....see above born2lates answer. I've never heard of any other reasons...been spraying cars since 75 and I still love a lacquer job over anything else.

[Tinbender]

Here's some of what I've learned about paint and painting.

First thing, READ THE INSTRUCTIONS. Most if not all paint companies will supply you with P pages. (procedure pages) These will tell you most everything you need to know about the product your using.

Next, enviroment.
You MUST have clean DRY air. Most home air systems fall short on this one.

60 degree MINIUM temp. That goes for filler work too.

Air movement, air movement is critical. Solvents can't evaporate without air movement.

Flash times. My paint rep claims 90% of failures are due to lack of flash time between coats. Again, the solvents MUST evaporate, or they will come up later.SOLVENT POP!

A little about products. Don't mix product lines. Yeah, I know most of the time it will work out, but not always. Paint companies spend millions on R & D. They don't spend a dime to make their products compatible with other brands.
Some other random stuff:
Give up on lacquer. (Dr.J, it's time to step into the new century!)
The stuff is outdated & obsolete. Lacquer drys by evaporation only. When the solvents leave, it shrinks. I continues for years, weakining the film.
As for single stage(catalyzed) vs. base / clear, it's personal preferance. I like single stage for solid colors(sometimes), base clear for metallics. Either can be flow coated for "show" finisnes.

Flow coating is when you shoot two or three coats of clear, let it cure, sand it down. and put on two very wet coats. Sand and rub that, and you have a finish like glass.

Anytime you are spraying a catalyzed product, DO NOT spray dry. Always shoot at least two coats. If catalyzed products are shot too dry, they will fail to cross link. If they don't cross link, you don't have calalyzation. When you shoot more material over them they will lift.

Don't exceed the re-coat times. You have a "window" that you need to stay in. Too soon and you'll have solvent pop, wait too long, and you'll have delamination between films, or lifting. The re-coat times will be in the P pages.
FWIW, the majority of factory delams were caused by lack of UV protection in the materials(thats what happens when you by cheap materials on "low bid")

Buffing, I like to sand and rub, within two or three days max. Any longer and the material gets too hard. Harder to polish, making it easier to burn thru.
well that's all I can think of for now. I think safety was covered in Tmans respirator post. I will add, along with a good respirator(that fits) were gloves, a paint sock, or hood, and a shoot suit.

[lowsquire]

All this is great info,Im a little confused and it may be because of terminology, but base/clear coat sysems are a 2pack product right?with a hardener in the clear?
and arent these a urethane paint?
theres a post in here thats got me all confused about this.

[Tman]

Base/clear is a flat basecoat with the gloss added by the clear.

What you call 2 pack is the Primer I sprayed, urethane and catylist ?

[flyin'eye]

Lots of good info here. I was thinking my popping problem had something to do with flash time, but now that it has been brought up here, I'm betting lack of airflow has a lot to do with it. One box fan probably doesnt cut it. Every time I shoot a car, I learn something new.

[chopolds]

Lots of great info here, beginners take note!
You shouldn't be afraid to use the new paints, they are much better than in the past, or on those flaking factory jobs. I have been using BC/CC for over 20 years...since I first used a "Mercedes" paint, to paint a customized Caddy. Couldn't get used to the base coat drying so flat, I kept trying to load the paint on, to get it to shine. Then I learned that it was supposed to be that way!
Anyway, about longevity, I painted my 55 Olds with the "new" House of Kolor URETHANE candy, when everyone was still using lacquer, back in '86. True it was tougher to get used to, after using lacquer for all those years, but it was worth it. The car still looks presentable, and it spent 5-6 years in an outside, unheated garage, and then a couple years in my driveway. The color is fading, more than anything. Can you say that about a lacquer candy paint job? And not in California weather, either, NJ's four seasons.
Last, but not least, please take note of the cautions of using these paints. Use a great respirator, throw it our ofter one paint job. Or better yet, use a fresh air system. Use gloves, and protect your face, eyes, and skin, too, as those nasty additives can be absorbed though them, as well as your lungs!

[overspray]

BRAVO!!! Finally a post on paint with excellent input and information. I'll give a tip of my painter's mask to all of you. overspray http://www.jalopyjournal.com/ubbthreads/images/graemlins/laugh.gif

[born2late]

another tip for you guys that fight dirt in the paint. This works especially good when painting fiberglass parts. After you do the final tack rag and blowdown routine, try a PPG product called DX 103. It is a blend of water and isypropal (sp) alcohol. You can make your own but I forget the ratio. Anyway, give you whole subject a mist coat and it will kill the static electricity you caused with all the cleaning and rubbing as it evaporates. This keeps the dirt from being attracted to the part. Shoot color as normal. All you gold chainers painting your glass "kit cars" will love it!!!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Roothawg]

The box fan is ok but you have to leave it on while it cures out. Most guys kill the fan after the overspray settles.

[Roothawg]

Here's a question for debate.
I was talking with my PPG rep and he told me that if I wanted to flow coat my cars, I could spray 2 coats of clear and colorsand with 400 grit. He says it doesn't matter the grit as long as it is somewhere in the range of 400-800.
He says that give it more teeth to adhere to and then you can hit the last coats with 1000-2000....whatdya think?

[Tinbender]

Yeah Root, it seems course, but it works. Personally I like 600 to 800(less chance of cutting thru)
One more thing, don't finish you final prime past 500 wet. I see some guys go to 1000. I've seen it peel too!

[Roothawg]

Tinbender, I always wet snad to 400 and then seal with DP. Then spray topcoat after it kicks. This is all self taught and a lot of questions to various paint reps over the years.
I have a PHD from the School of Hard Knocks.

[MercMan1951]

Here's another one of the benefits to a BC/CC paint job:
When you have to repair an area that is damaged, & you have to "blend" into the adjacent panel.

I always used 800-1000 grit on the entire adjacent undamaged panel (assuming it is a BC/CC car to begin with). You can fade the base into the next panel (usually about 1/2 way into it), then clear everything (repair and undamaged panel) all at once. If you're good with a gun, you won't be able to detect where the "new" paint was blended into the old...a seamless repair. Old urethanes and lacquers were a bitch to do this with, if at all. That's why you see "old" cars running around with a door and fender not quite the same color. It was pretty much a panel by panel deal, and if the repair panel was a slightly different color, bingo...a detectable repair.

Theoretically, if you had an entire (BC/CC) car that had lost it's luster, and had minimal paint chips, you could 800 grit the whole car down (it will look like a white powder fell all over the car), and then re-shoot another one or two coats of clear over it to give the paint some new life. I never did this, but I suspect it has been done...especially by used car dealers http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif

I have seen some cars, that when the sun hits the side dead on, you can see where the painter stopped his fade...shame...shame. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif There's a lot of bad bodywork out there...

[Fatchuk]

I have really enjoyed all the information being shared here..On the question of dirt and tyvek suit...what is the tyveck suit...is that just what those white jump suits from the paint store sell ...and a cap could that help a lot really .I am just more interested as I give my self a real good going over with an air gun and never wear a hat...or a suit all that often..and I do have a problem with dirt.....another thing I have some questions about that has not really been talked to much about..fans...the fans in my shop are across from each other rather at the end of the booth....lets see try this...the filtered door is to the right 1/4 panel the filtered area is approx 8' by 3'..on the left 1/4 I use a slower furnace fan squirl cage type nice slow stedy speed to keep air moving...left fron fender has an 18" fan that has enouhg air movement to hold the shop man doors open ....booth is painted siding steel .with about 12--8' flourecent lites I wash the booth every paint job...drop a chain over the axel .wash and wipe the car ..tach it and spray.....following the manufactures instruction...and still I get dirt.....gawd I hate dirt specs in my clear ...anybody else have this problem or overcome yet ....fatchuk

[Tman]

Very cool, I learned a lot. I would call my wheel painting experiment a success. We could have went with a couple more coats of clear but I am going to leave them the way they are. I cant wait til I start squirting the frame and body. I am using a high build primer and the mentioned Single stage Urethane.

[daddylama]

since changing over to a positive-pressure paint booth, my dirt problems have faded quite a bit...

"positive-pressure" as in: filtered air is forced into the room at 4 vents on the front wall... the back wall has exhaust filters. Air flows from the front to the back.
The airflow is OK (could be better, but need a larger blower), the overspray is noticably less than before, and less dirt/dust issues.

[Humboldt Cat]

Good post!
[ QUOTE ]
Urethanes require heat and airflow to properly cure. With out it, you can have delamination later on.

[/ QUOTE ]
This may sound dumb, but does the outside heat factor count, if done in a professional shop? I'm prepping it myself, but plan on having a local shop lay on eurathane with a clear coat. In December, if ready. In the Northcoast December.

[Fatchuk]

Why would you use a clear coat over a urathane.I have always thought that would for sure result in a delamination of the clear due to trapped solvents....Base is flat and the reduction of the product 100% makes sure the solvents evaporate quickly for the clear application...but the urathane takes about a day for the solvents to evaporate so isn't that just asking for a problem...if you spray clear over urathane...I have mixed a little clear in my last color coat once in awhile with no seemingly apparent problem..fatchuk

[Reverendcolin]

I'm more into base coat....period. Usually sprayed with HVLP outside on a not too windy day. Dust and bugs add a rustic flavor but can be sanded out.

[customcarpainter]

On my next to last coat of base I always let it flash for approx.30 minutes,then I'll lightly sand the entire area that has been painted with 600 grit to remove the dirt specks that have found their way into the paint,then tack the surface clean and shoot the final coat of base.Try it,makes for a cleaner finish as well as a slicker finish.

[born2late]

On the shoot suit-try it with all else the same and see how much better it looks. It only takes one piece of hair in a light color base clear job and it will make a difference in that. Plus it keeps the fumes off your skin and hair. I agree with the 500 grit final sand on the primer-dont go finer it'll peel. Another trick for the old timers-keep a small piece of 1200-1500 in a coolwhip bowl full of DX330 or 440 in the paint booth. If ya get a dirt speck in the sealer you can wait 10 minutes and sand it out with this paper. The 330 lubes the paper and will evap. with no residue. Wipe with a tack rag quick and base. Works in solid base colors to but not metallics if on the last color coat before clear. Anyone ever pull a bug outa the clear on the last coat, mix up some over reduced clear, turn the pressure and the fan down to nothin' and melt the marks the damn bug left? That ones fun-impresses the chicks!! How about chasing a run down to the bottom of a door with lots of clear and cuttin off the drips in the morning. Never tried it myself but have seen it done--saves some cuttin' and buffin'. I could go on and on. When its gotta go home the next day, youre bound to try anything!!

[lownslow]

bc,cc is THE ONLY way to go ........way more durble than single stage paint too.......i was told by a painter a long time ago when i was first getting into do custom work...'' real painters use base coat clear coat '' ....i love it and yeas i have sprayed my fair share of single stage as well .....urethane , acrylic enamals too. but base / clear is by far the best way to go ......at least thats my story and i am sticking to it..............

[hillbillyhellcat]

I am just learning how to do paint and body myself but an redoing my '72 F100 in it's same original color.

I originally had planned on doing it in one step but have learned that doing a metallic paint job in base/clear is a lot more forgiving. Instead of trying to get the paint on even so the metallic doesn't pool up and still get it to shine, you can pretty much just shoot it on and the clear does all the work.

I have the bed all done and in etching primer and hope to have the cab in primer by Friday. I've been working on it for 4 hours a day for the past month.

Omni mades a very affordable base, It was $150 a gal in comparison the $250 PPG wanted. I am going to use the PPG clear, however, as it's a better, more durable product and will probably be easier to keep from looking dry.

It's pretty enjoyable to do the work and I am learning something. It seems like I want to paint everything anymore. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif