Clearcoat Reducing
 

Hi Guys,

I've never use auto clearcoat and have a few questions. I'll be painting my Super Reaper with Createx Auto Air water based acrylic paints and clearcoating with Dupont Chromaclear 8500s high solids clear coat. The colour selection with the Auto Air is excellent with pearls, irradescents, and chameleons so I hope this technique works.

The instructions on the clearcoat say to mix 8-2-1 which means that it's only reduced 9%. In searching this forum for answers to this question I've seen recommendations to reduce 100 to 250 % !!!
Thats 10 to 25 times as much reducer as the can says.

So guys, any comments ?


One more thing !

Do any of you guys clearcoat between colour coats to prevent the tape from lifting the base colour. I was thinking of painting on the Createx and giving a light coat of spray bomb clear only where I'm going to mask and so on....

Don't reduce more than 15%
 

Don't reduce much more than the manufacture suggests. Your hang power goes to hell--------sags-----I use PPG Omni clearcote the low cost PPG solution and I would think other brands will be similar--- do a test job and test the gloss over and hang then you'll know for sure-----
Lee----

Re: Don't reduce more than 15%
 

Lee, I have to respectfully disagree. I can only speak for PPG high end clearcoat. I have never used Omni, nor have I used Dupont clear. Using the DC2021 Clearcoat, I reduce 200%. It flows out very nicely, and doesn't sag unless you get heavy handed, then any of them will run. I figured this out one day while talking to Bob Violett about all the work involved in getting a really nice finish on a jet. I had been wet sanding the entire airplane through 2500 grit, then buffing and finally hand rubbing every square inch of the plane to get a really good finish. BV told me he never sands or buffs his planes. I was surprised, because his stuff really looks good. He recommended that I reduce the clear 150-200%. My jaw dropped. Previously I had been reducing 10 to 15%, and could not get rid of the orange peel without sanding. I couldn't imagine reducing 150% or more. At first I tried 150%, then 200%. The 200% did the trick. The clear flows out beautifully with no orange peel at all. You are also able to put on a much lighter clearcoat with the reduced clear. It doesn't take nearly as much clear as it did before. I use the Walcom STM with the 1.0 and 1.2 tip. This is a great gun that paints like an airbrush up to a 4 inch fan.

This is what works for me.

Dennis Lott

Clearcoat Reducing
 

Thanks Guys !

I knew I'd get differing opinions ! I also have the Walcom STM HVLP 1.2mm .

Dennis,

Do you have any setup or usage tips for that gun ?

I was pig headed
 

I would never reduce more than maybe 25-40 percent. Orange peel, uneven gloss, basically what Dennis said


I did a repair on a large panel and finally reduced over 100%, probabaly 150.

Night and day difference, I felt so stupid for not doing it sooner.


I have seen guys that can spray the 10% reduced mixture and get good results, mere mortals like myself....use the 150% mix

Just my opinion, I need every unfair advantage I can get while finishing

gentelmen please
 

each finish you have used is a diff. animal in its own right's,the key to getting a great finish with any paint system is a test area, go to the wrecking yard and grab a car hood, leave it out side when not painting, but , bring it in and stand it up against the wall while finishing a project, you don't need to paint a very big area for your test, sand the hood and prime with an epoxy primer, that way all finishes will bond.

Fine tuning
 

I almost always set the air pressure to the 28.6 top of the green. Set the needle and fan pattern to suit your style of painting. If I am using it as an airbrush, I dial the pressure down and adjust the needle as needed to get the spray pattern I want. The gun is so easy to paint with, you won't have a problem. I usually make a couple of passes on a cardboard box, or whatever is handy, just to make sure the gun is set right before shooting the plane.

Dennis

Re: Clearcoat Reducing
 

If you are using the 3M blue tape, and don't have really sharp bends that cause the tape to tend to lift, and don't go across control surface hinge lines, then I wouldn't worry about clear between coats. If there is any chance of a slight lift in the tape, spray a very light reduced coat of clear. Since you are using differing types of paint from different manufacturers, definitely do a test panel with colors and clearcoat applied before putting it on the plane. I am a strong advocate of using a paint system, i.e. one manufacturer. I have had problems mixing paints from different manufacturers.

Dennis

Clearcoat Reducing
 

Actually Deniss, I was concerned about the paint that has the masking on it coming up when removing the masking. Someone suggested that I clearcoat and then mask to stabilize the surface.

Reducing
 

.Hi, I would like to let you know that I also just started using auto paints also and went threw this same problem.I would just try it out on a test sample first, But I did follow the manufactures directions the first time and the clear came out very bad the next time I sought professional advice, and I was told to mix 3 to 1or even more, he uses this mix ratio on different types of clears and let me tell you its a must... you should only need 2 coats one tax and one flow ideally, but others sand and clear again so their are many different techniques of ways of doing the application but to the original post I agree that a mix of 150 % or more... will give you the best results for a beginner but again try it first on a test sample so you will feel 100% sure. Good luck

Clearcoat Reducing
 

I reduce my clear to a minimum of 150% and usually to 200 % I am also using only PPG 2021 or recently the PPG 2060 Flexed n Flat on my Phantom. It flows fantastic and will NOT orange peel or sag no matter how hard you try to make it do it. (With normal painting techniques.) The other added benefit is that you can get away without rubbing, sanding and buffing the clear if you want.

David Reid

reduce that sucker
 

Yep -- these guys are right on with their reducing advice. I have used the Martin Senour acrylic enamels on several projects and have to say that the more you reduce, the better the clear looks -- i.e. no orange peel. Of course this also means you can't go heavy handed on application, but that should be a given anyway. Heck I accidentally sprayed a bug into a finish last week, immediately removed him with tweezers and the clear flowed out perfectly!

(Didn't mean to make this sound like a "fish story.")

Antony

Clearcoat Reducing
 

Darn reducer..... Where I live VOC compliance is a pain and last time I went to buy clear, they legally could not sell me a compliant reducer for the PPG DCD25 - and we can't get the 2020 clear(good stuff) either. I shot one plane with no reducer. What a pain! But, I sprayed one yesterday using the regular PPG base coat reducer. I didn't know if it would work but seems to be fine (clear isn't peeling yet <g>). I too have found that reducing the clear quite a bit is necessary to get good results. The clear seems to dry a lot faster on the surface than base coats and is tackier, making thinning necessary to shoot it well.

I shot this PPG clear (on the below pic) over Sickens (Mercedez Benz paint :) ) and it worked well... The clear was reduced about 75- 100% (I know, it's not a jet - one's coming soon though...)

-Michael

Paint
 

Mluvara,
I am glad to see that someone else is using sikkens paint. I think it is a great paint especially since you can mix and just use without worrying about it setting up in the can. I painted my bobcat with the sikkens base coat and used ppg clear and it came out beautifully. The only thing I would change is that I reduced my clear by only 100% and it came out a little thick on the plane. Next time I will reduce it by 200%


Pat

reducing
 

I convinced that the clear coat should be reduced.
What about the base coat? Is it being reduced as per instructions or reducing it more.

Clearcoat Reducing
 

Bob,

I mix the base coat a little more than 1:1 (more reducer) mainly because I spray with an HVLP gun and you need the paint to be a little thinner.

DR

reducer
 

Thanks David

Clearcoat Reducing
 

Bob,

I reduce the PPG DBU and DBC basecoat up to 150%. If you don't get a smooth application at 100%, don't be afraid to reduce to 150%.

Dennis

Clearcoat Reducing
 

Hey Marc,

Be sure to post some photos of that Reaper when you are done. I flew mine the other week for the first time. Nice and easy to fly.

My only problem was a lack of elevator authority during the flare on landing and I bent the nose leg as well a bit of a bounce. I was running the cg towards forward limit and probably landed with a bit too much fuel on board. The cross-wind was starting to gust and I figured I may as well put it down during a relatively calm patch.

I have since shuffled the back closer to the 53cm mark that the instructions call for and mixed in some elevon with the canards on up elevator. I'll let you know how it goes.

I have also added a bit of shock absorbtion on the main gear to try and reduce the bounce. I'll post a photo tomorrow and see what people think of what I have come up with. I was reluctant to just silver solder a 4-40 rod between the legs as a spreader bar. Then it would have no give at all.

Regards,
Garrett

clearcoat
 

Guys, I too have been experimenting with the PPG line of clearcoats. Im doing a ziroli bearcat in Rare Bear colors from 1985(purple/white). I have done some cowlings for aerobatic birds in ppg, but never a whole airplane. So far I have applied the base coat on the fuse along with the purple stripe and Im now ready for clear coat. Am I to understand that you really reccomend thinning 200%? If this is so, how long does it take to dry with the reccomended activator? Also, say if I was mixing 1 oz of clear, how much activator/reducer would be needed in oz?
I know its not a jet but the paint is the same, any help will be appreciated.
Pics of the bearcat are on this page:
http://www.homestead.com/evoshangar/skunkworks.html
Thanks,
EvanQ.

Do a test first!~!!
 

EvanQ,
Reducing the base cote will only make the color less opaque. Be careful reducing the clearcote as much as is indicated above. Remember when using PPG the clear is mixed 1:1 with the activator first. Then you can safely "Reduce" that mixture up to 20%. If you want to experiment with a greater reduction do so on a test piece please. Reducing will make the Clear thinner and it will sag easier, and might even get brittle-----
Lee ---------

Clearcoat Reducing
 

Lee,

I have to disagree with you. I have been painting with the PPG clearcoats particularily the 2021 for several years now. Since I went to the higher reduction levels I have YET to have it sag on me. I can lay it on where it looks wet and it won't run. When you reduce it to this amount you are laying less clear on per coat. The solids in the clear are what causes it to sag not the reducer. If you have selected your reducer properly (according to the temperature range that you are painting in) then the reducer evaporates very rapidly, leaving a fantastic clear coat finish. The other thing that putting on thinner layers does for you is it makes your painted finish come out lighter. Never has gotten brittle and I just can't get it to sag.


EvanQ

Trust us on the amount of reducer and spray it on your plane. I guarntee you will be extremely happy with the results. Mix it per the instructions for the clear and catalyst then add 200 % reducer. In the case of 2021 it is 5 parts 2021 to 1 part DCX 61 then add 12 parts reducer. I use DT 885.

200%
 

Evan, I might add that you need to lay the first coat on VERY lightly as a tack coat. Let it tack for 3 or 4 minutes, then lay on a light final coat. It will flow out to a wet look, and won't run unless you get carried away with it. In 10 minutes it will be dust free.

The base coat flows out very nicely when reduced 150% with minimal sanding before clear. What David and I are recommending works well with PPG paints and the Walcom STM gun set to the top of the green on the regulator.

Good Luck,

Dennis

Yeilding on this one----------
 

Hello Daivd,
I'm going to yield to your experience on this one --------- I only have used the less expensive version of PPG the Omni line. I will admit what you say makes since, and I will try higher reductions on my next bird, but I will still test it for myself first. I am stubborn as a mule, kinda like I have to see it for myself and then sometimes I still don't believe it.

Evan, no reason not to try high reduction in a test mod, then if you like what you see, shoot it for keeps.

Don't pay any attention to my reference to being brittle as that creped up in my head from the old lacquer days and adding flexers------ this new generation X'er stuff probably doesn't react negatively to more reducer------- David must know he is willing bet the farm on this one -----------
Lee------

Clearcoat Reducing
 

Dennis,

The PPG paints I have state that you should NOT sand the base coat. Please help me understand how and what grit you use when you sand the base. Also, which base are you using?

Thank you,

Mark M.