Thinning Clear
 

Ok you jet boys always have the slicker than snot birds. What is the secrete to thinning clear to reduce the amount of buffing required. Our Dupont guy says HELL NO but I have read for years about guys doing it.

RE: Thinning Clear
 

Not a painting expert, but from what I've been taught by a local guru I think that thinning clear vs buffing has no relationship.

RE: Thinning Clear
 

I thought that thinning the clear allowed it to dry much flatter so you did not get the orange peel

RE: Thinning Clear
 

orange peel will always happen to a certain extent .. it needs to be sanded out with finer and finer grit paper, and lastly polished.


Wojtek

RE: Thinning Clear
 

The DuPont guys tell me the same thing and we buy their paints for our model shop. They are not going to tell you to thin it because if there ever comes a problem then someone would hold them responsable. DuPont formulates their paint for automotive use. We thin DuPont Chromabase with regular old Home Depot brand Acrylic Lacquer thinner...Tthe Nitrate based stuff and it works flawlessly. Thinning clear allows it to flow out more providing a smoother finish. If the clear is not thinned enough then it tends to stay in place more. Orange peel can be minimized by turing up your air pressure to atomize the droplets better...this in conjunction with thinning your clear. To get your absolute best mirror finish, as Wojtek said, you need to sand with finer and finer sandpaper and then a final polishing. Applying a coat of clear then wet-sanding with 1500-2000 grit sandpaper and then applying another LIGHT THIN coat of clear will also give you a very sweet finish with hardly any buffing to do. LGMGraphics can provide more input on this probably better than I can.

Les

RE: Thinning Clear
 

Thanks Les. I knew that buffing still needed to be done but I have talked to guys for years that said they thinned out the clear. Guess I will give it a shot. How much do you thin your Dupont? Are you shooting Chroma Clear?

RE: Thinning Clear
 

With PPG I use three parts reducer (thinner) to one part clear. Apply a very light tack coat, it should just be visable, but not glossy. Let this dry a few minutes and follow up with two wet coats. Set the paint flow and your speed so that it takes a couple of quick passes to get a wet gloss coat, this will reduce the chance of a run. With PPG, depending on the air temp you want to sand it 12-24 hours later. If you wait more than 48 hours it will get hard enough to make it hard to get it to gloss back out. If you did a reasonable job you can start sanding with 2500 grit. Try to find some McGyweyers (sp?) sand paper, it cuts much smoother than 3M. Be carefull sanding, when you thin the clear this much it is pretty thin, but light. You can then follow up with some 6000, 8000 and 12000 micro mesh, followed by polishing compound, or go straight from 2500 to compound and put a little more elbow grease in.

When sanding always sand in one direction, do not sand in a circle, the scratches will be more visable and harder to polish out.

I would think the process with Dupont would be very simular.

Hope this helps,

Steven

RE: Thinning Clear
 

thin it 200% to 300 % and do some test shots. Flows like glass, but is thin and requires several coats.

RE: Thinning Clear
 

already been buffed out ! I will try and find out from him what this clear is exactly. Chip still buffs and polishes it to get even more shine out of it, but that’s just him :D


hows these for a clear coat ( note the reflections in the paint ! ) ??

Voy

RE: Thinning Clear
 

I've always used Sherwin Williams automotive clear (3 Part) mixed as per specs and sprayed with a smaller automotive gravity feed touch-up gun, I've never had the orange peel affect (I'm no expert either) I've found that once you play around with flow, air pressure, movement and right tempature you will be able to get a glass like finish.

Hotspot on a cloudy day (after some playing around this was my first attempt at painting...no runs:D)

Angus

RE: Thinning Clear
 

We use DuPont Multi-Use Clear 7900S which is a 3 - 1 ratio. It flows out like a charm. At work we don't typically have to thin it much more than is recommended. The hardner that is used with it is a Hardner/Reducer. If we are spraying through an airbrush we typically thin anywhere from 50 - 90 %. At home I have PPG Concept DCU 2002 Clear and I thin that up to 100% giving me a 1 -1 ratio of mixed clear and thinner. They are both great clears.

RE: Thinning Clear
 

Understand the concept of thinning the clear coat is not to reduce buffing, but to reduce the weight of the paint job overall. I reduce clear an average of 150 - 200% when I shoot. I reduce the colors of a base coat/clear coat system between 100 - 150%. I reduce single stage colors the same as clear, 150 - 200%. The end result is I can paint a Bandit with a weight gain of under 1 pound this way, and that includes primmer. I have a tutorial that I believe Todd Whitkoff has on his site to walk you through it. It is at www.dreamworksrc.com. I wrote this about 4 years ago.

Buffing comes from multiple levels of sandpaper and buffing compounds. Steve Elzy mentioned the best approach, period. His paint jobs show it as well!

If you need some help shooting paint over in Rantoul, I would be happy to come over and help you out. Give me a yell.

RE: Thinning Clear
 

If the only reason was to save weight then I guess I will not reduce as I need the nose weight and this is a cowl LOL. I always thought that the thinned clear would flow out better and reduce the orange peel.

RE: Thinning Clear
 

I use a DuPont product called "Blender" (its primary use in automotive is to melt in a spot touch up on the clear coat). Using DuPont 7900 with a light base coat on the first pass and then another coat of clear.....then 80% Blender added to the gun and make your final pass. Outstanding gloss....orange peel disappears...no buffing required if you are careful and keep it clean and light. I really believe Blender is mostly lacquer thinner, they just don't tell you that at DuPont:D

Richard

RE: Thinning Clear
 

David Reid (and John Redman) recommended to me a long time ago 200% reduced, and I gradually worked up to that amount with the Spies Hecker automotive paint I am using, and it works great. You can't go heavy with the coats, but you shouldn't be doing that anyway. I wasn't as concerned with the weight reduction as I was with the reduction in orange peel, and using this method the clear flows out like glass.

Antony

RE: Thinning Clear
 

My first attempt at getting back into painting worked out quite nicely......most of my previous painting was 20 years ago using Hobbypoxy......

I just added some hi-viz red/orange to my KC using John Redman's technique with 2021........I am not sure of the % of thinning........factory specs for 2021 are 4 parts clear:1 part activator:1 part reducer.......I ended up using 4 parts clear:1 part activator:4 parts reducer, whatever % that works out to be....the mixture by volume I used was 2 oz clear, 1/2 oz activator, and 2 oz reducer....I mixed them together and let them activate for 30 minutes at about 70F ambient....I got minimal orange peel on my first wing but then by cranking up the pressure about 5 lbs on my HVLP gun, the second wing was near perfect.....

The wing stripes and tips were originally dark green metallic PPG base and clear......For the new base color, I lightly sanded the green with 1200 paper, applied 4-5 light coats of SEM primer until the green was no long visible, wet-sanded with 1200 and then 1500 paper, re-masked and sprayed on the zinger color with Plasticote, rattle-can, flat, hi-viz red/orange(it's compatible with PPG....just be sure to mist on the first 2 coats of clear very thin and let dry for about an 1/2 hour before laying on the 2 coats of thinned, wet clear.....otherwise, you can get microbubbling when the wet clear coat hits the virgin Plasticote)......I let the Plasticote, dry and shrink a bit in the hot sun for about 8-10 hours, lightly sanded the edge, and then did the clear....Plasticote makes a wide variety of cool colors, including metallics....only $3.99/can locally......it sprays nicely, but got to be sure to keep the tip absolutely clean by soaking in laquer thinner between uses.....otherwise it will spit......

18 hours later, I sanded with 1500 3M paper on a hand held, air-driven 3" orbital buffer, then with 2000 paper......then orbital buffed with the Fine Cut 3M cream John recommended with terry cloth on my buffer...it took about 3 applications of the cream to get a nice shine back...then, finish polished with the 3M polish he recommended..... finally hit it with some Mother's wax.......

3M makes a nice double sided hook and loop spacer for between the hook and loop on the sander/polisher and hook and loop back paper......it is made of light foam and allows enough flex in the sandpaper surface so you have less chance of cutting through the clear over curved surfaces....


Tom

RE: Thinning Clear
 

The guy I get our paint from told me the same thing about the blender. He told me to use about 80-90% reducer to 10-20% clear mix somewhere in there, it doesn't have to exact. This was also using the DuPont 7900S clear. Lacuqer thinner also works the same.

RE: Thinning Clear
 

ama234 , Do you mean DCU2020 clear? I have used this and it works great thinned. I have a question while we are on the paint topic, I am building an all White Comp. ARF Flash right now, I anm going to do a Navy trainer scheme, Orange ,White, and gray. Would you recommend that I use single stage paint for the Orange and gray, and just leave the white like it is now, or should I use Basecoat /clearcoat for the Orange and gray, and just shoot the whole plane with Clearcoat. Thanks for the help, Jack.

RE: Thinning Clear
 

What size nozzle are you guys using with the 2021 reduced by 100-200%? I've been shooting with a 1.3 with the standard 4 to 1 mix plus 1 reducer. Still learning and would like to be able to shoot with a 1.00 or smaller.

David S

My current project:

RE: Thinning Clear
 

On the reducing of the clear for spraying for our pruposes. PPG will tell you to not reduce more than 10%. this is to maintain the molecular base and strength of the clear coat. Reducing it by 150 - 200% only mkaes it spray on much easier and thinner, it reduces the weight by a bunch. the end result is we don't have the durability that the clear coat does on your car fender. But my theroy is most of us are not driving our models down an interstate at 75 mph. We don't see the rock chips your car does.

It is very easy to flow the reduced mixture out like glass and it flashes off very quickly. What I have found oevr the years, is the less reduced your clear is the more perfect the environment needs to be when you spray. I have painted in rain storms, high humidity, cold weather (30 - 40 degrees) and 100+ degree days as well. I have never had a problem and I have always been pleased with the results.

Reduce it down with the appropriate reducer and you will not be sorry. Please note that I have said to reduce it and not to thin it. They are not the same thing. Once again, ensure to use the correct reducer for your brand. Download the tutrorial I wrote, bottom line is it works. At lease I have yet to get a phone call from anyone saying my paint procedures screwed up their jet.

Happy painting.

RE: Thinning Clear
 

No, I am talking about Concept DCU 2002. http://www.ppg.com/refinishftpsite/docs/p-200.pdf
I must apologize but I do not know how the Comp. ARF kit comes. If it were me and it came with a nice bright white, I would simply paint the orange and grey using a base coat and then clear the entire model as you more than likely are not going to have the glossy lustre (sp?) with the white unless it is clear-coated.

Les

RE: Thinning Clear
 

From what I understand after many trips to various paints stores and bending many ears, John you absolutely correct. My current supplier here in AZ had something else to add. The paint store guy told me that he couldn't, as a PPG dealer, recommend reducing more that the factory specs due to EPA concerns. He did however, tell me what some of his !QUOT!best customers!QUOT! were doing.....basically reducing the heck out of the stuff! So, I think that durability and regulation dictate the reduction rate for the pros splashing the paint on cars..........

Tailwinds,

John

RE: Thinning Clear
 

Hey guys, my shop uses PPG only and if I may I would like too add to the good info here, when you over reduce use a slower hardener than reducer this helps against dye back as the reducer has more time to evaporate before it hardens, and traps the extra solvent in it, which then would need to be buffed to bring the high gloss back, hope this helps.

george

RE: Thinning Clear
 

The "pros" don't "splash" paint on cars....we leave that to the "choppers".

So, you guys that want/apply multiple colors using this method of over reducing the clear to ommit buffing don't mind seeing or feeling the transition of colors under the clear???

If you are seeking gloss and durability, why not manipulate the product you're spraying with reducers and hardeners already supplied by the manufacturer?? For example: if you're spraying with PPG 2000,2001,2002,2020,2021 clear and you seek a "high" no buff gloss, slow everything down. Use a slow hadener, stay away from DCX hardeners and use DU5 or DU6. When choosing a reducer go with DT895 or DT898. The longer the clear is allowed to "flow" higher gloss will result...DU6 with DT898 mixed in any of the clears mentioned earlier will flow out nice.

I spray clear and single stage colors with a SATA95 w/1.4 needle,tip and cap. If you're spraying with an HVLP gun, refrain from using a cheater/regulator at the gun. If you restrict the air at the gun you've just turned your High Volume Low Pressure gun right back to a coventional gun, rendering the advantages of an HVLP gun useless. Gloss and orange peel can also be controlled at the gun, i.e. fluid volume, air pressure, fan pattern and speed. I spray clear "wide open", fluid opened at max, fan pattern at full and air pressure (on the gun) at full. I spray 6 to 8 inches off the surface and I move faster than a rabbit in heat. Most aren't comfortable spraying so close and fast...I've been doing this for right at 20yrs and this style works for me....but I still buff as I like it all to look like it's under glass. I put 3 coats on and sand 1 1/2 to 2 off.

As far as buffing goes, I wrap a piece of 3M 1500 around a Motorguard black and grey sanding pad and sand till the surface is flat...no pattern, no orange peel and no transition of colors. Hand buff?? That's CRAZY....Snap On variable speed buffer with a 3M double sided wool pad and 3M Perfect It Micro Fine compound. Then finished off with a 3M foam black pad and 3M Perfect It polishing/cleaner. If you're gonna wax you should give the clear at least a week to finish burning off solvents. Waxing "closes" the suface and COULD cause solvent pops if the clear hasn't had time to burn off all the solvents.

Base color...just wondering. Why would you want to over reduce a base?? Most base colors are 1/3 to 1/2 pigment with the remainder being binder which is actually a "base" clear. Over reducing the base would thin the pigment meaning it would take more material to cover.

If weight is your main concern, start shaving it from the begining. If you need to cover body work, prime with a LOW BUILD primer only on reworked areas...not the entire aircfaft. PPG has a epoxy primer/sealer called DP, it comes in black, white, gray and red. DP has some "build" to it, so if your body work is nice you can actually use it as primer. Let's say you want to paint your aircraft red...DP in red, now the surface is red, so now it takes LESS base to cover the surface. You've just saved weight by reducing primer and base weight.

Just my 2 cents.

RE: Thinning Clear
 

What you're referring to is also called blushing isn't it? Or is this something else?
Thanks,
Les


Hey Fat boy,
Thanks for the book! Lots of great info in there. We use DuPont at work but they don't have a white primer. I think we will look into PPG for that. Thanks again...good stuff you added.[sm=thumbup.gif]