what am I doing wrong and how best to clean this up.

Thin your paint a bit.   Thinner paint will spray at lower air pressure.  At  higher pressure paint may be blown under a tape edge.   Also spray away from the tape edge, from tape onto plastic as opposed to plastic into tape.

Master Blaster

I thought I had carefully taped and made sure the edges were firmly pressed in place but .........

Including the above suggestions, here's an additional step.

After masking, shoot a layer of future over it and let it dry.

Then apply the paint.

When you pull the (low tack) tape off you should have a nice clean demarcation.

Been there and done that.........   many times.

Master Blaster

shoot a layer of future???

 

Future Floor polish.  Though I think now it's called Pledge Floor Gloss (Though I think there will be plenty of people to correct that if I'm off-base)

Count me in with those who say you put your paint on too heavy.  Go with light passes until you get opaque coverage.  Don't go beyond that and keep flooding paint onto it in coats...you're not painting with a spray can, so use the airbrush the way it was meant to be used...to give you thin, light coats of paint that don't run, sag, or bury even the finest of details.  There's no need to be putting clouds of paint into the air like what you might see in a lot of airbrushing instruction videos.  Those videos always make me cringe.  Your paint should be thinned to the point of running down the side of your mixing cup like 1% milk.  Shoot it at about 20PSI, and you won't need any extra steps to keep it from creeping under your tape.  If its creeping under your tape, its going on too thick and too wet.  Piling more and more layers of stuff onto the edge of the mask is only going to complicate the unmasking process later.  You can easily end up with flaking and chipping that way.  Remember, when painting scale models, less is more..."just enough" is enough.  

And to answer the second part of your question, you will need to strip the whole thing and start over, I'm afraid.

Bill

GMorrison

And to answer the second part of your question, you will need to strip the whole thing and start over, I'm afraid.

Yup.  Stripping to bare plastic and starting over is the best way to clean up the mess.  The safest stripping method I have found so far is isopropyl alchohol and a cheap electric toothbrush.  It will strip every single drop of paint off your model and won't hurt the plastic.  It works its best if you're able to at least partially submerge the part being stripped in it, but it also works in situations where that isn't practical.  A Q-Tip just barely damp with isopropyl alchohol also makes a great alternative to scraping paint away from areas you want to apply glue to.  Its much easier, quicker, and doesn't accidentally gouge your plastic.  Lots of other good stripping methods out there, but DO NOT use oven cleaner (still popular for some inexplicable reason).  The chemicals in oven cleaner will react with the styrene, alter its molecular structure, and you'll end up with a piece of plastic that is now much more brittle than it was before.

Eaglecash867

Count me in with those who say you put your paint on too heavy.  Go with light passes until you get opaque coverage.  Don't go beyond that and keep flooding paint onto it in coats...you're not painting with a spray can, so use the airbrush the way it was meant to be used...to give you thin, light coats of paint that don't run, sag, or bury even the finest of details. 

thanks for the reply - these light passes are we talking about doing them all in one session or allowing the paint to dry between them.  I have seen demonstrations of both ways.

You're going to want to do your light passes all in one session.  There's no need to allow drying time between them because they are going to be extremely thin.  The first pass with your second color should still show lots of the first color through it, the next pass a little less of the first color, the next pass a little less, and so on until you get opacity of your second color.  You can also scribble fine lines with your airbrush to give varying opacity, showing more or less of the base color, to give your model's paint work a worn look like you might see on a starship...or like what you might see on a military aircraft.  That will come with more and more experience, but in the mean time, put just enough paint on in light passes for the color to just reach opacity.  No need to go beyond that...no need to come back with multiple coats of the same color.

Here are a couple of examples of really fine paint masking, with nice sharp, clean edges.

F-16 canopy with a representation of the line MIL-S-8802 sealant around it (thin black stripe).  This was done with an Eduard rice paper masking set for that kit.  It included 2 sets of masks for the main canopy section that were just slightly different in size, so the masked areas were offset just a little to leave the simulated sealant stripe.

A representation of the sensor section mating collar on an AGM-65D in 1/72 scale (thin silver stripe with a bunch of glare from my camera flash coming off of it).  This was just careful placement of two strips of Tamiya vinyl tape, covering the rest of it with Tamiya rice paper masking sheet material, and airbrushing a tiny bit of Testors square bottle metallic silver paint.

Good masking is important, but putting the paint on nice and thin is the key that makes it all come together at the end.

Master Blaster

shoot a layer of future???

 

                          

Eaglecash867

Lots of other good stripping methods out there, but DO NOT use oven cleaner (still popular for some inexplicable reason).  The chemicals in oven cleaner will react with the styrene, alter its molecular structure, and you'll end up with a piece of plastic that is now much more brittle than it was before.

Depends on the age of plastic. I've used Easy Off to strip paint with no issues of styrene getting brittle on me. I usually let it soak overnight in a covered tub, then rinse/scrub with a toothbrush with cold water.

True there are other methods...

Brake fluid - which I think is the worse method because brake fluid can crazeor soften plastic.

Simple Green - Non-toxic, no harmful fumes but takes too long. Some folks swear by it, others say it sucks. 

Testors Easy Lift-Off Paint and Decal Remover - effective but expensive. Comes in a 8oz. bottle. Runs around $20 or so.

Finally, the next method I have never tried but folks say it works...

Super Clean, aka: Castrol Super Clean - The "Purple stuff" Simply immerse part in a bucket/tub for a couple hours, remove and rinse/scrub with a toothbrush. WEAR GLOVES!!!

I usually wipe again with Isopropyl Alcohol after any paint stripping session.

DooeyPyle67

Depends on the age of plastic. I've used Easy Off to strip paint with no issues of styrene getting brittle on me. I usually let it soak overnight in a covered tub, then rinse/scrub with a toothbrush with cold water.

Stripping with Isopropyl Alcohol takes about 20 minutes from start to finish.  

Rather than future, I seal the edges of the tape with a coat of the underlying color.  That seals the edges of the tape so that paint cannot wick under the tape.  I have also used a clearcoat instead of future, but I believe sealing with the underlying color looks slightly better.

Thats my method as well.

rocketman2000

Rather than future, I seal the edges of the tape with a coat of the underlying color.  That seals the edges of the tape so that paint cannot wick under the tape. 

 

                     

             Never thought of that!

First thanks for everyone’s time and advice on this. After reading all the responses I got I decided to set aside some time this morning to experiment with everyone’s input.

The link at the bottom shows pictures of my results this morning. I decided to use plastic spoons to test all this with, as we have several hundred left over from a wedding. Guess no one felt like spooning! :)

The first pic shows all 10 spoons, 6 I applied the U.S. airbrush color to and 4 I applied Revell.

The first 3 spoons I applied the paint as it was out of the squeeze bottle. The bottles say air brush ready, and it did seem to cover okay as is. The next two spoons I mixed the paint with the reducer (Larger bottle) 1 to 1. As u can see they streaked and kind of did that freckled thing paint does. It seemed way to thin for the brush. The last of the 6 spoons painted with U.S. Air brush with just a few drops of the white it did seem to lay down a little better. {Course by then I had painted 6 spoons so maybe that was part of the difference.}

Finally, the last 4 spoons I first painted with a grey primer, let them dry overnight and then did some simple taping. On top of the primer, I painted the Revell Aqua color mixed with the white bottle again 1 to 1 as the Revell paint in that square container is very thick.  I felt that the Revell painted easiest and other then the tape taking up some primer of one spoon the lines were nice and sharp.

So that’s a lot to see. Take away for me was that getting any paint to the right consistency is a challenge. I saw someone using some cheap eye droppers to get paint from bottles and then equal parts extender of some kind. So I bought some of those and mine suck up paint great they just don't want to give it back to you.

Also did drop the pressure to under 20psi from the 35 I was using that helped I think to.

https://photos.app.goo.gl/1XjVdKTJyRVuSzmu9