Hi - I'm doing my first spray with the Iwata using lifecolor paints and thinner. PSIn is set to 10 PSI & I'm using roughly 50/40 thinner to paint ratio.

The paint in some places goes on well, however, in others the paint lands in "bubbles" - it does not adhere to the pastic very well and pools together in many smallish bubbles.

I have cleaned the plastic before construction, then after construction sprayed liberally with Windex. Perhaps I should have scrubbed with windex rather than just spray?

What am I doing wring here? Too much paint, too thin paint, plastic not cleaned well enough?

What is the average ratio of paint to thinner that I should be using??

Thanks.....IAIN

Iain,

This has me stumped.
The model I'm finishing now, I just shot Lifecolor paint thinned 50/50 thru an Iwata at 15 PSI. It worked flawlessly.
Spraying with Windex and rinsing with water is sufficient to clean the model - you don't have to scrub it.
Did you handle the model with bare hands after you cleaned it? It sounds like there is oil on the model making the paint bead.

Hi Matt




I did not rinse with water - only sprayed with windex and let it dry........This probably explains why the paint (in some areas) goes all bubble-like and does not adhere well to the plastic. The paint layer I was applying was only a rust coloured primer to act as a base coat for weathering - so not a major issue.

I'll try the 50/50 ratio at 10-15 PSI and see how the painting goes. It's possible that I was was not diluting my colour well enought with the Lifecolor dilution mix (in the lifecolor bottle). When I cleaned the airbrush, the needle section at the front of the brush required some cleaning as the paint had gathered around the needle exit hole.

Thanks Matt...........Iain

You're welcome Iain!
I prep my model at the kitchen sink. I spray it down liberally with Windex, soaking it. Then when I'm convinced it's all squeaky clean, I rinse it with cool water with a gentle spray from the sink sprayer hose. Then I place it under a Tupperware, with some spacers to let air in, and let it dry overnight. If there's no good spot to hold the model, I wear surgical gloves to keep skin oil off.
You shouldn't have a problem with the paint and airbrush.
Let me know how you do.

Do you pre paint it before the real coat? Maybe that would help Bob

Hi Matt & Bob

Bob - no I did not apply a proper primer coat.

I sprayed the constructed model with windex and allowed to dry for a week (note I didn't wash the windex off, which I should have done). I then spayed a base coat of lifecolour red primer, followed by another coat of tamiya olive.

Matt - I tried your combination of 50/50 using tamiya and tamiya acyclic thinner. The paint sprayed 100% better. I think my problem earlier was that I had not diluted the lifecolour paint to the consistency of "skim" milk!

Now another problem has arisen which I believe is a result of not washing the windex from the model before painting. The 2 thinly sprayed coast of paint peel very easily when you scratch the plastic with - say your fingernail. The paint only scratches off and does not rub off!

Is there a post painting process to solve this?

Finally, is it better to apply 3-4 very thin coats of spray paint as opposed to 1-2 more thickly applied coats??

This is my first proper model for many years, and my first use of an airbrush, so I'm not too worried. This KV2 is a tester for "tnew" skills.

Cheers................Iain

I've had the same experience with Lifecolor but not as drastic.
Now I always prime my kits with Tamiya primer and the coats are very smooth.
I guess that the plastic has some release agent from the molding process and Lifecolor paints do that.
Tamiya colors seem to be immune, and with Vallejo can also happen but the bubbles are almost invisible. But with a magnifying glass you can see the tiny bubbles.
The only solution is to sand it and do another coat. In fact these bubbles mean that the paint did not adhere to the surface.
To avoid it do a primer coat with either Tamiya acrylic paint or with the spray primer from them. Excellent results all the time

When you say the Tamiya paint scratches off easily.... How long have you left it to cure? Tamiya paint "touch drys" very quickly, but can take a day or two to fully cure. When dry but not cured (eg. first 4 hours or so) it can be scratched very easily - after this time it will begin to harden.

It is far better to apply multiple thin coats, regardless of which particular paint medium you're using. It's much easier to add more paint if required than it is to remove paint if you make a mistake.

Thanks

Phil: The paint scratched off after 24 hours. The paint bubbles in some locations as I didn't wash the windex from the model. It only happened in a few areas.

On my next model, I'll use Tamiya as a primer coat and then use the Lifecolour paints as addtional spray coats and see how that goes. This model is really a "training model" so mistakes are expected. Thanks.....IAIN

It sounds like the paint beads because of the windex, but if the answers you've seen here have not worked, I'd suggest priming the model.

I used Halfords (UK car accessories stockist) acrylic primer from a spray can and just give everything a coat.

I've had enamels and acrylics sprayed on top and it's worked fine. Some of my older models (before I used primer) can be scratched and the paint flakes off so I'm happy that the primer has done its job.

Worth a try I think

Stuart

Hey Matt

When you spray Lifecolor 50/50 what are you using as an additive to the paint - Lifecolor thinner, water, or Tamiya thinner??

Thanks Matt................Iain

Hi,

I recommend always priming your models when painting with acrylics. They just don't stick to bare plastic as well as enamels. While they will certainly adhere to a well cleaned surface, they don't do it very well. The resulting surface will be quite vulnerable to scratches and other damage. A coat of primer gives the paint something to grip onto.

From your description, paint going on well in some places but forming droplets in others, I'd say that you got some mould release of oils from your hands on your model's surface that's rejecting the paint.

Wiping the tip of the airbrush needle clean every now and then while working doesn't hurt if you see paint drying up to the needle tip.

Hope this is of help.

Iain I use distilled water with Lifecolor. Works like a charm.

Thanks Matt. Everything is coming together. It just took some time, practice and patience - all three which are often lacking.............Iain

Oldie but Goodie!
Building my 1st model in 30 yearsish. Was wondering if any prepping needed before primer. Sooo I googled how to prep model before primer. This thread was what I was looking for!!

At Iain
Thanks for the questioned about "not cleaned well enogh".

At Tom
Thanks for the answer about prepping model! That's some good information. Ive been reading more of your answers to other questions on this forum. There a lot of help!

Thanks
John

Prep is important. Clean the plastic, rinse well and let dry. Prime the surface, Tamiya's works well. A good primer adheres better to the plastic than paint alone. you can also see flaws that can be fixed before the color coat is applied.

91% isopropyl alcohol will lift the paint off and take it back to bare plastic.

Hi John

I wash all plastic in the sink with dish washing liquid. Only a mild amount. This removes any oil from the plastic. I then rinse well and dry. I stopped using windex as washing up liquid did the trick.

Prior to painting I spray a coat of primer. (I use an assortment of brands) but prefer other brands to life colour for the primer (just my opinion based on my experience)

Seems to work well for me. Cheers. Iain

Hi Iain

How do you apply the liquid soap? With a spray bottle (soapy water), apply little on fingers then rub or.... I would like to give it a try.

Thanks
John

I prep my models the same way. The only thing needed is dish soap, water, and a soft, large brush (i use a worn cheap 1/4 inch brush from a hardware stuff. Its important that the brush be very soft so you dont damage the fragile bits of your model.

I run the model under some water than lather up the brush with dish soap. I gently scrub the model with the soapy wet brush, then rinse and let air dry. Sometimes, you can get water spots on the smooth plastic. These can be removed with some rubbing alcohol on a paper towel. If you are getting lots of spots, rinse the model in distilled water after you lather it.

I always recomend using a primer when using acrylic paints (tamiya paints are actually an acrylic lacquer and do not needa primer). I like to use Mr. SURFACER 1000 thinned with mr. Leveling thinner or the acrylic thinner from Ammo of Mig Jimenez.

The paint to thinner ratio and air pressure all depends on your airbrush setup and your climate. I have never had success with lifecolor paints. For tamiya paints, i usually use 1 part paint to one to two parts thinner (tamiya lacquer thinner for best results).i use about 23 psi through mu airbrushes that range from a .2-.5 mm nozzle.

Lately i have been using only Ammo of Mig Jimenez acrylic paints. These paints are the only paints i recomend airbrushing straight from the bottle (i add some acrylic retarder and if i need to thin the paint, i use tamiya acrylic thinner).

The key to successful airbrushing is to apply the paint in very thin layers over clean, degreased plastic or, better yet, a layer of primer. The paint should be shiny when it hits the surface and should produce a minimum of texture. Always try to spray away from corners; your airbrush should not be pointed in a 90 degree angle to the surface of your model, otherwise the mist of paint will dry to a rough gritty texture.

Cleaning your airbrush is not difficult and rather easy. Just pour some appropriate thinner into the cup, cover up the tip of the airbrush with your finger, and pull the triggr. Bubbles will come up through the color cup. Scrub everything with few q tips, remove the needle and clean it, then assemble. Done!

Airbrushing is very easy to do once you figure out what works. Keeps playing around and find what works with you!

Adam Wilder has a few great videos on airbrushing. You can find them at youtube.com/wilder.

Hi John

I wash the plastic as I would dishes except I use cold water. Iain

Excellent info Gents!!

Thanks
John