Paint/build questions

[Tyson]

For you guys that use an airbrush, I have a few questions.

I started priming tonight. First time I've ever used an airbrush. I'm using a double-action, internal mixing suction fed with a compressed air canister, since I can't spare the money for a compressor at the moment. I do plan to get one soon, however.

I set out to prime the main chassis bits. Using water based, acrylic white primer. The first half of the chassis went smoothly, and I was pretty proud of myself. Then the second half was a bit iffy, and each subsequent piece became worse and worse. I was getting plenty of air pressure, but the paint started becoming lighter and lighter. Thought it might be a clog, so I took everything apart and cleaned it out. Subsequent pieces were a bit "wet." Is there anything I'm doing wrong?

Also, anyone care to elaborate on their step by step process of building and painting. Any and as much info as anyone is willing to give would be greatly appreciated.

[rnagle]

With the double action brush you're controlling both air and paint with same finger, it may be possible your "trigger finger" was getting a bit tired causing the ratio of air/paint to change. There may also have been some blockage where paint enters pickup tube from the bottle itself.

As for the step by step process, I tend to build as much of the chassis as possible and paint the whole works. It can be tricky getting into various tight areas however the control of paint delivery possible with an airbrush gives good results and doesn't produce excessive paint buildup.

Same goes for cab/hood, as much assembly as possible before painting. Any items that are a contrasting colour I prefer to paint separately and attach later. For some small pieces like horns or door handles it can be helpful to drill and add a small wire "pin" to the connection rather than relying on glue itself.

[muleskinner]

I find that the propellant cans will start to get condensation on the outside and dampness will start to form in the inside of the can as well after prolonged use and not giving the propellant time to rest. As a result the propellant will start to pick up moisture in the can and force it through the tube with the propellant. When it reaches the paint siphon or nozzle which ever type gun you are using and the water will begin to thin out the mix as it exits the gun.

Propellant cans also have another downfall which people don't realize. They are filled on an assembly line and as they get towards the end of the line, some cans will receive less propellant then others and as a result they loose their potency in use because of it. I have run into this more than once when I was using the can method.

Another thing which you might want to do is check the nozzle of the gun periodically for paint globs which can form at the tip out let, from impurities in the paint. If they happen a lot it is best to look on a site such as Micro Mark or one of the others for an in jar tube filter which keeps major unmixed globs in the paint from being drawn up into the nozzle area.

One more thing to try is buying some Acrylic Paint Thinner which is made for thinning acrylic paint for use in the Air brush mixture. Water from the tap has some times, depending how they process it, chemicals in it which has a slow coagulating effect on the properties of acrylic paint and tends to cause the paint to glob up in the mixture jar. Water will also cause acrylic the dry faster in some cases depending on the type of acrylic you are using.

William

[Tyson]

Thanks fellas. I completely dumped the propellant can. Took the dive and bought a nice air compressor. Everything's going as smooth as silk now.

How do you guys go about sealing your builds, and what particular sealer do you use?

[Deleted]

Sept 1, 2011 6:09:09 GMT -5 Tyson said:

Thanks fellas. I completely dumped the propellant can. Took the dive and bought a nice air compressor. Everything's going as smooth as silk now.

How do you guys go about sealing your builds, and what particular sealer do you use?

When I seal or clear my paint jobs it is just usually clear acrylic from a spray can that is applied before windows are installed. Or I may airbrush Future floor polish over the whole model.

[rnagle]

I've been using Testor's Glosscote & Dullcote in spray cans for clear finish (Glosscote prior to decalling, Dullcote for final "flat" finish) with good results

[Tyson]

Do you guys work in layers? Can I go over enamel with clear acrylic, decal/detail/weather and then seal it with a dullcote enamel? I have some Mig pigments I want to use to dirty trucks up a bit.

[muleskinner]

Sept 6, 2011 9:15:06 GMT -5 Tyson said:

Do you guys work in layers? Can I go over enamel with clear acrylic, decal/detail/weather and then seal it with a dullcote enamel? I have some Mig pigments I want to use to dirty trucks up a bit.

My best sugestion to you is do not use clear acrylic over enamel, because acrylic and enamel have a tendency to not coopertae with each other chemicle wise and property wise. In a lot of cases, acrylic will/might turn yellow or even crack and begin to raise from the enamel after a period of time. Unless you are looking for that weathered look on a model I wouldn't recomend it. If I paint a model with enamel and because I weather all of mine, I use the acrylic earth tones over the enamel whilen it is still tacky and let the acrylic dry along with the enamel. The earth tone acrylic will begin to crack and seperate on the enamel and leave a dried on cracked mud texture.

A lot of guys spray on a coat of future floor wax as an over coat, I have tried this and have had the models start to turn a yellow color and also crack. I woukld recomend using Dull Coat or Gloss coat on your enamel as and over coating. It can also be used on acrylic after the acrylic has dried completely and cured for as few days.

If you are painting with and airbrush I would recomend layering the paint in light coats and letting each coat dry thourouhly between coatings. When using the Dull coat or the Gloss coat I recomend the same technique so as not to get any runs in the coatings over the paint. The last thing you want is a beautiful paint job ruined by the Fixturee coating showing runs. A slow and patient paint job is better than a hurried through job which will show in the end.

William

[Tyson]

Due to the local hobby shop having a very limited selection I had to settle for acrylics and Revell enamels. I primed and painted most of the body of the truck with acrylic, and I've used enamels for detailing.

So, from what I understand, I can gloss coat with the Revell clear gloss finish, decal and Revell clear matte finish.

Can I then weather with Mig pigments? Anyone have any experience with this? It says to use the pigment fixer or thinner for washes. Will any of this negatively effect the clear enamel? If not, after I weather should I then go over everything again with another matte finish?

[muleskinner]

Tyson,

If you go to the section In The Shop on this forum and pull up my thread; Update: Lidgerwood Tower Skidder in Progress, I did a short critique on how I do acrylic washes when weathering my builds, on the third [page of that posting. It might help you in finding your answer.

This is my technique for weathering which I have used for about forty years I've been modeling.

William