First time using an airbrush, and I have a few questions?

i had some of your problems the first time i used an airbrush..

QUOTE: I guess my main question is why is the consistency of my paint changing as I am painting?

first make sure you mix your paint properly. i do it for a minute or so. second make sure you have the right paint to thinner ratio. try 2 parts paint to 1 part thinner. other people do it at 3:1. i mix in a seperate container and not in the jar the paint came in.

for the second question.. when faced with a large suface area, remember to Start the spray with a sweeping motion Off the object and Stop the spray Off the object. i dont do it in sections because i will have to start my spray in the mid part and i might get some "pooling". be patient and start with thin coats, then go from there a lot of thin coats is better than a few thick coats. when faced with a dilemma when spraying horizontally..,why not try vertically?

Hope this helps, try the ABC's of airbrushing found at the top of the Paint and Airbrushing Forum that really helped me a lot when i was starting out.. Happy modeling!

QUOTE: I had the tendency of going back and forth while I was spraying the inside of my 3-foot hull on my UBoat

3-foot hull?!?!?! wow!

anyways, everything Luis said about spraying a large area is right on. keep the AB moving, start and finish off the model, and apply several thin coats. sorry, can't help you with the paint mixture as I use acrylics, but trial and error with thinners is the best way to learn.

First thing I would do is buy some Model Master airbrush thinner and see how it does. You may have a weird reaction problem with different manufacturers products.
You could also buy some high-quality mineral spirits from the hardware store and try that as they are about the same thing as the MM airbrush thinner.
Try mixing the paint to thinner ratio at about 2:1 and see how it does.
Mix it well in another container and then pour it through a piece of pantyhose material into the airbrush cup to strain out any paint clumps that could be in there.
Then try spraying it at around 15 psi from about 3" away and see how it works.

Mike

Thanks alot for the posts. After thinking about it for awhile, and talking to my wife, I think the problem with my paint flow not being consistent was related to me not mixing my paint and thinner well enough. I just put the paint into a 35mm film case, and then added the thinner, and then just dumped the mixture into my airbrush. I guess I thought the thinner would just automatically mix with the paint. I am almost sure that mixing better will solve my inconsistent paint flow problem.

Another problem that I had was not having adequate equipment for measuring out my paint and thinner with, and then putting into my 35mm camera case. I just dumped the paint and thinner into an old teaspoon measuring tool, and then dumped it into the 35mm film case. My mixture ratio was not accurate at all, and it was a mess dumping from the paint and thinner bottle into the teaspoon, and then dumping that into the film case. I am buying some eye droppers, or syringes, today for sucking paint and thinner up with so I can be more accurate and cleaner.

I also see your point of spraying vertically. I have no idea why I didn't think of that. I guess I have to learn to think in three deminsions. Ha!!!Ha!!!!

When keeping your airbrush moving over the model, like you suggest, do you keep it moving in the same direction from one end of the model to the other? Or, do you constantly keep the airbrush moving, but sometimes you will change directions and go back over an area you missed or add a thicker layer of paint on an area you just covered?

Graduated pipettes are useful for measuring paint. They are available in glass and plastic, but aren't easy to find. You can also use regular pipettes or straws to measure the paint in a plastic measuring cup, or a nice glass one that is like a shot glass.

Make sure to mix your paint thoroughly before painting. Enamels spray great which is why you were able to spray at first. The paint clumping could be the same problem, or it could be too much time between projects and there was dried paint on the needle or tip. Just run a quick shot of thinner through it before you let the AB sit for awhile.

In my own personal experience, Iwata's aren't that great for using enamels. But that is probably just me.

QUOTE: When keeping your airbrush moving over the model, like you suggest, do you keep it moving in the same direction from one end of the model to the other?

Yes, after one spray line,stop,then start agen moving one level downward slightly grazing the fist line you made..left to right (i am right handed).

QUOTE: do you constantly keep the airbrush moving, but sometimes you will change directions and go back over an area you missed or add a thicker layer of paint on an area you just covered?

Practice,practice.. keep on practicing spraying even lines. but in the event you miss a spot,(assuming it's not a huge spot ) don't be tempted to go over it again because yout paint might pool.that's bad.. what you want to do is to continue finishing the first coat of the object being painted. then after about a minute, during your second coat, go over the missed spot.(again assuming it's not a big spot) it will all even out in your 3rd maybe 4th coat.

The first coat should be light. spray about 5-6" away from the object. the next coats can be sprayed a bit thicker and nearer. maybe 3-4".

Just visit the ABC's of airbrushing. it's all there Hope you do well on your U-Boat. Show us pic's when it's done ok? Happy Modeling bro!

I will try this later today I hope. Thanks for the advice. I do have two more questions. I will be using an Iwata HP-CS brush with White Ensign Models Colourcoat enamel paint mixed with paint thinner (or Model Master enamels mixed with Model Master's paint thinner).

1) What size line of paint should I try to get when painting a rather large surface (such as the hull of this 3 foot U-Boat)? How is the best way to get this size spray line with my mentioned equipment? I guess I will be wanting to get a rather large spray coverage area for each spray line that I do. If I end up spraying with small 1/2 inch to 1 inch lines I am visualizing an uneven paint job that looks scribbled on, or a paint job that shows dark lines going side to side on my hull that are darker because they recieved a direct spray from the airbrush compared to surrounding areas that did not recieve a direct spray line. I guess it would be nice to be able to totally cover my 3 1/2 inch wide hull area with 2 or maybe 3 seperate spray lines.

2) When painting this large area, how far back should I be pulling my action on the brush in order to accomplish the answer to my first question? Will I get bigger and better spray coverage areas by pulling back further on the action (perhaps even pulling it all the way back), or should I just pull it back half-way and then adjust by putting on extra coats? I know this action is controlling how much paint you are spraying through the brush. I just want to know how much paint flow is best to cover large coverage areas. I am thinking the less I pull the action back (the less paint I let through the brush) the smaller my spray area is going to be. However, the more I pull the action back, I am starting to lose the ability to apply a fine light coat of paint that does not hide details on the model.

Beleive it or not, I am not too concerned about painting the finer details, or smaller parts, on the U-Boat like I am about painting the very large hull surfaces. I doubt I have many problems painting the smaller parts. I don't even think the conning tower will be very difficult to paint. My next subjects are going to be 1:350 scale battleships, so I better get used to painting these large surface areas.

QUOTE: 1) What size line of paint should I try to get when painting a rather large surface (such as the hull of this 3 foot U-Boat)? How is the best way to get this size spray line with my mentioned equipment? I guess I will be wanting to get a rather large spray coverage area for each spray line that I do.

Yes use the largest nozzle that you have. no sense using a small tip for a large hull

QUOTE: If I end up spraying with small 1/2 inch to 1 inch lines I am visualizing an uneven paint job that looks scribbled on, or a paint job that shows dark lines going side to side on my hull that are darker because they recieved a direct spray from the airbrush compared to surrounding areas that did not recieve a direct spray line. I guess it would be nice to be able to totally cover my 3 1/2 inch wide hull area with 2 or maybe 3 seperate spray lines.

If there is one thing i've learned, is that experience is the best teacher. Practice spraying on Extra styrene pieces that you have lying around.don't test on paper or cardboard as it is pourus and will just absorb the paint. find a large peice of had plastic close to the likeness of styrene. i use hard plastic "Trays". (yes the one people use for serving food) it fits me perfectly for paint i like to test.

QUOTE: 2) When painting this large area, how far back should I be pulling my action on the brush in order to accomplish the answer to my first question? Will I get bigger and better spray coverage areas by pulling back further on the action (perhaps even pulling it all the way back), or should I just pull it back half-way and then adjust by putting on extra coats? I know this action is controlling how much paint you are spraying through the brush. I just want to know how much paint flow is best to cover large coverage areas. I am thinking the less I pull the action back (the less paint I let through the brush) the smaller my spray area is going to be. However, the more I pull the action back, I am starting to lose the ability to apply a fine light coat of paint that does not hide details on the model.

even if you pull the trigger all the way back, it's still your sweeping movement that counts. dont go too slow,and dont go too fast either. just practice first, believe me,it helps. Keep the faith and you'll get there

Here's where I get my pipettes.

http://www.pelletlab.com/lab_supplies_pipettes.htm

QUOTE: Originally posted by ryanpm In my own personal experience, Iwata's aren't that great for using enamels. But that is probably just me.

I personally find Iwatas great for spraying anything. My Iwata works wonderfully for spraying enamesl and acylics. Haven't heard any complaints from people that iwatas don't spray enamels well.

Most if not all airbrushes will spray acrylics and enamels well. My hp-bcs (same as your hp-cs but siphon feed instead) sprays both enamels and acrylics beautifully. Your problem was most likely your thinner paint mix as has been said. Good luck with your poject!

Well, I finished my first task with the airbrush. After all my worrying, I must say that there wasn't much too it at all. I painted the upper half of the two hulls with Hellgrau 50. I also painted the conning tower pieces, and everything else that gets painted with the same Hellgrau 50 paint. I feel that I got very smooth coverage, no running, no scribbling, and several nice coats on the main hull section (I put about 4 light coats on it).

Is it true that adding more coats of paint will actually make the color being used be a darker shade, or does adding more coats only assure yourself of full coverage while not effecting the overall shade of the color being used? How many coats should I have put onto the hulls? Even after putting on 4 coats at 15psi, there was still only a light coating of paint on the hull.

i don't think repeated coats of paint will darken the shade of the paint being used. Remember that paint thins while drying.. thats why we let coats "Dry" before applying next coats..if you dont let it dry properly, you will get pooling.

QUOTE: Even after putting on 4 coats at 15psi, there was still only a light coating of paint on the hull.

this might be because of your paint mixture. paint seen on the bottle does not necessarily mean paint seen when sprayed. the paint that you mixed might be too light for your taste. 4 coats should be more than enuf to cover that area..

QUOTE: Another problem that I had was not having adequate equipment for measuring out my paint and thinner with, and then putting into my 35mm camera case

Thinning ratios do not have to be accurate, there is no "Magic Number". As long as the paint sprays at a particular pressure that is all that matters. The only reason for thinning paint is so that it will spray at a particular pressure. If it sprays right from the bottle, that's fine. If you have to thin it 1:1 (and can still get it to cover properly) that's fine to.

If you were just dumping the paint and thinner together without thoroughly blending them that is your problem. You were spraying just thinner, then thick paint, then blended paint, then just thinner .......