discussion Airbrush vs. Rattle Can

[Guest]

So I'm a little frustrated with airbrushing. I've painted some planes in the past but they typically had a flat or matte finish. Trying to paint some cars with the airbrush and I end up with bumpy coats. Doesn't look like orange peel. Looks like possibly the paint is drying before it hits the surface. Almost like dust on it, but very even over the whole surface. I've tried reducing the airpressure, and I'm below 10psi now.

I was thinking that I wasn't painting thick enough, but I got to the point where the paint was almost running off the model and I still get that finish. but with runs and pools! So what am I doing wrong?

Working with Tamiya and thinning it 1:1 with Tamiya thinner. Should I thin it out more? Use water or something else instead to retard the drying of the paint?

I honestly can get nice paint jobs with a rattle can. Almost glass smooth! But the airbrush is just defeating me!

Anyways this Mustang is "done". Waiting for some micromesh to arrive on monday and I'll just try and buff it a bit smoother and live with the results....

 

[BarryW]

Andrew. Try using Vallejo Model Air. It is formulated for the airbrush. Humidity and temperature are a factor though.

Try spraying at about 20 psi building up thin coats. Two things to try if you still get a rough finish. Thin Vallejo with about 10% Vallejo airbrush thinner that includes a retarder. Or put a drop of retarder in the paint, just a drop.

 

[Ian M]

I also avoid cars for the same reason. The finish. On a tank that is going to get weathered and plastered with mud and dust not to much of an issue if the finish is not perfect. (but not an excuse to be sloppy).

I have a plan you might like to try out. Spray an object with a rattle can, and really think over what you are doing; how far away from the subject you spray, how much paint you lay down each pass, then preferably in the same session, repeat with the air brush and give it the same thoughts.

It might be the pressure, it might be the paint its self. I have no idea at which pressure spray cans work but maybe you could find out.

Also have you tried to spray the paint from a rattle can through your airbrush?

As far as airbrushing a good gloss finish I have had much better luck with Humbrol enamel paints than with any acrylics. Build it slowly in light coats and it come out OK.

As for the dusty finish, you are to far from the subject and the paint is drying in the air.

Ian M

 

[PaulTRose]

for airbrushing these days i have completly turned to vallejo air............makes like so much easier

for cars and bikes tho, i almost never use the airbrush, always rattlecans......one trick is to sit the can in hot (not boiling!) water to up and equalise the pressure........and give it a bloody good shake first! lol

i am about to start experimenting air brushing nail varnish for use on custom car models

 

[Ian M]

...

i am about to start experimenting air brushing nail varnish for use on custom car models

Good luck with that. I have not had much success with it. I would be pleases to see how you get it to work.

Ian M

 

[stona]

How often do all you acrylic users have to stop and clean the airbrush nozzle due to paint drying in the paint way or in the nozzle or somewhere else it's not supposed to?

Just asking, be honest. I never, and I do mean never, have to do it, but then I don't spray acrylics

Cheers

Steve

 

[Guest]

Actually Steve this depends on a number of factors.

Colour as some acrylics colours are easier than others.

Temperature better down below lounge temperature.

Needle nozzle size. .4 very little problem

.2 needle nozzle not good.

Forget to add thinners to Vallejo Model Air recipe for problems..

Usually I can clear a blockage by wiping in the front end in the needle area with a cotton bud laden with thinners & pulling the trigger back & forwards. Also increasing pressure to clear if necessary.

Very unusal to have to strip down during airbrushing.

The answer yes some problems but minimal which get less with experience of use of acrylics. Also staying with the same manufacturer you get to know the potential problems.

All worth the above as drying is a lot less time consuming than enamels & I am impatient. Second coats can be applied as soon as the coat looks dry & with safety within 2 hours.

Not sure of the difference between acrylics enamels etc but having flirted with enamels in the very beginning I am prepared to take a slightly lower result,if that is the case for work on mostly ww11 aircraft, for the ease of use of acrylics.

Very interesting subject. Be interested to hear more views.

Laurie

 

[PaulTRose]

i strip and clean my ab as soon as i finish spraying

ive had lots of cheapo ab's that have always ended up giving me problems

not long ago i invested in a iwata so now im kind of obsessed with keeping it clean, cant afford another for a long time.......to be honest it isnt much of a job,...strip, cleaned, put away in about 5 minutes flat

 

[Guest]

one trick is to sit the can in hot (not boiling!) water to up and equalise the pressure........and give it a bloody good shake first! lol

Yeah that's exactly what I do with rattle cans. Hot water, and shake shake shake shake! and shake it some more even after you think it's done! Light light light coats, letting them slightly dry to give the heavier coats something to bite into. Comes out smooth like glass! I try to spray similarily with the airbrush and acrylic. Maybe I'm going too heavy on the later coats...

I think maybe I'll buy some styrene sheets and try and get a technique built up!

In the meantime the next couple of cars are getting the rattle can treatment until I get this figured out! Airbrush will be for smaller parts and airplane kits for now.

 

[Guest]

How often do all you acrylic users have to stop and clean the airbrush nozzle due to paint drying in the paint way or in the nozzle or somewhere else it's not supposed to?Just asking, be honest. I never, and I do mean never, have to do it, but then I don't spray acrylics

Cheers

Steve

I never have problems with that. But I give the airbrush a good cleaning with glass cleaner after painting for an afternoon. I strip it down and clean it every couple of painting sessions, and make sure to give the needle a good coat of needle juice. That seems to help with having it get sticky as paint dries inside the brush.

 

[Guest]

Or put a drop of retarder in the paint, just a drop.

As for the dusty finish, you are to far from the subject and the paint is drying in the air.

I think it's a combination of these things. With the lighter coats I should likely be in closer. I think the paint is flashing off before it has a chance to self level. I had this problem with the semi-gloss black as well. It was turning out more like flat black. Reduced pressure, sprayed closer and I got a much better finish. I have to figure out what exact adjustments are needed for the gloss black....

BTW what can be used for a retarder for tamiya acrylic? I figure distilled water instead of their thinner would likely make it take longer to flash off.

 

[Wendall]

Andrew, I believe that the tamiya thinner is formulated with a retarder so you shouldn't need to add any. I generally thin tamiya acrylics if I am brushing or air brushing normally 1:1 for the ab and a drop or two otherwise. Regards painting the body I always use tamiya spray cans. I've not been able to get the same result with the ab and I have painted cars professionally for 12 years... I now use the ab for mainly detail painting. For parts that require a flat black or semi gloss finish I stock up on spray cans at my local motor factor, it's much cheaper that the tamiya equivalent and IMHO just as good.

Keep at it matey

Jason

 

[stona]

Yes, I'm not trying to start a row, you know, enamel v acrylic, but it is an interesting topic if everyone can put their view, and no one gets overheated

Here is my personal experience.

In my case I did change to acrylics a few years ago (actually shortly after I joined this forum I think). After a bit of experimentation I got on with them okay and got some satisfactory results using mainly Vallejo and Xtracrylix. Despite adding a retarder and sometimes a flow aid I rarely managed an entire trouble free session of spraying. I found I had to clean my airbrush thoroughly after every session, even between colours. Acrylic paints do dry quickly, and that includes in your airbrush!

I reverted to enamels after a couple of years and have never gone back. I use a mixture of Humbrol and White Ensign Colourcoats. The former are a bit inconsistent as regards colour and quality but usually spray alright. The latter are superb, the Colourcoats are the best paints of any type I have ever sprayed.

I never have blockages or problems spraying. Enamels are much more sympathetic to "approximate" thinning. I never measure anything, I just thin until the paint looks right. I can flush my brush with a couple of half cups of white spirits between colours. I can give it a quick clean at the end of the day (including removing the needle and back flushing before re-assembly) and it will be fine for the next day. The last time I really stripped and cleaned my Iwata CS was after about three models. I have another Iwata (a BR) which I use for detail painting as it is smaller and has a much smaller paint cup. I'm sorry to say I can't remember when I last broke it right down. It sprays beautifully and I've had it for many years. I have only ever replaced the needle and nozzle (once) both due to my own ineptitude!

I can sum up my opinion (that's all it is, not right or wrong) in two sentences.

The only advantage of acrylic type paints is that they dry fast. The main disadvantage of acrylic type paints is that they dry fast

Much is made of the smell of enamel paints and their thinners. This will be a major consideration if you are working indoors or without proper extraction, I know because I was that person. I

consider myself fortunate to have somewhere to work with proper extraction. I know that not everyone is so lucky.This is probably the main disadvantage of enamel paints. I don't mind the longer drying time. Trying to rush a model at any stage, not just painting, is a recipe for disaster anyway.

Finally, just because you can't smell something doesn't mean it's not there. You should wear a mask whatever you are spraying.

Cheers

Steve

 

[Wendall]

"Finally, just because you can't smell something doesn't mean it's not there. You should wear a mask whatever you are spraying.

Good point Steve, some nasty stuff in all of these paints!

Jason

 

[Guest]

Yes, I'm not trying to start a row, you know, enamel v acrylic, but it is an interesting topic if everyone can put their view, and no one gets overheated Here is my personal experience.

(TRIM....)

I can sum up my opinion (that's all it is, not right or wrong) in two sentences.

The only advantage of acrylic type paints is that they dry fast. The main disadvantage of acrylic type paints is that they dry fast

Much is made of the smell of enamel paints and their thinners. This will be a major consideration if you are working indoors or without proper extraction

(TRIM....)

Finally, just because you can't smell something doesn't mean it's not there. You should wear a mask whatever you are spraying.

I could definitely see how that topic of enamel vs acrylic would get heated! Definitely depends on what you're modelling as well. So it's not a simple topic, and probably turns into a holy war.

I personally like the fact that the acrylics dry fast. with Aircraft it's definitely nice to work that way. With cars I'm better at planning and can paint one day and then assemble after. Again that comes down to my experience. I've build a lot of cars over the years but only a few planes. So I can plan ahead better.

Back when I used to paint with a brush I used enamels. But since getting back into things I definitely like working with acrylics because of the drying time. I have never airbrushed with enamels so my experience with airbrushing has been limited to acrylics, and Alclad II Lacquer. I do find that I can gum up my airbrush worse with the Alcad paints. But that comes down to work flow an experience. I used to have some issues with drying paint with acrylics and once I figured out that ammonia based glass cleaner cuts it like nothing I've had no problems keeping the brush clean. With Alcad I finally broke down and got some of their airbrush cleaner to try out, and cheep lacquer as well. My next couple of runs painting with it went a lot better with the proper solvents to clean it.

I'm wanting to get back to enamels but I do need a setup that can extract the air. I do paint with a mask (most of the time.... I know I know...). But the issue becomes smell in the house with the harsher solvents. I painted a couple of bodies with spray cans in the basement. We went out shopping after and came back about two hours later and the whole house reeked like solvents! I was not a popular guy with the girlfriend! Anyways, windows open and a few min later and the problem was solved. The next few paint jobs were done with a box fan in the window in my basement. Definitely helped. But I can't get away with doing that in the winter in Canada. I have plans to build a desktop paint booth with a 180 CFM range hood and duct it out the window in the spare room that I paint in. Hopefully that'll solve the solvent smell issue. Anyways long story short is that I'm basically stuck airbrushing acrylics until I get the paint booth set up!

 

[Guest]

"Finally, just because you can't smell something doesn't mean it's not there. You should wear a mask whatever you are spraying.Good point Steve, some nasty stuff in all of these paints!

Jason

And the fillers... and the glues....

Do you guys wear masks while doing that as well? Or only while airbrushing because of it being so finely atomized?

 

[Guest]

Some of the things I have found with my experience. These are based on Vallejo Model Air..

Use a two stage airbrush.

I always use Vallejo thinners. Not water. The thinners are designed to retard & also lubricate.

I always thin. Place the thinners in the bowl first. The small amount left at the needle end after mixing the paint & thinners will keep the needle nozzle free before use.

Make sure the paint is well mixed to give good consistency.

Found that using .4 needle/nozzle works best (I use Harder & Steinbeck brush).

Give a good full trigger back squirt on a plastic bottle before painting the real thing.

Where there is a lull dip the brush in a spot of thinners or resting the nozzle in thinner. Dry the nozzle before reuse & give a good squirt as above.

Found 18 to 20psi works well with the H & S.

Temperature below usual room temp.

Replace the cap on the paint immediately to avoid drying out.

Thin approx 20/25 percent.

Keep a cap on the cup during a session & after cleaning to avoid small hairs contaminating & to avoid premature drying out.

Use a small cup when ever possible there is less area for the paint to dry out.

Clean brush after every session. 4mins but saves many more.

Being basically water based rather than a slower drying turps sub acrylics are going to be more problematic. Although there is no guarantee with the above they will ensure, in my case, the very minimal of problems. A Bit of a pain ? Yes but all worth it to get the finish you want.

Laurie

 

[stona]

And the fillers... and the glues....Do you guys wear masks while doing that as well? Or only while airbrushing because of it being so finely atomized?

I don't wear a mask when filling and gluing. This is because I do have a well ventilated work space and my exposure is very low. I use thin cements which are very volatile. I keep the top on as much as possible, both to reduce my exposure and protect my bank account

The potential hazard with glues is vapour inhalation whereas with spraying paints an aerosol is created (along with the vapours) which can also be inhaled. I have a spray booth shifting more than 300l/min but still mask up for most spraying. I'll confess that if I'm doing a little touch up or very minor bit of painting I've been known not to put the mask on. I do always wear it when I embark on a job like applying camouflage, and for flushing the airbrush.

I'd hate this to turn into a this is better than that sort of thread. At the end of the day it is a personal preference which may well be based on factors such as where and how we work.

I did want to give a shout for the poor old enamels! I started spraying them when there really wasn't a choice, but now I find myself in a diminishing minority!

I find Alclads spray very well. My tip would be not to lower the pressure too much. They will spray at my usual enamel pressure of 30-35 psi and I can't be arsed to scrabble about adjusting my air pressure every time I change medium. I clean up with cellulose thinners (lacquer thinners across the pond) but this can trash some cheaper airbrushes.

Cheers

Steve

 

[stona]

That seems like sound advice Laurie.

I know that you are a Vallejo man but wonder if you or anyone else has tried Lifecolour paints. I've heard good things about them.

Cheers

Steve

 

[Guest]

Some of the things I have found with my experience...........Laurie

I am still a beginner and had a lot of trouble when starting airbrushing (Vallejo Model Air or Xtracrylix acrylics) in February: clogging, sputtering, uneven coating, especially with gloss varnish. I tried thinning (with the proper thinner) from 5% to 25%, altered pressure from 15 to 40 PSI, held the AB away from the model by between 2 inches to 10. For colour paint, I learned to do exactly what Laurie has described, including using a Harder and Steenbeck AB with 0.4 mm nozzle. For some time I have been able to reliably apply a good even colour coat at about 20 PSI with no problems. However, I am not sure what corrections I made. They just seemed to come, unconsciously. I now thin by eye, just "some thinners in the cup to milk consistency", which I was earlier on advised to do, which implies that the rate of thinning is not critical. I don't have drying at the tip but that might be because I don't normally spray for long periods, although I often brush the needle with thinner after about 10 minutes. I always thoroughly clean the AB after a session (but not between colour changes) and use an ultrasonic cleaner after every 3 sessions or so. Sputtering was cured by starting and stopping the stream off the model (although I do get the odd very small blob).

As for varnish, after difficulties, experiments and much practice, I can get a good hard glass-like surface after one spraycan wet coat of Tamiya Clear with the can about 10 inches from the model, as advised on the can. But I find that the ferocity of the spray can tends to cause pooling, especially at wing roots (where perhaps the jet is confined). Its a fine line between not getting a wet deposit and going too far.

I am now airbrushing Vallejo or Tamiya clear varnish with some success, thinned only 5%—it is so much more controllable than a spray can. I spray at 2 inches distance at about 20 PSI, further away produces no wet deposit (which seems necessary to get a gloss), only some dry powder, possibly due to the varnish drying before it reaches the model).

Its practice, practice, practice, on many ASDA or Sainsbury 2 litre lemonade bottles.