speckled eggs! Help!

[Guest]

Just painted the first coat onto my Tamiya Mosquito and seem unable to stop the spray gun 'spattering' like this image. I'm new to spray guns so advice very welcome. Thanks in advance. (Gun is a H&S evolution 0.2mm and tohe p[aint was Tamiya acrylic with about 20% Tamiya thinners well mixed in....the same paint by brush works well. Compressor set at about 20-25ft lbs).




speckled by John Dutfield, on Flickr

[Robert1968]

There might be too much air pressure coming through with the paint mixture causing the speckleing look. I normally spray around 15/ 20 psi when using a/b and at about and spray about 6/10 inches away from subject with sweeping actions top to bottom ( bit like a pendulum)


Hope this helps a little


There are better spray painters on here that will give you advice


Regards


Robert

[Guest]

Thanks Robert. I am quite new to spraying so certainly am open to all suggestions!

[Guest]

I've had this with Tamiya paints in the past.


Could be that the paint is drying before it's hit the surface or even drying on the tip of the airbrush if your using a 0.2 needle, did you find you had to keep unblocking the tip?


The paint should have the texture of skimmed milk, whereas if you dab some paint on the inside of the airbrush cup when your mixing it then it should go translucent quite quickly, I usually mix Tamiya paint 50/50 with Tamiya thinners with the air pressure around 15-20psi.


Atb,


Colin.

[Guest]

In deference to Robert, unless you're spraying at mega high pressures John, there's no way this would happen due to pressure. I routinely spray Tamiya at 30+ PSI without any problems.


The problem is caused by the paint drying before hitting the model surface as Colin said. Tamiya acrylics like to go down quite wet, so keep everything the same (pressure, thinning ratios etc), but just move the airbrush closer to the model.


That should solve the problem.


Cheers


Patrick

[stona]

I was just going to ask how far away from the model you were spraying? I'm thinking along the same lines as Patrick above.


Cheers


Steve

[Guest]

As Steve mentioned in the "what pressure" thread, you can't have too much practice, especially if you are new to airbrushing. Its the only way you'll become familiar with your paint / airbrush combo, and in an ideal scenatio, youll learn all the foibles attached to said combo! I'd suggest priming up a couple of 2 litre milk bottles, and keep a note pad handy to make salient notes. Itll pay dividends in bucket loads in the future, and you'll spot certain symptoms as soon as they happen.

[Robert1968]

In deference to Robert, unless you're spraying at mega high pressures John, there's no way this would happen due to pressure. I routinely spray Tamiya at 30+ PSI without any problems.
The problem is caused by the paint drying before hitting the model surface as Colin said. Tamiya acrylics like to go down quite wet, so keep everything the same (pressure, thinning ratios etc), but just move the airbrush closer to the model.


That should solve the problem.


Cheers


Patrick

I accept defeat there as I don't know 100% on A/b so I know when I find there is a problem with the paint the first cause of action for me was to turn the pressure down ( again to some paints this works ) but I have heard that higher pressures can work with paints but it depends on the type of paint. I've noticed tha as you say Tamiya likes it wet and seems to dry before getting onto the model hence I thin down more but then the density of the paint doesn't seem to go down evenly ( I know I'm still learning and learning )


Robert

[Guest]

I accept defeat there as I don't know 100% on A/b so I know when I find there is a problem with the paint the first cause of action for me was to turn the pressure down ( again to some paints this works ) but I have heard that higher pressures can work with paints but it depends on the type of paint. I've noticed tha as you say Tamiya likes it wet and seems to dry before getting onto the model hence I thin down more but then the density of the paint doesn't seem to go down evenly ( I know I'm still learning and learning )
Robert

Don't worry Robert, this isn't the first time that I've heard of this. Unfortunately some things seem to become accepted as gospel!


I've sprayed most brands of paint (not Gunze) & none of them have any problems at pressures of 30-35 PSI. In fact there's a lot of good reasons why higher pressures make an airbrush work better. Ensuring proper atomization is one. Less overspray is another.


A lack of practice with getting a good 'trigger finger' is another area that gets forgotten - this is what controls the paint flow, not the indicated pressure on a gauge.


People might be surprised with the results they get by cranking that regulator up a bit!

[Robert1968]

Don't worry Robert, this isn't the first time that I've heard of this. Unfortunately some things seem to become accepted as gospel!
I've sprayed most brands of paint (not Gunze) & none of them have any problems at pressures of 30-35 PSI. In fact there's a lot of good reasons why higher pressures make an airbrush work better. Ensuring proper atomization is one. Less overspray is another.


A lack of practice with getting a good 'trigger finger' is another area that gets forgotten - this is what controls the paint flow, not the indicated pressure on a gauge.


People might be surprised with the results they get by cranking that regulator up a bit!

Well my hand can only go so fast ( with the brush at present ) Hahahahahaah

[Guest]

Thanks chaps...may I ask please , is there a 'system' to the use of the air/paint trigger. Ie should air start before paint...might this be what I'm doing wrong?

[Guest]

Always depress the trigger first to get an airflow John & then add the paint.

[Guest]

AH! Must stop myself from that manthing of never reading instructions...ops:

[Guest]

...there are instructions???