Help with airbrush

[Panzergrenadier]

Hi,

Been using my new airbrush for a week now. (Double action gravity feed.) Yesterday when I tried to do fine mist it does that for about 2 seconds and then stops. When I pull back on the lever and it starts coming again but then there is too much paint. When I release the trigger and try again everything happens the same way. :angry:
I disassembled it and cleaned it through well and nothing seems to be broken. The needle seems to be straight and the nozzle ok.
Tried to do some painting today and the same problem appeared.

My compressor is a small one but it has a small airtank. I tried different pressures but the result is the same as mentioned above. I dont have a moisture trap as I have used the compressor since christmas with a single action external mix brush and everything has been OK till now.

My main guess is that because the weather is getting warmer here the air is more moist and because the new airbrush is more sensitive to moisture.
I really dont want to buy a moisture trap only to find out that the problem is still occouring. But if I really have to do that then I can't buy it untill monday when the hobby shop opens again.
And to top it all of all the painting has to be done by Tuesday evening for a competition.

So can please anyone help me with this problem? I am really desperate. :(


Best wishes
Siim

[Uruk-Hai]

What kind of airbrush do you use, Siim?

It sounds like the paint isnt thinned properly or perhaps not well stirred? What kind of paint do you use, what do you thin it with and in what ratio?

Could also be the nozzle that isnt tightly fastened, especially if its an Evolution airbrush.

Cheers

[Panzergrenadier]

The airbrush I'm using is a Revell Master Plus IDG 950. It's adouble action brush with a gravity feed cup. But on the box it says in small lettering: ''This Vega model by Thayer & Chandler is exclusivley distributed by Revell AG'' so it is practicall the same as a Vega 1000. A lot of confusing information. :lol:

I use Model Master, Revell and Humbrol enamels. I thin them usually 50/50. I thin them with White Spirit. When the problem occoured then I tried thinning it down to 20% paint and 80% solvent. Still no change.

I believe the nozzle is thightly fastened.
The manual also says that the nozzle and spray head form a unit and when taken apart should be sealed again with wax. I haven't used any wax, should I?


Siim

[mnickolson]

Siim,
I use Model Master and Humbrol enamels but I use a enamel airbrush thinner not White Spirits. Not sure if spirits should be used like that in a airbrush, just mhop

Mike

[brokeneagle]

Siim,
white spirits should not effect your airbrush, I run mine and clean with sprits and it's fine. If you have a moisture problem you would know as your brush would be spitting the moisture out through the nozzle creating water dots on your paint.
If you have cleaned the brush thoroughly, have enough pressure and nothing on the airbrush is bent or broken then it must be the paint mix. Double actions require a much more fluid mix than an external mix.
Hard to advise much else from here without actually using the brush. :)

[Larry Bates]

Siim,

Ian has good advice for your setup. I even run laquer thru my Iwata and it is fine. As far as wax, that is to make the needle slide more easily through the rubber o-ring internally which seals the front where all the air and paint mixing take place. I would say from your description of the problem .... are you aware of how double action triggers work? I really don't know what else the problem would be.

Maybe your paint is old? or has hardened particles in it? you may need to strain the paint.

Larry

[mnickolson]

I guess I am learning something here also. Larry and Ian you thin your enamels with white sprits? Hmm I clean with it and use it with wash's but have never tried thinning my enamels with it. May have to give it a try.

Mike

[Larry Bates]

Hi Mike,

Mineral spirits, white spirits, turpentine, paint thinner , I believe is all basically the same stuff. And the fancy names model paint companies give their products like airbrush thinner, brush cleaner, is the same as paint thinner or turp, etc.... then there is laquer thinner, for metallic paints, and clear coats. Hope that helps.

Larry

[Uruk-Hai]

It seems to me on your description that the nozzle tip might be clogged. Have youve cleaned it properly? Try to clean it more an tighten every screw. Also check gadgets and O-rings.

Cheers

[Panzergrenadier]

Hi,

Thanks guys for all the tips. :)
I will check every element of the brush first thing tomorrow.



Siim

[Panzergrenadier]

Originally posted by Larry Bates@Jun 17 2006, 07:03 AM
Hi Mike,

Mineral spirits, white spirits, turpentine, paint thinner , I believe is all basically the same stuff.* And the fancy names model paint companies give their products like airbrush thinner, brush cleaner, is the same as paint thinner or turp, etc.... then there is laquer thinner, for metallic paints, and clear coats.* Hope that helps.

Larry
I have thinned matt clear coat with White Spirit. One just has to be shure to work quickly. At first it mixes well but in 10 minutes or so begins to form a jelly at the bottom of the cup. I learned it the hard way with my old cheap airbrush. Luckily I managed to clean it. Not going to attempt it again.
Live and learn. :lol:


Siim

[mic bradshaw]

Siim,
It really does sound like a thinner to paint ratio to me. When you change over to the more advanced airbrushes, 50-50 mixes just aren't enough. I run about 80: 20 or 90: 10 through my double actions. It takes a lot more passes to get a solid coat of paint, but it is more than worth it. To me it sounds like your brush is drying out at the tip as you use it. What pressure are you running at as well? Around about 25 psi is the trick. As a higher pressure will make the tip dry out faster as well.
I have found that everytime I have changed to new airbrushes it takes about a week or so to get all the factors right. You just have to keep trying. If you do change something, do it one factor at a time. Test the brush on a piece of paper and if that does not work try something else. To be honest and I know you have said you didn't want to get a moisture trap but they really are worthwhile.

Regards

Mic B

[Uruk-Hai]

Actually Ive never thinned my paint more than 50/50 and never had problems. I use mostly Tamiya and occasionally Humbrol and Vallejo.

Cheers

[Larry Bates]

Siim,

Is your matt clear coat testors? if so you need to thin with laquer thinner! That is why you are getting a gel consistency to it, it is laquer based. Also, clear coat can be thicker than regular enamel paint, and take even more thinning. Also, 25 psi is probably the max you should spray at with enamels, especially thinned down to 80 or 90 percent thinner.

Larry

[Panzergrenadier]

Larry,

The matt clear coat was Revells (or was it Humbrols, can't remember). Haven't used clear coats for quite a bit now. (Haven't gotten any work up to that stage.)


And I usually work at 25-10 psi. The thinner the lower.
The weird thing is that I managed to do one colour of the camouflage on my FLAK and then cleaned the brush and the next day the bad things started.



Siim

[Larry Bates]

Hmmmmmm,

Well, it seems, by your comments that you are having a paint, or paint mix issue. As, your paint starts to spray fine, then clogs at the tip, and the clear forms a gel in the bottom of the cup. It sounds like you may be using the wrong thinner, or your paint has gone bad. If you live in and area that is very humid or damp, this may have an adverse effect also. In which case you should get a moisture trap, or wait for a dryer time of the year to paint.


Larry

[Panzergrenadier]

Hi,

Yes I think I have to buy some stronger thinner. I think my hobby shop has the Humbrol kind.
I will stick to spraing clear coats with my old cheap airbrush.


Siim