Good Airbrush/needle size for spraying lacquer???

[crowe-t]

I have an Iwata Eclipse HP-CS and recently decanted Testors MM Custom Lacquer System paint and shot it with the airbrush.  It seemed to  leave a grainy surface.  The Iwata HP-CS has a .35 mm needle but can be changed to a .50 mm needle.  Maybe the needle is too small.

Does lacquer require a larger needle size?  if so what's a good needle size and/or airbrush for spraying lacquer? 

I do like the Iwata airbrushes.  

Edited April 26, 2016 by crowe-t

[astroracer]

What you are seeing is a paint, formulated to be sprayed from a rattle can, being sprayed through an airbrush.

The 1st thing I will point out is, as you decant the paint, you are immediately losing the volatiles. The ingredients that help the paint to spray smoothly AND lay down and flow a bit before setting up are probably nearly gone by the time you get it into your airbrush and actually spraying. I would suggest decanting then adding a bit of laquer thinner to get the spraying consistancy correct for the airbrush. This will take some experimenting on your part to learn what amount the "new" paint likes...

 And, while your are at it, experiment with the nail polish. This stuff mixes and sprays just like laquer (it is laquer) and is a lot cheaper to buy at the dollar stores or Big Lots.

Mark

Edited April 26, 2016 by astroracer

[935k3]

I have the Eclipse. The change to the .5mm was good. It makes a great all around brush. All paints need thinned properly with any size tip & needle. i ending up getting the Iwata Revolution with the .5mm standard. Now I have the best of both sizes and do not having to change tips and needles. If you decant Tamiya Sprays they need thinning, their Laquer Thinner was made for this and works well with all decanted paints.

Edited April 26, 2016 by 935k3

[Pete J.]

What you are seeing is a paint, formulated to be sprayed from a rattle can, being sprayed through an airbrush.

The 1st thing I will point out is, as you decant the paint, you are immediately losing the volatiles. The ingredients that help the paint to spray smoothly AND lay down and flow a bit before setting up are probably nearly gone by the time you get it into your airbrush and actually spraying. I would suggest decanting then adding a bit of laquer thinner to get the spraying consistancy correct for the airbrush. This will take some experimenting on your part to learn what amount the "new" paint likes...

 And, while your are at it, experiment with the nail polish. This stuff mixes and sprays just like laquer (it is laquer) and is a lot cheaper to buy at the dollar stores or Big Lots.

Mark

Well said!  The graininess is due to it not having time to self level.  This is solved two ways.  1) add the correct thinner. 2) hold the brush closer to the surface.  Both will get the paint to the surface with more solvents still active, however by moving closer, you will also shrink the size of the spray pattern and put more paint on.  Thus if you want to lay down thin layers the best solution is to thin the paint for the distance that you normally paint from.  A larger needle and tip is nessesary for the size of the grains of pigment.  Very fine pigments such as inks need very small needle/tips.  Heavier paint such as automotive lacquers have larger grain and need larger needle/tips.  Most acrylics also need a larger needle/tip combination.  Finding a happy medium that works with most of your paints is the challenge.

[crowe-t]

Thanks guys for the advice.  However I intend to use other lacquers in the future and not just decant paint from spray cans.

Can someone recommend a needle size for lacquer?  

Is .35 mm or .50 mm big enough or should I go to another airbrush with a larger needle size?

[Pete J.]

Ok, you can't select a needle size based on the solvent you are using.  It is not the solvent that determines the size of tip used.  It is the size of the pigment grains.  A better example would be to talk for a moment about acrylics.  Model acrylics tend to have very small pigment size.  Acrylic house paint has very large pigment sizes.  You would never ever get house paint through the typical airbrush, but both are "Acrylics".  Same with Lacquers.  The only way to know is to get the paint you want to spray and try it.  As to the needle, having an extra needle and tip will never be a bad thing and they are not that pricy.  I would suggest get both and try them on the different paints that you use and see how they work.  This is like discussing compressor pressure.  No one can give you a pat answer.  You have to work with what you have and try it until you get what you works for you. 

By the way, I have four airbrushes and each of them has a different size tip, uses a different pressure and feed system.  They all serve a purpose.  Not a single one of them does everything I want well, thus multiples.  Oh, and  two of them have three different needles and tips each.  This probably doesn't give you a direct answer to the question you asked, (Is .35 mm or .50 mm big enough or should I go to another airbrush with a larger needle size?) but it is the answer.

Edited April 26, 2016 by Pete J.
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[crowe-t]

Thanks again Pete for all your input!  I'll most likely pick up the .5 mm needle and I'll continue to try different paints and see what works best.

[Mike Kucaba]

Thin your lacquer with a slow evap rate thinner. Find this at a regular automotive paint supplier  I use PPG DTL 105 and it works great. I douby ou'll find this at the hardware store.

[fiatboy]

To put my 2 cents in: I recently decanted Tamiya laquer and after letting it sit in an open jar (for 6 hrs.?) and I had to add a LOT of laquer thinner to get to the (thin)viscosity AND turn the pressure way up.  I probably got at least 4 ounces of paint out of that aerosol can after it was thinned way down.

[peteski]

To put my 2 cents in: I recently decanted Tamiya laquer and after letting it sit in an open jar (for 6 hrs.?) and I had to add a LOT of laquer thinner to get to the (thin)viscosity AND turn the pressure way up.  I probably got at least 4 ounces of paint out of that aerosol can after it was thinned way down.

There is a lot of propellant (propane or butane) dissolved in the paint in aerosol cans.  That has to degas before you can use that paint for airbrushing. I never totally leave the jar open - I put the lid on but leave it loose.  Decanted paint is usually thicker in consistency than what you normally use in an airbrush.

[fiatboy]

Yeah, Peteski.  I have a 3-oz. bottle I got from "Chicago Airbrush Supply".  I successfully decanted the entire spray-can and after I thinned it out properly (it is still too thick) it filled the 3-oz. jar, and it is still too thick.  I did successfully airbrush with it but I had to turn the pressure way up ( 40 psi).  Hope it helps.

[peteski]

Yeah, Peteski.  I have a 3-oz. bottle I got from "Chicago Airbrush Supply".  I successfully decanted the entire spray-can and after I thinned it out properly (it is still too thick) it filled the 3-oz. jar, and it is still too thick.  I did successfully airbrush with it but I had to turn the pressure way up ( 40 psi).  Hope it helps.

Thinning paint for airbrushing, the air pressure and needle opening are all something that everybody does a bit different: a skill that you learn on your own.  If the paint is thick, you could try to open the needle up more instead of raising air pressure. You might find a a setting which will work for you. Or just add more thinner.

[fiatboy]

I've been told that the 'needle opening' only controls the 'width' of the actual paint-spray coming out of the tip.  So if you open the needle more, you will get a wider spray, and if you close it, you will get a narrow spray.  For me, the viscosity of the paint is (almost) everything.  I very rarely change tips.  But if the paint is thick, go to a bigger nozzle, and if the paint is too thin, go to finer or smaller nozzle.  To check the viscosity, I mix it good and then tip the paint-jar so you can observe how the paint 'swirls'.  

[dshue76]

Unless you have a paint with gigantic metal flake your lacquer will go through a ,25mm needle and tip. I use a Paasche Talon and my preferred needle and tip are .25mm for oil based enamels,  water based craft acrylics, and lacquers. Your problem I believe has to do with technique, air temp, spray pressure or how you are thinning the paint. I know for a fact that when I have the issue you are asking about it is due to the paint being too thick.and I would still get the same results if I would try a .38mm tip.The tip size is more about spray pattern and volume than particle size.  All decanting process' require adding thinner since while you have to let the entrapped propellent escape, the thinner is evaporating. Not adding thinner will cause the paint to dry on and in your tip. When this happens pour the paint out of the cup and re mix then clean the needle and tip. Mixing in the cup after paint starts drying in the tip has never worked for me.

Practice to get the hang of thinning and to see the effects of too thin vs too thick. The plastic "for sale" signs and such make for great target practice. The typical practice lessons for airbrushing, dots of various sizes and lines of varying widths, and start stop points also help you understand thinning.

Edited May 4, 2016 by dshue76