One type of paint is fine the other I can't get to work.

[Stuart]

I have a question I started airbrushing about a week ago trying to do lexan RC car bodies. I was using Testor "Pactra" Racing Finish. It's a lacquer paint and after reducing sprayed wonderfully, great control no clogging issues just very potent aroma.
So in order to practice technique I thought it wise to use some paint that was a lot less toxic. I went to my local arts and crafts store and picked up a 6 pack of the spectra tex opaque and some of their brand cleaner. I printed out a bunch of the practice PDFs from the website and eagerly set up.
Now with this new spectra-tex I am having horrible flow issues. It will not keep a steady spray of paint. I tried it straight out of the bottle and different ratios reduced. I could not practice at all today as I was trying to solve this problem. I have 3 brushes, all had the same issues, when I tried using the other paint "pactra" it was smooth again.


Any ideas would help a lot I would really like to get to painting.


Heres what I was using.
iwata eclipse HP BPS .5 needle (3 different brushes same prob, took apart and cleaned)
psi I tried several ranging 15-80
spectra-tex opaque black (reduced and straight from the bottle)


i can't think of any other variables, I read about pulsing and checked seals, needles, and it didn't make sense to me that one paint works and the other does not.




Stu

 

[Madbrush]

can I assume that the "Pactra" paint is oil based? oil based paints generally have finer pigment making them easier to spray even with finer tips.

Water based paints have heavier pigments but with the right handing can be sprayed through tips as small as 0.2, there can be problems with these paints thickening or drying to some extent during storage, have you tried filtering these paints? and how much are thinning? 10 - 20 parts thinning for these paints is not uncommon, I would suggest playing around with different ratios to find one that suits you.

I'm into model aircraft myself and frequently paint these but on another (model build) forum I see others with RC cars using Tamiya colours either from a rattle can or through an airbrush and in both cases to stunning effect.

If you had good results form the Pactra paint, why not continue with that and use a mask, you should really use a mask even for water-based/acrylic paints they still contain harmful substances.

If you have some completed bodies, do post them, it would be nice to see what you do.

 

[Mr.Micron]

when switching from lacquer to waterbased , you really need to do a major cleaning of the brush first.
I have ran spectra-tex through a Eclipse CS and a Micron with both the .23 and .18 set up with no issues.
It could also be the needle bearing , Where and when did you buy your Eclipse HP BCS? Some of them came with a rubber needle bearing instead of the teflon one. Which means the lacquer and the lacquer thinner could have messed up the bearing if you have the rubber one instead of the teflon.

 

[Stuart]

Hey Mad, yes the pactra is an oil based, I think it would help me if I did some research on the types of paints. I was reading about some people straining the paint, I will look around and see what they are using to strain and give that a shot... I have no idea how long that paint was sitting on the shelf before I purchased it. Your right about the mask, I have one and if I am going to get into this hobby seriously I should make wearing it a habit. As far as thinning I will try a more methodical trial of thinning today after I break down the brushes and do a deep cleaning today.


Mr. Micron, I actually have 5 of the Eclipse HP BCS they are all atleast 10 years old. I have not fully broken them down but that will be my next step. I will check to see if they have rubber bearings and if they do it sounds like I should replace all of them to teflon.

Since I have multiple brushes would it benefit me to keep some for strictly oil based and the others for water based.

You guys are really sheding some light on this for me and lifted my spirits a bit, I was quite frustrated last night.

Thanks

 

[Mr.Micron]

How far are you from Coast Airbrush out in Cali?
I would put the teflon in all of them and being 10 years old they are more than likely rubber ..What happens is the rubber breaks down with solvent paints.
But being you have 10 of them you can set one up for straight water.

 

[Madbrush]

Hey Mad, yes the pactra is an oil based, I think it would help me if I did some research on the types of paints. I was reading about some people straining the paint, I will look around and see what they are using to strain and give that a shot... I have no idea how long that paint was sitting on the shelf before I purchased it. Your right about the mask, I have one and if I am going to get into this hobby seriously I should make wearing it a habit. As far as thinning I will try a more methodical trial of thinning today after I break down the brushes and do a deep cleaning today.


Mr. Micron, I actually have 5 of the Eclipse HP BCS they are all atleast 10 years old. I have not fully broken them down but that will be my next step. I will check to see if they have rubber bearings and if they do it sounds like I should replace all of them to teflon.

Since I have multiple brushes would it benefit me to keep some for strictly oil based and the others for water based.

You guys are really sheding some light on this for me and lifted my spirits a bit, I was quite frustrated last night.

Thanks

Your welcome Stuart, that's what forum is all about and believe we all know that frustration,

As far as straining your paint goes, that's something you should make a habit of, your airbrushes are so delicate it pays to do all you can to protect them, I generally mix my colours in handy squeeze bottles, once my colours are mixed I cut a small double square of old pantihose and place that over the bottle neck before putting the lid on, this is in addition to straining before pouring the paint into the bottle, and it means your straining the paint as you go.

You might want to try Schminke aerocolour, this is more like an ink or dye than a paint and has finer pigment, I checked out other forum for info and a lot of the guys there say it's ideal for their lexan car bodies, you could maybe buy a small bottle of black and see how it goes.

As I said let us see what your doing.