Paint not spraying...

S

Scottydee

Guest
Hi!
As some of you who I've chatted to on my introduction thread will know, I use my airbrush for applying conductive paint prior to electroplating.
I've been having a problem with getting the paint to actually spray. I'm using a 0.50mm nozzle and have the pressure turned up as far as it will go on the little compressor that I have (around 4 bar), but when I pull back for paint, I only seem to get a little coming through. If I move the lever back and forth I do get paint coming through, but it isn't ideal.

Should I try to adjust the needle to it moves back further? I might be able to thin the paint, but this might affect the coverage as it contains pure silver. The supplier I use for the paint suggests using an airbrush (they use one) so I know I should be able to use it, but maybe I'm missing something simple but important!
 
Hi scotty
Sounds like a blockage in the nozzle, the stuff ur using might need a bigger nozzle as well as the stuff ur using sounds like its thicker than proper AB paints. There are many ways to clean a nozzle and everyone on here has their own way of doing it. Me, i use the tip of the needle to GENTLY scrape around the inside of the nozzle after letting it soak in hot water for a while, the method i use can be costly if you damage the nozzle or needle or even both. Have a look thro the forum or search for nozzle cleaning and you will see lots of different ways and pick which is best for you
 
It might be that the paint is too thick or the nozzle is clogged (as indicated above). See if you also have the problem with water. If that spray's fine chances are it's just the paint (though as water is not as thick as paint it doesn't rule out a dirty nozzle).

Reducing your paint might not help by the way (probably not even in this case). Thining the paint might improve the flow but the pigment and silver particles will stay exactly the same and chances are that a 0.5 is just too small to handle those silver particles resulting in them building up in the nozzle and clogging it up.
 
Thanks guys. The airbrush is brand new so I'm sure that it's already clean - I've had detergent in and fired it up with my finger on the end so it blows back into the reservoir to clean it.

What sizes do needles/nozzles go up to? And do I have to get one that's model specific or are they standard for all (most) airbrushes?
 
Was it working to start with and then playing up??? If so then its most likely the nozzle. As hassje has said the silver particles could be to large, as for nozzle sizes and type of brush i wouldnt be able to advise but sit tight n someone will answer it for ya mate [emoji4]
 
If I adjust the needle so that it's too far back, then it works - like wise, I applied extra pressure by taking off the lid and blowing, and that worked too - although not an ideal or comfortable position to spray in!!!
 
Thanks guys. The airbrush is brand new so I'm sure that it's already clean - I've had detergent in and fired it up with my finger on the end so it blows back into the reservoir to clean it.

What sizes do needles/nozzles go up to? And do I have to get one that's model specific or are they standard for all (most) airbrushes?

If you have sprayed paint through it once it's no longer new and no longer clean :). Putting flakes (or in this case silver particles) through it even once can be enough to ruin a nozzle if those particles are too big. Putting cleaner in or blowing back doesn't mean the nozzle is clean. Those particles stick in a nozzle. If you take out the nozzle and keep it against a light you should see a nice round hole when looking through it (spray water through without the needle in it before that else, the needle will just push any residue against the nozzle making it apear clean).

Nozzles for an airbrush go to about 0.6 / 0.7 after that you'll probably get into the "paint booth" category of guns (also keep in mind that the bigger the nozzle the more capacity your compressor will need to have)

I'd look up the tech sheet or contact the fabrikant of the paint to figure out what size nozzle they recomend for the paint you are using (might also be on the bottle/can). Keep in mind what they indicate will probably be the absolute minimum requiered to have a chance to get that paint through :p
 
If I adjust the needle so that it's too far back, then it works - like wise, I applied extra pressure by taking off the lid and blowing, and that worked too - although not an ideal or comfortable position to spray in!!!

Definetly sounds like blocked nozzle, clean it see what happens, i know you think that cause its new it couldnt be that dirty but you would be surprised at how quickly it could get a blockage especially if your using stuff thats no AB friendly
 
Thanks guys. The airbrush is brand new so I'm sure that it's already clean - I've had detergent in and fired it up with my finger on the end so it blows back into the reservoir to clean it.

What sizes do needles/nozzles go up to? And do I have to get one that's model specific or are they standard for all (most) airbrushes?

I have one airbrush which is 0.8 I use it just for priming, I'm not sure if bigger is possible for an airbrush specifically yours.

It was because of the metallic aspect of your paints that I suggested a mini spray gun in your other thread, these ideal for your purpose since your not looking for detail, these go up to 1.2mm but I think 1.0 would suffice in your case.

Bear in mind that larger nozzles also mean larger volumes of air required, this could cause your compressor to overheat if has lower delivery characteristics.

As mentioned thinning the paint doesn't thin the pigment, also over thinning can pigment separation making your paint useless, so I'm pretty sure as Haasje said, it's the silver particles that are causing your problem, it's similar to 20 people trying to get through a door all at once, the smaller the door the more difficult that is.

Have a look around at mini spray guns, they are generally a lot cheaper than a decent airbrush and are certainly less fragile.
 
Why not ask the guys who you bought the "Paint" from what they use or what they suggest?
We are stabbing in the dark here because I don't think any of us appreciate what you are trying to put through your AB.
 
Why not ask the guys who you bought the "Paint" from what they use or what they suggest?
We are stabbing in the dark here because I don't think any of us appreciate what you are trying to put through your AB.


The suppliers of the paint do sell an airbrush, but it looked very cheap and tacky (the compressor was housed in a plastic case). I'll see if I can find the spec on theirs, and hopefully get it sorted.....silver paint isn't cheap (almost £35 for 10 grams) and I don't want to waste too much if I can help it!

Thanks for all your help so far - it is greatly appreciated.
 
Dosnt matter if its cheap cause i dint think itll be any use to you apart from what is designed for
 
Dosnt matter if its cheap cause i dint think itll be any use to you apart from what is designed for

I don't think that it's one that they have had specifically designed for them, although I'm just waiting for a reply from them on what pressure and nozzle size they are using...
 
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