No paint from airbrush

[ColinK]

Hi, I’ve just set everything up to do some painting. I’ve two airbrushes and am using Vallejo Model Air paints. Both airbrushes are emitting air from the nozzle, but no paint. What am I doing wrong?

 

Both brushes were cleaned thoroughly after their last use.

[Spitfire2865]

Did you check the tips are clear?

Is the paint thinned properly?

What pressure are you spraying at?

[Ian Morgan]

By 'cleaned thoroughly', did you mean complete dismantle and removal of needle?

[brossard]

May sound like obviousness but do you have a regulator fitted?  Acrylic paint can dry in the nozzle, I recommend Tamiya (or similar) Paint Retarder.

 

John

[ColinK]

Thanks for your quick replies chaps, a big help. I got the job done.

 

Yes, I did dismantle them last time I used them and I have a regulator on my compressor. Pressure is about 12psi if the gauge is correct, it seems to work OK on that setting.

 

I think I’ve found the problems. I dismantled both airbrushes, had a good look at the bits, cleaned, reassembled and got them to work.

First, I think the Model Air paint which I thought was airbrush ready needed a bit of thinning - I added a bit of the correct thinner and it flowed much better.

Second, inside the airbrush the paint flows from the cup down into a recess which the needle goes through. It then goes through a small hole along with the needle to the nozzle. I think some paint had dried inside that hole - but I can’t see a way of cleaning that hole. I cleared it this time with a quick squirt of Airbrush Reamer. Is there a better way (my airbrushes are middle range)?

 

I’m also wondering if something is going on when the airbrushes are packed away. I spent a lot of time cleaning them last time following all the advice on here and they were spotless. But today I noticed some marks on the needles, not quite rust but as if something had been touching the needle inside the airbrush. Or should I leave all the components to dry before reassembling?

[Greengiant]

I run model air at 20-25 psi, sometimes s few drops of thinner if the paint has been hanging around a while.

Air brush cleaner normally sorts things out, cellulose if really stubborn

 

Martin

[njee20]

I use a bit of Autosol metal polish on the needle with a cotton bud. I imagine people will say that’s a terrible idea, but it removes any tarnish marks, which seem to have a more detrimental effect than any abrasive.

[PaulCheffus]

I use a bit of Autosol metal polish on the needle with a cotton bud. I imagine people will say that’s a terrible idea, but it removes any tarnish marks, which seem to have a more detrimental effect than any abrasive.

Hi

 

I use this periodically on my airbrush needle

https://www.amazon.co.uk/Iwata-Medea-Super-Lube-Airbrushes-2ml/dp/B07HJ4DM3Q/ref=sr_1_2?ie=UTF8&qid=1543402221&sr=8-2&keywords=iwata+super+lube

 

Other suppliers are available.

 

Cheers

 

Paul

[katwigan]

In the full size world of spray painting ( Wagner, Graco etc ) we always left a film of Diesel fuel on needles, seats and ball valve assemblies to prevent corrosion.It flushes out or  wipes off easily and doesn't evaporate like the pump storage fluids that the aforementioned companies sell.

Perhaps worth considering for long term storage particularly in cold ,damp environments.

Just a thought.

Kevan

[Mick Bonwick]

It's not just 'after use' you need to clean an airbrush when using acrylic paint, you need to maintain cleanliness during use as well. Even if using airbrush-ready paint, such as Vallejo Model Air, you should aim to flush through the airbrush with acrylic thinners on a regular basis, especially if you're putting it down for more than 5 minutes. The quick-drying property of acrylic paint is a mixed blessing when using it in an airbrush.

 

There are 'flow improvers' and 'retarders' available to help with the process of preventing paint drying inside airbrushes, but if that's what is needed then you might as well use enamels. There is something to be said for drying components before reassembling, but most of all they all need to be spotless. The inside bits that you can't reach or see can be cleaned by foaming cleanser for acrylics, or liquid reamer for enamels.

[Guy Rixon]

I also find that Model Air paints are too thick to spray from the bottle. This is true even with higher pressure.

 

I clean my airbrush after use in an Ultrasound tank with soapy water. The body (with nozzle attached), the needle, the nozzle cap and the paint cup all go in there, but not the air valve or needle-chucking gear. This removes a lot of waste paint from the body. The slight risk is that the vibration can unscrew the nozzle, which is then easy to lose. I spray through with clean water before painting.

[ColinK]

Thanks everyone, I was painting three G scale buildings, took about an hour with a slightly different colour on each one. I never considered cleaning the airbrush during spraying (I didn’t change the paint, just added more white or brown to alter the hue).

 

I’ve learnt a lot from everyone’s posts.

 

I’m wondering now if I need to ask Santa for a quality airbrush instead of the cheaper ones I’ve been using.

[Tony Teague]

I’m wondering now if I need to ask Santa for a quality airbrush instead of the cheaper ones I’ve been using.

 

You'll still ned to keep it clean!

[Ross34]

I'm still a bit wary of using acrylic in my airbrush but I found the Com-Art range to be very good.

 

https://airbrushes.com/product_info.php?products_id=20811&osCsid=9bv15t1mrfdk1g0lnu90r75rg0

[ColinK]

Another day, another disaster.

 

Got all the kit out and set up. Took both airbrushes apart to check they were clean, yes.

Blew a little thinners through, everything fine.

Started first using the airbrush with the built in paint cup, it has a 0.3mm output according to the box. Very splattery at first, a gather that could be due to the thinners making the paint too thin. Upped the air pressure and blew through all the too thin paint. Lowered the pressure back to normal and painted fine for about 5 minutes. Suddenly paint stops flowing, but air stil coming out (yes there was plenty of paint in the cup. Dismantled and cleaned everything, no obvious problems. Reassembled, still air and no paint. Blowback check with finger over nozzle OK.

 

Switched to other airbrush, this one uses paint jars that screw into the side and is 0.4mm nozzle. Similar experience to above, other than only 2 minutes before paint stopped flowing.

 

I also had a problem with the compressor at one point. I could only adjust the pressure downwards, not increase it. Dismantled the valve (its just a spring on a diaphram) and reassembled it. Now working fine.

 

I’m still unsure what is causing the paint to stop flowing. Could it be my cleaning not good enough (but dismantled and got everything spotless)? Could it be poor paint that has tiny lumps that cause the blockage?

Two things I have noticed,

First, at the spraying end of the airbrush the needle goes through a small hole, it is very difficult to get this hole clean ad there is no way of accessing it. All I can do is blow thinners and cleaner through it.

Second, on the airbrush with the built in paint cup, there is a recess where the paint drops into the air and needle. On cleaning after use today there seemed to be a bit of tiny debris in it which I managed to pull out. I suspect this may be hairs off the cotton buds I’m using to clean it.

 

So I’ve wasted about 2 hours and the house smells of thiners and airbrush cleaner. I ended up brush painting instead.

 

Any advice appreciated.

[Guy Rixon]

Are you still using Vallejo paint? I find that it does clog up during painting, and I try not to spray it nowadays. It seems to clog much more readily than enamel paint and other brands of acrylic paint. I suspect it's a combination of quick drying and larger pigment particles.

 

Suggestions:

 

- Ditch the Vallejo and change to Tamiya acrylics (which I find less troublesome when spraying), or enamels.

 

- If staying with Vallejo, don't thin with water. Use either IPA or Vallejo's own thinners (which are likely mainly propanol). White spirit is probably not appropriate.

 

- Add a paint retarder to delay drying out.

 

- Use higher pressure. 15-20 psi is good for optimal paint, but going up to 30 psi may help with imperfect paint.

 

- When it clogs, quickly take off the nozzle cap (not the nozzle itself), withdraw the needle, and wipe the end of the nozzle with a tissue. You might be able to shift the clod of dried paint that's blocking it. If you can get it so that it drools a line of paint into the tissue then it should be clear enough to spray.

 

- If the paint clogs a cheap brush it will probably do the same to an expensive one.

 

HTH.

[Mick Bonwick]

Don't get cotton buds anywhere near the inside of your airbrush! They should only be used for cleaning the outside.

 

Your problem is being caused by a blockage, that's for certain, and you've identified one cause. I now have some questions for you:

 

• What make and model are your airbrushes?
• What is the thinner you are using?
• Do you have any foaming cleaner, or other airbrush cleaning fluid as opposed to thinner?
• Do you have any wire cleaning brushes?

Answers to those questions will help to determine your next step(s).

Edited November 29, 2018 by Mick Bonwick

[ColinK]

Thanks for all the replies, they really are appreciated. One of the main benefits of RMweb is that lots of us help each other (I’ve helped people when I can). Answers in the text below.

 

 

Don't get cotton buds anywhere near the inside of your airbrush! They should only be used for cleaning the outside.

 

Your problem is being caused by a blockage, that's for certain, and you've identified one cause. I now have some questions for you:

 

 

• What make and model are your airbrushes?

   

  Unbranded ones that several traders sell at exhibitions, cost about £40 each.

• What is the thinner you are using?

  Vallejo’s own thinners with their paint.

• Do you have any foaming cleaner, or other airbrush cleaning fluid as opposed to thinner?

  Vallejo’s airbrush cleaner and some unbranded cleaner that came with the airbrushes.

• Do you have any wire cleaning brushes?

  No, didn’t know about them.

Answers to those questions will help to determine your next step(s).

Interesting that I have used Vallejo paints from the same pack many times before without any problems.

I’ve also sprayed with railmatch enamels, no problems except the stink in the house.

I’ve also used loads of the cheap acrylics that came with the airbrushes, they worked fine.

Recently I’ve started using Tamya acrylics (my local model shop in Carnforth sells them) and I find them very good for brushing, not tried spraying them yet. Indeed I’m using them as much as enamels now.

[Irish_R_M]

I've been this soldier, and I'd be willing to wager it's the nozzle itself that's causing grief. No matter the amount of mid spray cleaning or after spray cleaning you do, the inside of the nozzle attracts tiny layers of acrylic, flying through at the rate of knots dries if you put the airbrush down. 

 

Get some paintbrush restorer from rustins, put a drop into the removed nozzle, and after a minute or two, dig around with a spare airbrush needle. The world and all of gunk will come out. 

 

I still use acrylics and mid range airbrushes and find a good dismantling after and thorough clean is worthwhile. Model Air paint does behave oddly if unused for a while. 

 

RM

[ColinK]

I haven’t any Ruskins, but tried dismantling them then putting putting a few drops of Brush Magic into the holes where the paint goes, leaving it a few minutes, then ...

 

On the airbrush with the paint cup, I put the clean needle back in, then pulled it out, there was some paint on the needle. Did this a couple of times after which it came out clean.

 

On the airbrush with the paint jar, loads of paint on the needle, took a while to get it coming out clean. This brush has no practical access into the area where the paint and air mix.

 

I haven’t rinsed them out yet to see if it softens any more paint inside.

 

I also examined both needles under a magnifying glass, neither tip is perfect, but they do seem in reasonable condition.

 

So from the above it does suggest that the problems include,

- paint sticking inside the nozzle, but there is no way I know of to clean it except for dropping in paint cleaner.

- hair off cotton buds getting inside (my fault)

- perhaps the paint too.

 

Frustrating but some progress.

[Campaman]

Some of the small Interdental tooth brushes are useful for cleaning the small openings, the ones with the actual bristles not the rubber ones.

[ColinK]

Hopefully a result, due to everyone’s helpfull replies.

 

Went out on various errands, including visiting the Model Shop on Carnforth station where I got some more Tamyia acrylics and their thinners.

 

After I got back I had another go at the airbrush with the paint cup, flushed through water and cleaning fluid. Found a interdental brush in the bathroom and poked about with it. Got some dried up paint and some tiny fibres (probably off the cotton buds I had used earlier) out of the nozzle. The paint cup does not detatch so its very difficult to access this area, but I managed it. Flushed through more water on fairly high air pressure and it came out clean. Added Tamyia thinners to some of their paint and painted a wagon without any problems, indeed got a very good finish. I gave it lots of coats to see if the airbrush jammed up, but it didn’t. So fingers crossed I now know what caused the problem and how to avoid it in future.

 

I had a similar go at cleaning the airbrush with the paint jar, this is much more difficult to clean as there is no way of accessing the back of the nozzle. I did get some dried paint out, but I’m not sure its totally clean due to the poor access. I flushed it with water and cleaner both of which came out clean, but didn’t try any painting with it. After reassembly the air valve was sticking, I’ve had it apart and reassembled and hopefully its OK now.

 

Probably no painting now for the next couple of weeks due to some building work on the house, but I have got all the parts of my buildings painted ready for assembly.

 

I’m still wondering if I should replace my basic airbrushes with a higher quality one which can be taken apart and cleaned easier. Perhaps if I see a good offer somewhere.

 

Thanks again guys.