Help

[Ottopv]

I have a cheap generic airbrush dual action  which I’m struggling with I know I should probably bite the bullet and buy a decent one but I’m new to the hobby and not sure I want to splash the cash yet

anyway the problem is lack of paint flow  if I put my thumb over the cup and seal it  it works a treat even just getting water through is a problem any ideas been cleaned numerous times makes no difference 

thanks paul

 

[bmwh548]

If you put your thumb over the paint cup and seal you will have zero paint flow as you'll be trying to create a vacuum inside the cup. Is it possible you're confusing some of the terms?

[Ottopv]

@bmwh548Thanks for reply but no if. Put my thumb over the paint cup the airbrush works great take thumb away virtually no paint  if I just rest on top same issue but push thumb and seal off it works great, probably just a piece of junk I have noticed today that the nozzle is no way central to the air cap  and the needle certainly doesn’t look like a precision piece 

     

[bmwh548]

I'm not saying I don't believe you...it's just that it contradicts physics. If you look at an airbrush that has a lid for the paint cup you'll notice a small hole in that lid. That hole is there precisely to let in air that replaces the paint being "pulled out" of the airbrush by the airflow going on at the front of the airbrush. If that hole is covered (or if you seal the paint cup for some reason) air can't go inside the paint cup so paint can't exit the airbrush.

Do you have bubbles in the paint cup? Is it behaving like this with paint or is it doing the same thing with water? Is it one of those with multiple set of nozzles and nozzle covers? Is the needle actually moving when you pull on the trigger?

[Ottopv]

Sorry for late response  there wasnt bubbles in paint cup but there is now been stripped down so many times now   I think it probably isn’t worth persevering with 

it is a cheap generic brush and not worth the hassle it has made me realise I want to be able to airbrush so I think I’ll bet the bullet and buy a proper one question now is which one certainly don’t want to break the bank but I want something to work and last any suggestions 1/24 cars and 1/12 bikes

[bmwh548]

I've bought an H&S Ultra 2in1 a few years ago, it was the best purchase for me. PTFE seals mean you can use lacquer paints and thinners, the nozzles are big so you can clean them up without the fear of losing them... I highly recommend getting the CR type needle cap (the prong type), it makes life easier and the quick release with the MAC valve built in. Not sure how much it would set you back for the whole thing, probably 100 pounds? 

 

PS: I paint model cars almost exclusively from 1:43 to 1:18. 99% of the time I use the 0.4 needle-nozzle combo.

[lesthegringo]

My experience of the cheap airbrushes has been good - I have a load of them as I do stuff where I use multiple brushes with different colours for doing stuff like jet exhaust, so I can quickly swap between them. While not as good as an expensive one (more later) I have found that for at least 90% of my work they are fine, and with a bit of effort can be made to work very well

 

If the paint is not coming out unless you are blocking off the paint cup, my suspicion is that the needle nozzle is either slightly loose, or has a crack in it so that the air is being pushed slightly into the paint cup rather than it creating a depression to pull the paint through the paint nozzle. I have seen this a number of times. If you have stripped it down to clean it and it is the type that has a little o-ring between the nozzle and the body, if you have cleaned the brush with harsh solvents it can swell the o-ring - when you assemble it again, you think the nozzle is tight, but as the solvent evaporates, the o-ring shrinks back and allows a leak.

 

As for good (i.e. expensive) airbrushes, yes, they are better. Generally they can give a finer, more consistent spray pattern, are easier to clean and have a smoother action. I like the Creos 770 as a good balance of value for money.

 

But if you want to persist with the cheapo ones, by cleaning them and making sure that they have no burrs, rough edges, has a straight needle and properly centerd nozzle, polished trigger parts, they will do a great job for the money. they can be variable in build quality though, and I have to say that though I have 12 of them bought as a job lot, selective assembly has left me with seven 'good' ones and 5 that I use only for rough work like primers due to them not being capable of very fine work.

 

Hope this helps

 

Les

Edited August 24, 2020 by lesthegringo