trouble with airbrushing - Airbrush BD-130A

[Rev]

ok so last year I bought an iwata studio series compressor and Airbrush BD-130A from airbrush pro.

The compressor was expensive, the airbrush not so much. But regardless, it'd gotten good reviews for a beginners tool.


Now, I can't get consistent results EVER.

I can spray consistently for about 3 minutes before the flow dries up.

This happens regardless of how much I thin the paint, and even if I bump up the PSI to clear the blockage.

The only remedy is to strip clean the thing and start again.

I though it must be my dilution, so I switched to vallejo airbrush paints, but even thinned a little I still get the problem.

is this me being rubbish, or the airbrush?

I'd really appreciate some advice. You all talk about it being the best thing ever but to be honest, each time I've tried it drives my up the wall. If I knew a good brush would solve the problem I'd invest, but if it's not the airbrush it seems like a waste of money.

Help!

Rev

 

[airhead]

are you screening your paints to make sure there are not any bits in them?

It only takes a tiny bit between the needle and the cone to cause a blockage. Most Iwatas have a cut-away handle (or the rest of us just remove the handle) so you can reach over and pull the needle all the way back to let the gun flush out the needle/cone. They make commercial screens to filter your paint through, but a piece of panty hose stretched over the paint nozzle will filter the paint as it leaves the bottle.

Cleanliness is paramount. If you've got bits of dried paint in the cup, they are going to end up in your needle/nozzle.

***

You have the air inlet open on that cap? If the paint cannot get air, then it pulls a partial vacuum in the cup and won't come out. (bottom feed guns have this problem more often - paint clogs the air bleed hole.)

***
Not enough pressure? Try running with one or two psi more than you have. You don't want to open up the regulator to the point that you are getting spiders/centipedes.

***
MOST LIKELY:

Tip clog. Look at the tip when this happens. There is paint built up on the exposed part of the needle to the point that more paint cannot get around it. Grow a long fingernail and pick it off. Or, use an off-brand Q-tip - the ones that use the hollow tube between the cotton buds - get it wet and clean the nozzle and exposed needle.
***
Lastly, pull your needle, roll it on a hard surface and look at the tip. Is it bent or does it roll smooth (no up/down motion as it rolls).
A needle with a small bent tip (tip crash or bad storage habits) is a pain to deal with.

***


An airbrush is probably one of the most complex, least user-friendly, un-intuitive tools in an artist's tool kit. Learning to use one involves not only color theory, but paint chemistry and pneumatics. When it is working, it produces beautiful results. When one is not working, it is frustrating.

Do you know any airbrushers in your area? T-shirt guys, cake decorators, fingernail artists? Ask one of them if you can watch or get a lesson or two.

 

[airhead]

You are shutting off the paint before releasing the air? (roll the finger foward to shut off paint - I often leave the air on the whole time.) Don't just release your finger, the needle will slam into the cone.

 

[Rev]

are you screening your paints to make sure there are not any bits in them?

No - I'm using vallejo Airbrush paints so was presuming it wouldn't be an issue. I also add a drop or too of vallejo thinner.

It only takes a tiny bit between the needle and the cone to cause a blockage. Most Iwatas have a cut-away handle (or the rest of us just remove the handle) so you can reach over and pull the needle all the way back to let the gun flush out the needle/cone.

I read somewhere to only pull the needle out through the front of the gun, so as not to get paint in the rear of the airbrush. Do you mean just pull it back like 5mm or further?

Cleanliness is paramount. If you've got bits of dried paint in the cup, they are going to end up in your needle/nozzle.

Dried paint could be the issue, though I'm pretty clean and strip it after eash attempt and often during.

You have the air inlet open on that cap? If the paint cannot get air, then it pulls a partial vacuum in the cup and won't come out. (bottom feed guns have this problem more often - paint clogs the air bleed hole.)

This is a likely suspect and may explain why the stoppages are sudden and why flow sometimes resumes without explanation. I'd thought it was clogging, but this might explain it.

Not enough pressure? Try running with one or two psi more than you have. You don't want to open up the regulator to the point that you are getting spiders/centipedes.

I'm running it at what I understand is quite high - about 20psi so I don't think so. Any lower and I have no luck whatsoever.

MOST LIKELY:

Tip clog. Look at the tip when this happens. There is paint built up on the exposed part of the needle to the point that more paint cannot get around it. Grow a long fingernail and pick it off. Or, use an off-brand Q-tip - the ones that use the hollow tube between the cotton buds - get it wet and clean the nozzle and exposed needle.

Agreed. Can I use the gun without the 'protective' screw on nozzle cap then, I just risk a needle crash right? What I'm hearing is that it's more likely user error than the fault of a cheaper airbrush. This is good to know, as it saves me spending £100 and having the same problem...

Lastly, pull your needle, roll it on a hard surface and look at the tip. Is it bent or does it roll smooth (no up/down motion as it rolls).
A needle with a small bent tip (tip crash or bad storage habits) is a pain to deal with.

I'm fairly certain it's straight. I even bought a spare needle and nozzle after one aborted attempt to see if that was the problem, and even with the new set it occured. So rule that out?

An airbrush is probably one of the most complex, least user-friendly, un-intuitive tools in an artist's tool kit. When it is working, it produces beautiful results. When one is not working, it is frustrating.

Yes, It makes me want to cry - you all seem to be such pros and make it look easy where I'm here swearing like a trooper struggling to get a smooth basecoat. The problem for me is consistency, tonight I managed to get a wraithlord looking beautiful but in the same session completely buggered up some landspeeders - I didn't change a thing!! Not even adding more paint! If I could do it reliably I'd use it all the time, as it stands I never know how it's going to turn out.

Do you know any airbrushers in your area? T-shirt guys, cake decorators, fingernail artists? Ask one of them if you can watch or get a lesson or two.

not that I'm aware of tho there must be a few I guess. Its finding them!

You are shutting off the paint before releasing the air? (roll the finger foward to shut off paint - I often leave the air on the whole time.) Don't just release your finger, the needle will slam into the cone.

Pretty sure I'm not, I normally have that trigger rammed back to make sure the paint is flowing. I don't let it snap off either, at least I don't think so!



I'm in the UK by the way.



Its useful (although frustrating) to know its probably me not the airbrush though.


Perseverance hat on...

Rev





EDIT - this is me:

 

[Tinweasel]

^ What he said

If you're using a bottle feed, is the suction tube set all the way in the lowest part of the bottle to allow for a "vacuum" once the air is on? I've had something like this where the paint fed out for a while (using up the contents of the suction tube) and then abruptly stopped despite there being paint in the bottle.

Are you holding the airbrush properly angled so as to provide a constant feed of paint - same as the first, only will fix itself if you readjust your grip angle?

I'm still coming to grips with mine so this might be way off (only been using it about a month), but maybe your paint is too thinned so it doesn't respond as well to capillary action to get drawn into the airbrush? You probably only want to have it thinned *3 or so. I go with the following ratio: for every one drop of paint, I use 3 drops of non-paint - I'm not an expert, but I seem to be having luck with it so far.

It's probably not related, but depending on what brand of paint you use in it, you might want to adjust the volume of thinner. I get around that problem by mixing in my usual paint thinner ratios (with additives) by paint type in a multi-well palette so it's the consistency I would use if I was brush painting, then add 3* the amount of airbrush thinner (windshield washer fluid, in my case) and then draw the whole lot up with a syringe and deposit the whole lot into the airbrush cup before spraying. I figger it'll behave the same way driven by air as driven by gravity, so if I'm doing a wash, I use the same mixtures prior to adding the airbrush thinner - again, I'm no expert, but I seem to be having luck with it so far.


Oh, and my compressor runs at roughly 60 PSI overall - I bought the "airbrush 'n' compressor" special from Harbor Freight Tools and it works beautifully.

 

[Jericho]

I have an Iwata brush and compressor (HP-CS) and I run my PSI a bit higher than that, more like 30. I have very little actual experience despite owning the thing for 2 years, but the only time it's given me any trouble was when I let my friend use it with his old shitty GW yellow paint. Clog city after a while. The Land Raider Crusader turned out pretty awesome though, maybe a tiny bit too much brushed on edge hilighting (don't blame me I was just there to assist with the airbrushing ) but the airbrushing and weathering techniques I played around with on someone else's tank seemed to work for him

BTW I don't know if this brush has the same lid as mine, but do NOT force the lid on too tight. It's just tapered and friction fit, so if you wedge it on there it'll be a monster pain in the ass to get off again. The tiny hole in the center of the lid should also be clear at all times, so don't overfill your cup or get too crazy on the angles you hold it at, or else it can get clogged up and prevent the paint from flowing properly, just like the guys are saying.

 

[airhead]

I've got a top feed Iwata HP-B. I can run it as low as 5 psi (maybe lower) with well thinned paint and get extremely thin fine lines. A friend thought I was using a new art pencil....

At 20 psi, I'm well back from the subject and painting large areas (fogging). With a wet circle of between 2 and 4 inches across.

I still think this is a gun/technique issue. You either are not doing something right in prep/cleanup or are doing something wrong during painting.

Paint thin like milk. (I can shoot t-shirt paints thick, but I do that at 60-80 psi and am making sure I blow through the fabric).

***
CLEANING: (thorough)
Looking at that gun from the front you have the air cap, then the nozzle. Behind that nozzle is the cone (one or two parts) and the needle.
At the end of a session, you take the nozzle off and remove the cone.
Clean the nozzle under the tap with a q-tip (cotton bud on a stick).
Clean the cone with good flush and GENTLY with an inter-dental brush:

(I suspect that this is your problem - dried paint in the cone.)

Take the handle off.
Release the needle lock.
Pull the needle out the front. (watch your trigger, often the needle is what holds the trigger in the body.)
Clean it with a wet towel or with your fingers under the tap.

Get a set of airbrusher's brushes:

Run the fine one back up the needle channel to where you see it come out the cup.
Use the large one to clean the cup. (reminds me of a baby bottle brush).

Take a sewing pin/old needle/fine wire and clean out the air hole in the cap.

DON'T LOSE ANYTHING DOWN THE SINK.

***
RE-ASSEMBLY:
Slide the needle in from the back. Make sure the trigger is lined up and in proper. Don't tighten the lock nut.

Put the cone on the needle, thread on the nozzle. Some guns need the air cap, some will run fine without it, but you might tattoo yourself.

If you are going to paint, slide the needle up til it fits in the cone. Tighten the needle lock.
If you are done and putting your gun away, pull the needle back a couple mm's and leave the needle lock lose.

***
SHOOTING:
Take that handle off (a cut away handle is worthwhile, but I tend to throw them away.)

Shoot by pushing down on the air first. Then rolling back the trigger until you get the amount of paint you want.
Stop shooting by rolling the trigger foward, then releasing the air. (I teach new painters to hold the air down constantly and just work the trigger).
Adjust line width with the air pressue at the regulator. Low pressure for fine lines and working up close on a hard surface. More pressure for wider lines and more paint.

If you are shooting and it starts spitting, stop and look at the tip.
If there is a paint build up, pick it off with a fingernail. Or a wet q-tip (the cheap ones with the hollow tube). Line the bud up on the needle so the needle will go into the hollow tube. Push down gently and give it a spin. Should have a shiny needle/cap.
If your gun will shoot without the cap, be very careful you don't bend your needle and it is much easier to just pick buildup off of the nozzle/needle with your fingernail. (baby boogers.)

If the tip end is not the problem or it seems to suddenly just stop painting: Point your gun at a trash can, grab that needle lock nut and pull back. This will open the needle up further than the trigger will go and let the cone clear. You may have to do this in a repetitive motion (milking a cow). 2-5 times to get a clog out.

***
Final thoughts:

When you run the brush back up the needle channel. Look and see if any brass or chrome chips come out. Cheaper guns = less quality control and a metal chip up in the needle channel can drive you nuts.

You are using a good paint - I've not used any, but have heard good things. Any paint can go bad. Get too hot or too cold or just old age.
Acrylics are great in that they dry fast. This can be part of your problem. It may be drying in the cone or may be drying little rings/skins in your cup.
If you are in a warm area, try mixing a bit of retarder in with your thinner. It will leave your paint wet longer on the part, but will leave it in the gun longer too.

 

[Rev]

At 20 psi, I'm well back from the subject and painting large areas (fogging). With a wet circle of between 2 and 4 inches across.

Yep - I only use mine for applying base coats or gradual highlights over large areas. Not yet graduated to fine work.

I still think this is a gun/technique issue. You either are not doing something right in prep/cleanup or are doing something wrong during painting.

very helpful to hear, as I was at a loss.

Paint thin like milk.

When I thin to what I consider to be this point the end result ends up with 'blobbing' on the surface. What happens is the paint doesn't adhere to the model and pools in small 1mm or smaller blobs. Is my paint too thin if this is the result?

CLEANING: (thorough)

Clean the cone with good flush and GENTLY with an inter-dental brush:

(I suspect that this is your problem - dried paint in the cone.)

Is an interdental brush smaller than the airbrushers brushes? I have the exact same set as the one pictured (on the key ring) but the smallest one won't clean the screw on cone. The way I've been doing that is with a small sewing needle, but its obviously not working as I'm stil lhaving problems.

All the rest of your cleaning steps I've been doing.

I think the two things that I'm going to try and hope for a big difference are:

1) Using a Q tip mid session to clean the aircap & nozzle (with the needle retracted using the trigger)

and

2) Making sure the holw on the lid is open to prevent vacuum from stopping the flow.

DON'T LOSE ANYTHING DOWN THE SINK.

lol - I dropped the cone yesterday on a carpet took me ages to find it.

RE-ASSEMBLY:

The way you describe it is how I have been doing it.

SHOOTING:
Take that handle off (a cut away handle is worthwhile, but I tend to throw them away.)

Will do this, to enable mid session needle retraction. I presume if I'm pulling it back mid sesh I only pull it back a few more mm than normal? Not pull it all the way back to the trigger?

If you are shooting and it starts spitting, stop and look at the tip.
If there is a paint build up, pick it off with a fingernail. Or a wet q-tip (the cheap ones with the hollow tube). Line the bud up on the needle so the needle will go into the hollow tube. Push down gently and give it a spin. Should have a shiny needle/cap.

This spitting issue happens to me all the time and is the main reason I ruin models with big blobs of paint.

I've discoverd that when I retract the needle with NO airpressure, paint leaks out and pools in the bottom of the aircap (the bit that screws on last in the assembly). When I reapply pressure it all spits out. I think that using the brush WITHOUT the aircap will aid me, if I can avoid crashing the needle.

If the tip end is not the problem or it seems to suddenly just stop painting: Point your gun at a trash can, grab that needle lock nut and pull back. This will open the needle up further than the trigger will go and let the cone clear. You may have to do this in a repetitive motion (milking a cow). 2-5 times to get a clog out.

This is alos a regular issue for me, so will have this technique on standby. only pull the needle back a few mm right? not all the way to the trigger?

When you run the brush back up the needle channel. Look and see if any brass or chrome chips come out. Cheaper guns = less quality control and a metal chip up in the needle channel can drive you nuts.

I hadnlt noticed anything like this, but will remain vigilant.

You are using a good paint

If you are in a warm area, try mixing a bit of retarder in with your thinner. It will leave your paint wet longer on the part, but will leave it in the gun longer too.

Keen to try this, I thought thinner was the same thing. I'm clearly wrong - whats a good retarder to use with GW and vallejo paints?




Thanks so much for your time -

Rev

 

[airhead]

When I thin to what I consider to be this point the end result ends up with 'blobbing' on the surface. What happens is the paint doesn't adhere to the model and pools in small 1mm or smaller blobs. Is my paint too thin if this is the result?

You've got your paint too thin.
Or
You're using the wrong reducer.
Golden, Liquitex, W&N all make an airbrush medium. Mix some of that into your reducer. Something like 1/4 medium vs. 3/4 water. This will add back binder content that the water has diluted away.
Or
You are too close.
Or
Your pressure is wrong.
(start with the first, then try other options)

Is an interdental brush smaller than the airbrushers brushes?

Quite small. Designed to go between your teeth. Find it around dental floss at the druggist.

Originally Posted by airhead
If the tip end is not the problem or it seems to suddenly just stop painting: Point your gun at a trash can, grab that needle lock nut and pull back. This will open the needle up further than the trigger will go and let the cone clear. You may have to do this in a repetitive motion (milking a cow). 2-5 times to get a clog out.

This is alos a regular issue for me, so will have this technique on standby. only pull the needle back a few mm right? not all the way to the trigger?

No, pull it all the way back. Grab the needle lock nut and pull it backwards as far as it will go. Let it go forwards (don't just release it or it will slam the cone). Repeat 3-5 times.

What you are doing is pulling the needle back out of the cone further than the trigger can. Opens up the cone to blow out any clogs.

I've discoverd that when I retract the needle with NO airpressure, paint leaks out and pools in the bottom of the aircap (the bit that screws on last in the assembly). When I reapply pressure it all spits out.

Techinque error. Air first - air last - paint in between. Push down on trigger, then pull back for paint. Roll trigger forward to shut off paint, then release air.

 

[Rev]

Great -

and can you suggest a top line retarder I can get in the UK to slow the dry time down and hopefully reduce nozzle clog?

Rev

 

[Avelorn]

I have had the same issues, very frustrating. Some helpful tips here in this thread that I will try!

I Use the little more expensive version of the same brand (BD-180). I add retarder no, and it helps. But it's also paramount that you put the needle correctly in place. When it closes it should peek out of the hole.

And this is important: Screw off the final part (aircap) of the airbrush so you expose the needle. Honestly, the aircap seem to be ill-constructed. It leaks a tiny bit of water or paint constantly that pools up and splatters away. I don't think it's a technical issue on my part as it does so when I hold a constant stream of paint/water. Without it the brush became useable.

 

[Rev]

Screw off the final part (aircap) of the airbrush so you expose the needle. Honestly, the aircap seem to be ill-constructed. It leaks a tiny bit of water or paint constantly that pools up and splatters away.

yeh this drives me mental.

1) remove aircap

2) remove needle cover at rear for access

3) make sure lid hole is clear

4) add retarder (can someone recommend me a brand?)

four great tips for me to put into place next time. I'm thinking of doing a whack of guardians with a 3 stage of vallejo reds.

Rev

 

[Avelorn]

I've just finished a session today. One thing more, be careful when mixing into the cup so that the thick paint you're adding doesn't fall to the bottom and clogs everything up. Otherwise I had no larger issues this time around.

I use Liquitex "SLOW-DRI" fluid retarder, one drop per 1/4 cup (I don't know if the size of our cups differ though).

 

[Einion]

Acrylic mediums/additives to slow drying that are commonly available in the UK:
W&N Slow Drying Medium;
Daler-Rowney Slow Drying Gel;
Liquitex Slow-Dri;
Golden Acrylic Glazing Liquid;
Golden Retarder;
and also W&N Watercolour Blending Medium (this makes a good painting medium too).

Something to break surface tension - improves flow - could be useful too:
a squirt of dishwashing liquid in your diluting water;
W&N Flow Improver (also slows drying a little bit);
Golden Acrylic Flow Release;
W&N Ox Gall Liquid and Daler-Rowney Ox Gall Solution (don't use if vegetarian).

Golden's Airbrush Transparent Extender might be worth trying too, as a simple one-stop additive for thinning the paints for airbrushing, "possesses excellent spraying properties and is formulated to minimize tip build-up, clogging and surface defects."

Einion

 

[airhead]

I've used liquitex's "Airbrush Meduim" to give more body to an over thinned paint. This has some flow improvers and some binders to help a very reduced paint.

All of the decent artists acrylic paint manufacturers should have a retarder and/or a flow improver. Some have an airbrush medium. The thing to remember is that they are for tube acrylics, so go easy on our already reduced paints. Make about a quarter liter of water (8 oz.), add a drop of dish soap and a few drops of flow improver and/or retarder. If it is warm and a bit more retarder if it is humid cut back a bit on the retarder. I've not got a scientific method, but can tell when I've got it wrong....Also, different brands work differently. Lots of liquitex, just a drop of W&N for similar results.

 

[Drey Foos]

Great -

and can you suggest a top line retarder I can get in the UK to slow the dry time down and hopefully reduce nozzle clog?

Rev

Liquitex slo-dri (It's available just hunt on the web for it a bit) or Winsor & Newton Galleria Drying Retarder (from The Range)

 

[Rev]

Just wanted to follow up on this thread with some results.

So I've been:

1) Using my airbrush

2) Removing the 'lid' of the gravity feed cup and/or making sure the hole is clear.

3) Removing the rear screw on 'casing' of the back of the needle and 'pulling' the needle bakc to clear blockages.

4) Removing the final part the 'aircap' and not using it at all, while trying to avoid a needle crash.



I'm happy to report better progress and results.

The clogging problems are now nearly entirely gone. I think that paint spitting having collected in the aircap was a big problem for me, as clogging in the cup cap causing a stop in the paint flow.

I still get one problem, and that is that on some passes the paint 'pools' in hundreds of little puddles creating an unwanted blotchy effect. I'll try to get pics if it happens again but off the top of your heads what's the cause? I'm using paint direct from a vallejo airbrush dropped, so presume consistency ISNT the issue. Perhaps pressure then? I tried all sorts of pressures and got similar effects. The only thing that seemed to make a difference was the distance from gun to target. What is my optimal distance for miniature work?

Thanks guys - some pics of my latest batch of airbrushed, proof that I listen to your advice!!

Rev

 

[airhead]

I still get one problem, and that is that on some passes the paint 'pools' in hundreds of little puddles creating an unwanted blotchy effect. I'll try to get pics if it happens again but off the top of your heads what's the cause? I'm using paint direct from a vallejo airbrush dropped, so presume consistency ISNT the issue. Perhaps pressure then? I tried all sorts of pressures and got similar effects. The only thing that seemed to make a difference was the distance from gun to target. What is my optimal distance for miniature work?

Your work looks good.

Try painting without the paint cup cap at all, unless you paint pointed up?

As to the puddling, it sounds like it could be one of several things....
1. paint too thick. Don't trust that the bottles are right. Learn to recognize when the paint is too thick or too thin.
2. pressure too low. Low, it starts spitting and not atomizing. Too high and you get centipedes and spiders.
3. painting too far away from the product.
4. orange peel - putting too much paint in one area before the layers are dry.
5. pulling the needle too far back (similar to 4)

 

[thrasymacus]

If it's bubbing/pooling your paint is probably too thin. All the above advice is correct, except a little too complex for a new user.

Even if you're doing everything right, if you continously fire paint through to gun for 3 minutes you'll dry the paint in the nozzle, slowly at first as it builds up (you'll notice your spray is diminshing) until finally you get nothing. Try doing short bursts and lines. About 3 seconds or less each. I've got the same model and that's what finally sorted me out.

I mix my paint in a shot glass and put it in the airbrush with an eyedropper (or take excess out). I use Vallejo and P3's.

 

[Rev]

YES -

I guess I do try to spray in extended bursts.

So its better to spray for shorter blasts, the theory being that fresh paint then sits and lubricates the nozzle? Right?

I'll try all these things on my next sesh and take pictures of any 'blotching' for diagnosis.

Not sure that too thin is the prob, as its direct from vallejo airbrush dropper. Too thick maybe?

Rev