Lint? Sludge? Other?

Chili

do you have a name & source for the "fine metal mesh filters bought at an industrial supply place"?

Pipe screens at oatwillies.com.

do you have a name & source for the "fine metal mesh filters bought at an industrial supply place"?

Say Don, thanks  for the tip. This expaains how dust always finds a way to get on my models during painting. That makes total sense. 

When liquid flows through a nozzle, it can pick up a charge.  As a result it can put a charge on the model.  This attracts dust.  This worse in very dry weather- moisture bleeds off  the charge rapidly. I have friends who spray their workshop/painting area with a spray bottle of water to put more humidity in the air to reduce this effect.

Looks like you probably sorted this out, Steve. Looks like BlackRook nailed it for you.

That's a rather severe bit of tip damage, I'd think. Hope the new needle does the trick for you.

Hello everyone.  I want to take a moment to close the loop on this.  With your help, a lot of help from Patrick, and some perseverance, the problem was identified. 

You will see the problem in the image below. It was an eureka moment when I first discovered the defect.  You can see a burr at the very tip.

I bought this AB in October of this year.  When I first opened the package, I recall feeling a rough spot on the tip of the needle.  I thought that this was odd, but I had to set it aside to investigate later.  I got very busy with things and I completely forgot about this when I first started using the brush several weeks later. Tough to get older. So it is my belief that the needle was defective at the start.

I have a new needle on order.  I look forward to trying this brush with a good needle.

Thanks for your help.

Steve

It sounds like a mechanical issue, such as a damaged tip (since you've checked the needle)?  Get a magnifying glass and examine your AB tip for a bend, a piece of lint stuck in it, etc.  I once had a tiny fiber from a paper towel stuck in the tip of the AB and it cause this sort of issue.  The paint would collect on that fiber and spatter every few seconds.  But since you've checked that, the only item left is dirty paint.  Try to get a screen filter, silk filter or the like.  Maybe a brand new paint bottle to see if it still happens.

Oh one other thing.  I was not starting and stopping the brush while positioned over the spoon. I have done this long enough to know you don't do that. The splatters occured during a maintained paint output.

Greetings again Patrick..  I will take Modelmakers thoughts into consideration.  However... When the problems occurred I tried various thnning ratios and airpressures, it did not seem to make a bit of difference.   Also.. when I noticed the splatter occurring, I immediately checked the needle tip and It looked fine. I did not see any paint build up on the tip.  In fact...this AB is the cleanest working one I have used thus far.  This AB is a new model for me so maybe you won't see build up? Not sure. I had a Badger 200 previously and whenever splatter would occur for me it was the result of paint buildup on the tip. In those cases I fixed the problem either with more air pressure or more thinner.  Sometimes I did both.  That is the vexing thing. With this AB, the problem is not behaving like anything I have ever seen before.

A compatibility issue is another thought I considered.  I thought if there happened to be some acrylic in the PC or AB, perhaps the enamel thinner loosend it and the mismatch of thinner congealed it. Just one other thought along this line of thinking. The enamel thinner I am using is about 20 years old.  The bottle was never opened until recently.  I wouldn't think that enamel thinner could go bad but...maybe?  To play it safe I will pick up a new bottle today.

I dismantled my AB last night and it actually looked pretty good inside.  I don't have an interdental brush so I will pick one up today.  Then to be sure I will go back and clean those passageways and such with laquere thinner. I will also try and locate some paint strainers. If all goes well, I will try another test spray today.

Thanks again for everyone's help.  I will let you know how this works out.

Steve

P.S. I forgot, I spray typically between 12 psi for low, up to 20 for high. It's just a matter of sight checking and adjusting until correct.

Good lighting on the subject is another important issue, you can't really determine much if you can 't "read" the paint as it flows on. Light is so useful, for avoiding going too dry and getting a rough surface, or too wet and getting runs.

Patrick

That's an excellent point from Modelmaker, at various times I have seen modelers have similar results. I have no idea what caused all of the complaints, but in one instance it was thought that a compatibility issue between thinner and paint was the culprit, of course not in your case, your products were definitely on friendly terms. But the results of one instance looked much like yours.

Paint can definitely cause little flecks like that, if the paint does not leave the AB at an appropriate pressure or viscosity. For reference, while my pressure settings are rather all over the board depending on the type, in general I start at about 12 psi, check my spray distribution, (pattern,) then adjust as I need. Keeping scrap material for testing is ideal, but it should be shiny and not absorptive, or you won't get an accurate feel for the spray quality.

For thinning enamel I start at 3:1 paint to thinner, but usually add more in steps while testing. Lacquer same, acrylic depends on makers instructions. But in general I do thin quite a lot.

I think once you get some fresh paint, then give the AB a good bath, mix some paint carefully, the problem won't return. I hope it works great for you next time. Do let us know.

Patrick

It looks like splatter from having the pressure too low and the paint to thick. It is paint, not debris. it is paint flicking from the needle. Paint needs to be thin and you do not begin painting pointed at the model or spoon, you begin off the subject and move over it, ending past it. It is splatter.

Hi Patrick.. the information that you provided me is awesome. I am going to print this and keep it handy. Based on your process outlined, I see where I have failed with many things. There is too much to comment on but I will make a few points.

I have been using paper towel to clean the AB cup port. This is some really cheap bargain towel, and I think this stuff has more lint than most. I would not be surprised if that is the major cause of my problem and...that my AB needs a thorough cleaning. My AB cleanings consisted of running thinners through, pull the needle, clean it, and clean the AB cup port. I have not disassebled the brush completely. Frankly, I was in error thinking I didnt need to. Like what you mentioned, it is often said that a good flushing will do the job. That is what I drew my process from. From my experiences now, I agree with you that it does not.

I had an experience today that proves this out. Today I sprayed some acrylic. When I was done, I added acrylic thinner into the cup, and I sprayed it through. Well guess what. There was still dried on Acrylic around the cup walls that I could not remove even with a paper towel and elbo grease. Even after running the thinner through, it stayed on. Now I can imagine what is stuck on inside of the brush. So then I added the much touted windex window cleaner to the cup. That did nothing to remove the dried paint either. Then I went to lacquer thinner and ran that through the AB. That did it, but even with lacquer thinner I had to work that paint off some. Acrylic paint is serious stuff. From now on, and after spraying acrylics through, I am going stright to lacquer thinner. BTW...I ran all those thinners through and when I put a swab into
the cup port, there was a bunch of paint still in three too. It's crazy. Bottom line...running thinners through is not enough.

Next step is to tear down my brush.

Thanks again Patrick!

Steve

PS...I was having trouble getting this message to post.  So I copied the text that I wrote and pasted it back in.  Usually when I have do that, I lose all the indents.  So I apologize if it appears as one big paragraph. 

Hi, Steve - Now with that photo, I can see that the particles are actually in/under the paint surface. By the way, it was a very good decision to test on such as the spoon, rather than a model.

First your question about filtering, I filter when pouring mixed paint in the AB cup. But there are several prior steps to consider.  

1) Paint in the bottle. That is usually dependably in good condition when freshly opened, but solids will have settled. At first use I always give it a thorough stir, making sure the stick moves completely around the bottom, gathering up all of the settled solids. That will appear as a ball of gunk at the bottom of the stick, continue stirring until that wad has been blended with the rest of the bottles ingredients, and is a consistently smooth liquid. Then I use a Badger stirring blender, (any will work that can fit in the bottle.) That may sound like overkill, but it really does make for an even more thorough blending of the paint, well worth the time.

2) I absolutely NEVER shake it to mix, at any point in the life of the bottle. That only makes for a messy cap interior and bottle threads, plus paint on the insides of the bottle dry and can result in flakey bits that get stirred into the paint at next use. That would be a time when filtering of the paint from the bottle would be needed, but as you said, it's pretty thick stuff and I think a good bit would be wasted. Stirring is the better way for me to prepare the paint for use.

3) I don't pour the stirred paint out of the bottle, I use pipettes for drawing it out of the bottle, for blending with thinners and additional agents. That keeps the bottle and remaining paint in like new shape, for continued use.

4) Prior to adding paint to the AB cup, I always run at least one full cup of the SAME thinner added to the paint through the AB at high pressure, 30 psi or more if possible, two rinses even better.

5) Ensuring the filter I'll use is clear of any foreign material, then I add the spray ready paint to the AB cup.

After use AB cleaning, (in my opinion,) involves much more than a simple spray rinse of the brush. Any dried paint residue left behind in the AB can break loose at next use, then contaminate the spray mixture as it leaves the AB.

When through spraying I run a thinner rinse batch through the cup and AB, remove the cup then swab it out with Q-tips and thinner. Then I invert the AB, (nozzle end facing down,) pipette thinner into the cup intake port, then press the trigger and spray that through the brush, repeated a few times. By then the AB is FAIRLY well cleaned, but not completely..  

I have a 155 Anthem among several others, and can describe some of the interior spots that do require physical cleaning with implements. like cotton swabs, interdental brushes, even toothpicks enter into my regimen. First is the 155's cup intake port, that needs a good swabbing with a cotton bud soaked with appropriate thinner. I insert the swab, then pipette some thinner into it, swirl it around and keep at it until the port is fully clean.

With the AB disassembled I use an interdental brush, enter the front of the body, then pipette thinner into the intake port, (still facing down.) Run the interdental brush around, back and forth, that will agitate paint residue and put it in solution with the thinner, repeat as required, now the body is clean.

Cleaning of the spray nozzle, head and needle is straight forward, easy to see what needs cleaning and how to get to it. So, the contaminates you see in your test sprays, could come from several sources, paint bottle, airbrush residue, cleaning equipment, etc. For that reason I avoid using paper towels, but there are lint free towels available at a still affordable cost.

I hope you get the situation resolved, likely it's something rather simple causing it, best of luck with it. The first place to start would be a thorough cleaning of the AB, then try some fresh paint. I always remind myself that foreign bits come from several different sources, I try to eliminate them by methodical steps along the way. I get P.O.'d easily when I do screw something up, (and knew better.)

Patrick

Hello Chrisk-

Those dings are the paint splatter or particulate matter I am questioning.  The spoons I painted are glass smooth and no dings.  Here is a photo that gives a wider view.  This might help to make sense of things.

Steve

See all those what look like dings?  That came out of the air brush.

Hey Patrick.. Thanks for the reply.  These test sprays were done on plastic spoons.  Those are very smooth and so the bumps that you see are all paint.  Being that they are plastic spoons, I didn't ruin anything. I have an TBM Avenger waiting to be painted and I wanted to test things on spare plastic first.  Good thing that I did. 

I do believe the particles are in the paint.  Especially with the last photo.  That splatter happened all at once and I had seen it happen. With the first photo I had seen the splatters appear as well.  There is something going on from the paint and through the brush.  I would expect that to happen if the tip was getting gunked up but that was not the case. I suspect the paint has gunky pieces or, I am not cleaning the brush correctly leaving stuff behind that gets released through the brush later.

I am glad to hear you mention filtering the paint.  I don't do that, and I was considering that. Until now, this may be the first I had seen or heard anyone say to do that for hobby paint.  Everyone seems to dump the paint straight in from the bottle. It makes total sense to do.

Question for you.  Hobby paint is pretty thick straight from the bottle.  Do I filter the paint straight from the bottle or should I pour some into a jar, thin it, then filter it?

Thanks again.

Steve

In the 1st photo, it almost looks like the surface itself has tiny dings and nicks.  Can you post better photos?

Bakster - That's a tough one to evaluate in photo's, I can't really tell if it's IN the paint surface, or ON it. If it is paper towel particles, they should have been able to be removed from the AB with a good spray rinse when cleaning was finished, and once more before loading paint into the cup.  

Just to satisfy your own concerns, maybe try spraying the same mixture on something smooth and check again. If the same results happen, ditch the paint AND thinner, replace with fresh. Also, it's a good practice to filter your paint when adding to cup.

I use tiny ones that I buy at an industrial supply place, I think they may be commonly used by lab's. Disposable fine metal mesh surface, just a few bucks for 100 count. More than once I've been surprised by how much crud they did remove.

Hope you can salvage the job by careful sanding and re spray. Welcome back from your time away.

Patrick