# Aztek a320 blowing bubbles??



## IanWilkinson (Apr 23, 2010)

Hi all - i use an Aztek A320 airbrush for priming my kits, i use it as my local store has stopped selling rattle can primer - i got the brush new and only owned it a few months, and only used it around 8 times.. Up until today it was working really well!.. infact i wish i had got one sooner for primer on kits.. but today after the top coat of paint was sprayed, the spray stopped and bubbles appear in the side feed cup!!..
i took the nozzle the needle, centre out and cleaned with thinners, then applied a little lube as directed in an aztek forum... but still the thing is blowing back??.. there is a good steady airflow comming from the tip and it appears not to be damaged in any way?... anyone got any ideas?..


----------



## hal9001 (May 28, 2008)

Ian, check to make sure all the fittings are tight. Sounds like your brush is sucking air and sending it back through the cup. I'm not familiar with the Aztec line, but if it has a multipart cap make suer all is tight. That's what it sounds like to me. I have a Paasche that's bad about that and had to put teflon tape around the cap to prevent it. You shouldn't be haveing _that_ problem though with such a new brush.

If it has an o-ring check to make sure it's not compromised. And make sure you've not lost one in cleaning too. But you've got a leak somehwere for sure. Check again and make sure you don't have a clog in any of the areas where air flows.

Hope this was some help.

hal9001-


----------



## dreadnaught726 (Feb 5, 2011)

Check to make sure the nozzel is not clogged. Then check to make sue the nozzel is tight on the body paying particular attention to the small o ring washer. For some reason, Testors has stopped providing this washer with new nozzels. This makes no sense at all. Testors provides a small too to tighten the nozzel but take care not to overtighten it. Also check the psi that you are using. Too high and it could cause leakage or damage. I usually spray between 5-10 psi.


----------



## IanWilkinson (Apr 23, 2010)

thanks for the answers, dreadnaught you spray between 5-10 psi??... i have my compressor on 20?.. as the instructions with the airbrush said to use 20-25 psi?.... i don't have an 'o' ring washer on it either?..wonder if thats the problem!.. will look into why i didn't recieve one..


----------



## falcondesigns (Oct 30, 2002)

I spray at 15psi. mostly all the time,you really don't need more than that,and I use azteks.


----------



## dreadnaught726 (Feb 5, 2011)

I spray closer to 10 psi and find it gives a much smoother action. 10 psi may be too high and could cause leakage. I have e-mailed Testors about the lack of o ring washers about a month ago but they have not responded.


----------



## John P (Sep 1, 1999)

Mine was blowing bubble too last week. I think I got either a bad nozzle, or the paint was clogging the nozzle. I switched nozzles and it worked fine.


----------



## IanWilkinson (Apr 23, 2010)

will order a new nozzel, just cant understand why it would be working fine one moment and just stopped the next?.. there is a steady stream of air comming from the tip as well?.. maybee the needle got bend some how?..


----------



## falcondesigns (Oct 30, 2002)

I have dismantled those nozzles to soak each part in lacquer for years now with no problem,and on occasion the entire brush.The O ring is not necessary.


----------



## irishtrek (Sep 17, 2005)

IanWilkinson said:


> there is a steady stream of air comming from the tip as well?.


I take it that no paint is flowing through the nozzle?? If so have you tried putting your finger tip on the tip of the nozzle and your finger from the other hand over the tiny hole in the siphon cap and then hit the trigger???

Just a thought....


----------



## IanWilkinson (Apr 23, 2010)

tried everything stripped the gun down, the needle, soaked in cleaner, there is a really good airflow comming from the tip - just no paint, as soon as the side pot is connected the bubbles start to appear in the pot??... so to me there is no blockage??... think the bin is calling!!


----------



## hal9001 (May 28, 2008)

Ian, buddy, hate to tell you, but you're on your own! I don't know what else to suggest.

Do you have a schematic? Still sounds like you may have a missing seal/0-ring? That's all I can think of.

The bubbles are a sure sign of the brush sucking air from some where. If you have a removeable tip/cap, try what I suggested with the teflon tape. That's all I've got to offer.

Best of luck!

hal9001-


----------



## dreadnaught726 (Feb 5, 2011)

Check to make sure the needle is moving smoothly. Sometimes it gets stuck in the white sleeve. A gentle flick on the white end is all that is needed


----------



## IanWilkinson (Apr 23, 2010)

many thanks, ive opened up the body of the brush and cleaned all internal parts, the needle tip is moving very freely.. when i press the top trigger the needle is moving no problem.. air is flowing out.. but still no paint!.. ive even tried water on its own!... nothing??... just bubbles, this is just plain wierd!


----------



## rkoenn (Dec 18, 2007)

I've never disassembled an Aztec but from my experience with my Iwata and Badger if you are getting bubbling in the cup it means that air is reverse flowing from the nozzle back up the cup. When using my airbrushes when that happens it means the nozzle is clogged and so the air trying to get out the nozzle is blocked and backs up coming out the cup. For mine usually I just swab the needle tip with a brush moistened with paint remover to clean the dried up paint off the needle. Now with yours that is not the case and my biggest suspicion is that your nozzle is clogged. I have cleaned my nozzles, or thought I had cleaned them by soaking them in paint remover, only to find after I tried using them that they were still clogged. Lately when cleaning a nozzle I soak it, scrub the inside with one of those small q-tip like brushes, and then finally I very carefully "ream" out the inside of the nozzle with the needle. I frequently find when doing that that old dried up paint comes out the tip. You want to do it carefully to prevent damage to the nozzle or the needle. Acrylic paints really magnify this problem as they will dry hard inside the nozzle and you can't see that it is clogged so you just have to do this blindly. My latest problem is with my really fine tipped Badger Renegade. The nozzle is extremely small in outlet diameter as well as physically. You could lose it in a second. However lately I cannot get good airflow from the brush. I believe it is a trigger problem that it is not depressing the valve far enough. I am taking it to Wonderfest to show it to the Badger guys.


----------



## dreadnaught726 (Feb 5, 2011)

Are you using a color cup or bottle? If you are using a bottle, make sure the little hole on the top is not clogged and if so clean it out. If clogged this would definately prevent paint flow. Also, not a good idea to open up the Aztec body. There is no need for it. Unlike Badgers and other internal mix airbrushes, the paint mixes in the nozzel and never enters the airbrush body. The only cleaning which may be needed is where the nozzle screws into the body and Testors provides a tool for this.


----------



## IanWilkinson (Apr 23, 2010)

Dreadnaught726 i took the body apart as there is an aztek forum that said to do that as a last resort, as sometimes paint can backflow into the inside.. so i opened it up and cleaned all the inside, but to tell the truth it was very clean inside.. so its now been retired.. i tried everything i could think of and everyones sugestions on here and another airbrush forum.. and nothing seemed to work?... my other dual airbrush works no problem, but its a traditional brush... not a plastic nozzle Testors type... the only other thing i might have been able to do is to send it to be looked at by a proffesional..


----------



## dreadnaught726 (Feb 5, 2011)

I am sorry to hear you have had no luck solving this proble. It is a shame you took the body apart since Testors has a lifetime gaurantee on the body and will replace it free. Very rarely does paint backwash into the body and I am sure your poblem is with the nozzel. Since taking the body apart you probably voided the warranty. You could try sending it back to Testors and see what happens. You never know. One question, does this problem occur with different nozzles? When it bubbles up, is there air coming out of the front of the nozzel? If there is, than your problem may be a clog or defective nozzle. I have had some defective nozzles on occassion.


----------



## irishtrek (Sep 17, 2005)

IanWilkinson said:


> will order a new nozzel, just cant understand why it would be working fine one moment and just stopped the next?.. there is a steady stream of air comming from the tip as well?.. maybee the needle got bend some how?..



those nozzles from Testors can be taken apart cleaned and put back together, I know because I do just that when I clean mine after painting. also what type of paint are you running through your airbrush???


----------



## dreadnaught726 (Feb 5, 2011)

I always take the nozzles apart before I clean/store them in lacquer thinner.


----------



## IanWilkinson (Apr 23, 2010)

there is a good steady flow of air through the tip where the needle end is pointing through.. i have soaked the three seperate needle parts in cellulose thinners and they are all spotless, the paint and thinner im using is Vallejo - but even plain old water wont go through the plastic tip??... i have even tried to remover the needle and put just the two assembled parts into the airbrush.. still nothing comming out of the end??.. so that is telling me there is something wrong with the way it picks the paint up.. but looking into the end with a flash ligh it is also spotless and clean?.... i didn't know about the lifetime warrenty on the brush.. dam!..lol


----------



## dreadnaught726 (Feb 5, 2011)

I have had similar problems airbrushing Vallejo. Proper thinning of this paint is key. Try spraying a different paint brand like Testors (if available in UK) Or better yet, just use plain water and spray different patterns on a piece of brown cardboard. If you are getting patterns on the cardboard then in all liklihood it is the paint consistancy or pigments that is clogging the tip


----------



## irishtrek (Sep 17, 2005)

Back when this problem first popped up and after you soaked everything did you take say a very thin piece of wire and stick it through the nozzle pieces after it had been taken apart??


----------



## IanWilkinson (Apr 23, 2010)

water aint even getting drawn into the airbrush, just bubbles - irishtrek, not wire - but i made sure it was clean and it looks brand new since its been socked in thinners.. the needle can be seen drawn in and out of the tip when the air button is pressed?... im now resigned to the fact it's goosed.. i ordered a cheap brush from ebay the other day - all im using it for is primer use.. so the testors has totaly bit the dust!


----------



## dreadnaught726 (Feb 5, 2011)

That is really strange. I have been using the Aztec airbrush for 16 years and have never encountered these problems. I am really at a loss as to what else to suggest. The only time I ever had any bubbling is if the needle got stuck or I overtightened the nozzle. I'm really sorry that you cant use this airbrush because it really is excellent when working. Since you are not going to use the airbrush anyway, try sending it back to Testors and see if they will honor the lifetime warranty.


----------



## irishtrek (Sep 17, 2005)

The airbubles may also be a result of the nozzle not being screwed in tight enough, I know because it has happened to me a few times.


----------



## dreadnaught726 (Feb 5, 2011)

Have you tries using a different tip?


----------



## IanWilkinson (Apr 23, 2010)

yes ive tried a different tip and the same thing?.. thats why i thought the part that sucks the paint through must be damaged somehow?.. but for the life of me i cant look into it - to see how it works?... it must be a ventury or capillary action that sucks the paint through?.. any one got any ideas how it works?.. or even some type od basic diogram?


----------



## dreadnaught726 (Feb 5, 2011)

As the air comes out of the body it blows across the paint intake creating a vacume across the inlet which sucks the paint into the nozzle. Try this, take the tip off and attach a bottle/cup of water to the inlet and press the trigger. You should get a mixture of air and water coming out of the end. If not, then there is definately something wrong with the airbrush body. If that's the case then you may be able to have the airbrush replaced under warranty. Please let me know how you make out with this test.


----------

