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Air brush problems


henryhatch

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I've re entered modeling after many years absence. I airbrushed my first model with primer and am having a number of problems with my airbrush. It spits at the beginning of a line after being used for a short time. Also the brush leaks unless the nozzle is very tight. If tightened too much when I press the trigger nothing comes out of the nozzle and the top of the paint cup blows off. I tried cleaning everything I could with lacquer thinner, and have tried thinning with water and isopropyl up to 50% using acrylic paint. Should I try Testors airbrush thinner ?

 

I have a Testors model master brush which is probably at least 20 years old. The brush is not supposed to be taken apart so all I can clean is the nozzle, port, and paint cup. I should also add that I am using a co2 tank to run the brush. It has a single stage low pressure regulator with a working pressure of 50 lbs and is not adjustable.

 

Is it time for a new nozzle or airbrush or is the co2 tank a problem ?

 

 

Henry

Edited by henryhatch
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Model Master, I'm not that familiar with the 'brush, but I'm guessing it is similar to the Aztek.

 

First, I think 50 lbs of pressure is way too much...I would suggest a regulator that can adjust down to 10 lbs or less. Can't remember the recommended pressure (I had an Aztek and used it for two years) but I think it's 20-25 lbs maximum. I usually used 10-15 lbs with mine.

 

The spitting could be from tip dry...acrylic paint drying on the needle or in the tip. An acrylic retarder added to the paint might help.

 

Lacquer thinner is way too strong to clean this particular airbrush, as it will ruin the seals. Sadly, I'm speaking from experience here...

 

I switched to a more traditional airbrush, and never looked back. Actually, I did go back and try the Aztek with acrylics, but found I just didn't like it anymore.

 

On a new airbrush, buy the best that you can afford...Badger, Paasche, and Iwata all make good airbrushes. I've used all of them at one time or another. I recently got a Peak C-3 from Bearair.com (general purpose, gravity fed) and have really liked it...inexpensive and it works very well. Also, I use my Badger 155 Anthem on some aspect of almost every project (general purpose, siphon fed).

 

There are others on the forum that will have good advice for you...

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If you are looking at a new airbrush, look at the Badger Velocity. Awesome brush. If you are just getting back and want to get a new brush cheap, look at a Badger 200, it is single action and has less of a learning curve than a double action brush.

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As has been mentioned, you will want to drop the pressure--50psi is a bit high. Also, invest in a new tip--sounds like the one you have is blocked. You can (although Testor's doesn't recommend it) disassemble the tip and clean it. Be careful not to split the actual tip orifice.

 

That should get you going again.

 

If you want to go new, I'll concur on looking at Badger--I've been using Badger products since 1978 and they haven't let me down. I like them so much, in fact, that I just ordered a new Badger 105 Patriot on Friday....

 

Ralph

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With splatter it could also be too much pressure or moisture build up at the tank. I swear by the pressure regulator/moisture trap I now have.

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Dittos on the Badger 200 single-action. Have been using this one since 1973 and love it's simplicity.

 

Likewise, the air pressure: I use a regulator on a pressure tank, set to deliver about 10-12 psi. If you get intermittent spattering and if your paint is thin enough that it's not causing clogs, maybe look at that paint cup/lid: There should be a vent hole to allow air in, as the paint leaves. That hole can clog and create intermittent pressure relief issues as you use the paint. If any seals are damaged inside the airbrush, that can also create spattering & pressure regulation issues (in the Badger 200 it's a little TEFLON ring).

 

Don't give up. Break out an expendable paint-hulk practice model and play with the airbrush. Try everything. You won't break it.

 

My biggest learning points so far, have been:

1 - Thin the paint more than I really think I want to. Performance can vary with fineness of pigments in various colors, paint brands and such.

2 - Clean the airbrush obsessively, between colors, etc, etc. I flush it with a generic, enamel-friendly paint thinner out of the can from ACE Hardware. Sometimes, it's good to just take the airbrush apart and let (the metal parts) soak in a jar of the stuff overnight, or longer. The more expensive, so-called "airbrush thinner" I use only for thinning the paint. The much hotter Lacquer thinner is reserved for cleaning jobs where serious crud has accumulated.

 

 

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A moisture trap is not necessary for a CO2 tank but a regulator is. I have been using a CO2 tank now for about 10yrs. I have four Paasche airbrushes and am very happy with them.

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I have heard that CO2 gives off moisture at some point. This has not been my experience though. I suggest that you buy a two stage regulator. Mine has a guage showing tank pressure on the first guage and regulated pressure on the second. I rarely measure ratios in my paints, but rather just eyeball it to the point where it (the paint/thinner mix) is the consistency of milk. I guage this by its ability to run back down the inside of the bottle leaving only a thin translucent film to remain. It takes a little learning but does the job for me. 10 to 20 psi is my usual working range

 

I have also discovered that all acrylics do not thin with the same thinners. I have had some brands curdle using alcohol and others doing the same for water. I like the Tamiyas for the most part. It thins with alcohol and clean up is a snap, including stripping to redo a botched job. Windex is perfect for clean up. I have heard amonia works too, and Windex has amonia but it sure smells better. In my area Tamiya is much more prevalent that the Lifecolors, Gunze, Mr. Color, etc.

 

I switched to acrylics due to the lack of aerosoling odors that come with lacquers and enamels. My model build area is now colocated with the rest of our home and the vapors are too too much for colocating in an interior.

 

If you think you may have a sealing problem try using a tiny amount of beeswax on the threads of any removable parts. This will seal and is neutral to the parts and paint contact. Another thing you could use is glycerine. A tiny drop on the threads of any mating parts will give a nice seal and does not leave a hard to remove residue loike beeswax.

 

Check the cone that the needle projects through. I had a cracked exit annulus once due to a misadjusted needle which force itself past the normal seating.

 

 

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Thanks for all the useful info. I think I will probably purchase a new airbrush. Cleaning my old testors with lacquer thinner may have killed it. I will look at the Badger 200 single action as suggested here.

 

I have a question on purchasing a regulator. Is there a standard connector available that will allow me to connect the airbrush line to the regulator ?

 

Henry

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Henry,

If lacquer thinner is used to clean the brush it is advisable, so I'm told, to be sure to remove any rubber gaskets from the gun, and there may be several at various places in yours. It might be as simple as replacing them. That problem can sometimes be evident. If you are getting bubbling out of some joints where parts are screwed together, look there for a gasket.

 

I also think you will need to get an "air" source with a regulator. I use a big 'ol Husky compressor, with a regulator that I bought in a pawn shop. I also have a bottle of nitrogen, with a regulator. Nit is an excellent propellent. No moisture condensation, no noise due to a motor cranking away, and a small bottle (about two feet tall by six inches in diameter) lasts about a year for me.

 

 

 

 

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Thanks for all the useful info. I think I will probably purchase a new airbrush. Cleaning my old testors with lacquer thinner may have killed it. I will look at the Badger 200 single action as suggested here.

 

I have a question on purchasing a regulator. Is there a standard connector available that will allow me to connect the airbrush line to the regulator ?

 

Henry

 

I doubt that the lacquer thinner "killed" the Model Master airbrush--I used to clean mine with Floquil's Dio-Sol (back when the paints contained Xylene) and never had an issue. As someone who used (and liked) the Model Master, the fact that sooner or later the body would leak paint and the fact that I was replacing nozzles frequently made me return to my Badger 200 and 150. Both are fine tools that will last a lifetime. The Aztek (nee Model Master) started out as a fantastic tool, but it got that it required trips back to the factory for repair. When the warranty was lifetime on the Aztek, fine--but now it is a 3-year warranty....

 

Most regulators either come with no fitting or a basic 1/4" NPT male-male nipple. Badger's hose connectors (like most airbrushes) is a proprietary fitting, but they do make an adapter that will work. It is Badger P/N 50-023.

 

Something else you might want to consider is a braided hose. Badgers usually come standard with a vinyl hose that doesn't really work that well with a compressor--it may do fine with the gas bottle, though....

 

And, last, a link:

 

http://www.badgerairbrush.com/PDF/airbrush101printfinal.pdf

 

Actually, Badger's site is full of great info. Check it out, including the "Garage Sale" link. From time to time, they have great deals on airbrushes that are either surplus or cosmetically damaged. It is PayPal only, though, so if you don't do PayPal....

 

Cheers!

 

Ralph

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Thanks for all the useful info. I think I will probably purchase a new airbrush. Cleaning my old testors with lacquer thinner may have killed it. I will look at the Badger 200 single action as suggested here.

 

I have a question on purchasing a regulator. Is there a standard connector available that will allow me to connect the airbrush line to the regulator ?

 

Henry

 

A welding supply store will have the regulator and also tank if you need one. Refills are cheap because you just do a tank exchange. Empty one for a refilled one. You only pay for the gas. If the welding supply house does not have an adapter just go to an auto supply store. They have bins of brass fittings and I always find what I need. P.S. don't go to a chain store but rather a well supplied local guy. The chains may not have a supply of fittings due to standard inventories.

 

I like syphon feed brushes and single action. Reason for that is that I tend to get too enthusiastic and spill out of the gravity cups. Single action is easier for me to control due to arthritis and carpal thingies. I use Iwata and Grex. Both are double action, but they have the capability to be preset and that essentially makes them good for me.

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I have been told that your gauge (the second one) you're going to adjust the pressure on the air brush should have a range that the needle is mid range when shooting. Example: If you shoot at 10-20 psi, you would want a gauge that the maximum pressure is 30 or 40 lbs. I rarely run above 10 pounds, so I have a 25 lb gauge.

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I bought my CO2 tank and regulator from a welding supply shop. When i went there I took my air hose from airbrush with me and fitted and adaptor for it at no extra cost. The whole setup cost me about $270 and a refill for the tank when I do an exchange is $8.00.

When i thin my paints I also do not measure but it by letting it run down side. You should never add thinner to the paint in the bottle it comes in as it can sometimes cause it to go bad. I mix mine in a shot glass as it is easier to clean because of the courved bottom and never put unsed paint you have thinned paint back into bottle.

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I have been told that your gauge (the second one) you're going to adjust the pressure on the air brush should have a range that the needle is mid range when shooting. Example: If you shoot at 10-20 psi, you would want a gauge that the maximum pressure is 30 or 40 lbs. I rarely run above 10 pounds, so I have a 25 lb gauge.

 

My guage goes from 0 to 60 lbs. Yours will give better accuracy.

 

The 2nd best rule is "Whatever works for you." The first best rule is to do whatever your wife says.

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My first airbrush was a Iwata Double Action. I was advised to buy the best airbrush I could afford and I am glad I did. The double action required more of a learning curve (so I am told, I wouldn't know since I never used a single action) but my modeling results improved almost immediately. Being all metal, I flush with acetone. I have been doing this for over a year with no negative results to my airbrush. If you have a hobbly lobby in your area, you can use the 40% off coupon they occasionally put online and save quite a bit of money. Bubbles in you cup or bottle indicate that you do not have a good seal on the painting end of your brush. It takes pressure to push paint through the orifice so if you do not have a good seat, air blows back into your cup. Spitting paint is usually caused by several different factors:

1. Paint is to thick. Should be the consistency of skim milk. A good test is to take a toothpick and dip it in the paint and drag it up the side of the mixing cup. If the paint does not run off the toothpick and down the side of the bottle, it is probably to thick.

2. Paint is drying in the nozzle or on the needle. (with the pressures you are spraying with and if you use acrylics, this would be my guess)

3. Paint has dried gunk in it (You know, stuff that falls out of the threads, dried paint from the lid or the sides) plugging your nozzle.

I have had trouble with all three. Part of the learning curve. The first just takes alittle practice. The second is easily fixed by either getting a compressor with a regulator or purchasing a regulator. I spray between 10 psi and 20 psi depending what I am doing. The third is also easy to fix. I wipe down the lip of the bottle every time I open it, I use a disposable eye dropper to transfer paint from the bottle to the airbrush taking care to only get paint from center of bottle, and I never shake my bottles. I bought a electric paint stirrer from Squadron and I love it. I hope this helps.

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I think Coast airbrush http://www.coastairbrush.com/ has the largest supply of all things airbrush. They have been around for quite a while and give great service. If you are going to use lacquers or lacquer thinner, they will replace the needle seat in any brush they sell you with a teflon seal that is impervious to most solvents. If you are ever in Southern California, there shop is a stones throw from Disneyland. Kind of a Disneyland for painters. Worth your time to go.

 

 

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