My wife spoiled me and bought me a Badger TC910 (http://badgerairbrush.com/Images/Compressors/compressorcatalog-3.jpg) compressor yesterday and I was playing with it this morning. At first I couldn’t figure out how to regulate the pressure but I sorted it out. I’m still new to this air compressor/air-brushing thing so I have a question.
My question is when I am regulating the pressure, do I regulate to the desired pressure with the air blowing (ie. with the trigger pressed) or with the air stopped? I found that when I had the max. pressure set to 20 psi and I pressed for full air, the pressure on the gauge dropped to 13 psi. I’m guessing that would mean I would be spraying at 13 psi, not twenty, correct? If this is the case, I should regulate with the air flowing so that I know the actual air being delivered with the paint. Right?
Wow, Griffin, this 7 psi pressure drop is even worse than the 5 psi drop of your old Clarke compressor you talked about last month.
Take a look at my post last month on how bad some newer make-in-China pressure regulator is. I expect less than 0.5 psi change but got 3 psi instead. Even that is nowhere as bad as your TC910 regulator.
You either got a defective TC910 or that Badger got a terrible regulator with their compressor. You should contact Badger customer service immediately and let us know what they say.
There is a nice review of this compressor here. Since it has a tank, I would suspect the problem is some sort of restriction in the line from the tank or the regulator itself. 7psi seems too much.
As to which way to set it, my opinion is to set it whichever way works best for your paint/airbrush combo. Absolute psi accuracy is less important than repeatability and regulation.
To answer your question, Yes, adjust the pressure while your spraying since that is the use condition. I also have the Badger TC910 compressor and I get a pressure drop of about 2 PSI when using my Evolution AB (0.2mm nozzle); what size nozzle are you using? That 0-100 PSI gauge is difficult to read accurately in the pressure ranges we use.
You adjust the pressure while pushing down on the trigger. The pressure drop is due to the air flowing through the nozzle and depends upon the size of the tip. Don’t think its a faulty regulator unless the pressure fluctuates while airbrushing.
As an experiment, I hooked up my Paasche F single-action AB. (I have no idea what the specs. are for this brush or how to set anything up on it.)
When I used depressed the button, the pressure dropped 2-3 psi depending on the starting pressure. Less but still significant if I understand correctly.
For all I know, I’m doing something incorrectly. [:(DD]
It is normal for the pressure to drop when the air is flowing from the airbrush. Adjust the pressure regulator while you have the trigger open, before painting.
The amount of pressure drop with flow is an indication of the quality and capacity of the regulator. Any regulator will show a drop from no flow to flow, but 7 psi is a big drop. This seems to indicate your airbrush uses enough air it is near the maximum that regulator can handle.
Still, that is not that big a problem. 13 psi is a tad low for me, but not much. My latest setup runs 15 psi and I am getting a good job on both glosses and flats. Ordinarily I like a bit more for flats, but it seems to work okay.
I always adjust the pressure with the airbrush at rest. It is only a reference point really so it’s not that important which way you do it if you have a compressor with a tank.
A 7 lb drop is not right on a compressor with a tank. My Badger Million Air only drops 1/2 lb. of pressure when the trigger is pressed on the airbrush. Are you sure all your connections are tight and not leaking anywhere?
Spray the connections with a little soapy water and see if bubble appear.
Again, the pressure drop is probably the regulator, not the tank or compressor. You can have the biggest tank and compressor, and if the flow through the airbrush is near the maximum flow rate of the regulator you will experience a big drop.
An analogy is resistance and current flow. If you have a high resistance and flow a high current through it you will get a big voltage drop. Pressure in a pneumatic or hydraulic system is equivalent to voltage drop in an electrical circuit. High flow and high resistance create a big drop in potential. Because airbrushes are low flow devices, the little regulators frequently used in airbrush setups tend to be high resistance devices. You could try a different regulator if your regulator is externally accessible, but it is easier to adjust the thinning of the paint and your working distance and speed of movement of the airbrush than to tinker with different regulators.
If it can be made to work, don’t worry about the pressure drop. My current setup has a much greater drop than my old setup with general purpose compressor and regulator but I was able to adapt and it works fine.
Lots of good comments here! Is 2-3 PSI significant? That asked, it’s easy to obsess over what pressure drop can be expected and I guess the answer is “it depends”! Hook up a spray GUN and you’ll see a real pressure drop. I think the regulators on your and my TC-910 are not the best (nor are those on most small AB compressors from any mfr.) but they work OK! Same for the pressure gauges - I doubt they’re even Class C. My suggestion: Turn your TC-910 on and when it shuts off (tank full and pressurized), depress the trigger on your AB and, while depressing the trigger, turn the regulator knob to adjust the pressure up and down. If you can go from zero to 35-40 PSI, I’d call it done. Use and enjoy the compressor and get on with painting.
While what the two Don (Wheeler and Stauffer) said is true that the absolute pressure value of an airbrush setting is not critically importnat, just a convenience, but it is not true that an accurate measurement in an airbrush system is difficult or expensive. In general, the max pressure and working pressure should be about the same.
We have known how to design good pressure and airflow control equipments for a long time (hundred of years) and we can do it inexpensively today. An airbrush system is a very low pressure and low airflow equipment, which makes the task relatively easy. I am an engineer, but I am not going to bore your with engineering jargons or equations. A good compressor for airbruahing need 3 elements:
You need a powerful enough motor that can generate enough airflow for the airbrush. You don’t need a BIG motor. A 1/8-1/6 horsepower motor that provides 0.7 CFM at 40 psi is plenty for a single airbrush. But the compressor must be rated honestly. With an underpowered motor, the pressure drops off quickly when you start airbrushing. It not only happens with no-name cheap compressor, even the big name company makes underpowered compressor models at the low price end, but they are more honest about it.
The regulator shoudl be a true diaphram type with a small air port connecting the pressure gauge. Some cheap regulator is a simple orifice which provide very coarse control of pressure. Others may try to copy, but completely miss the design of a diaphram regulator. (If you are curious, you can google to find out what a true diaphram regulator is.) For airbrush, a cheap single stage diaphram regulator will be very sufficient and cheap to make. Of course, it needs to be designed correctly.
If the connection to the pressure gauge is a gapping hole, it affects the measurement accuracy. When you remove the gauge from the regulator, you should see a small hole of 3/16" or smaller. The manufacturer can easily cast this into the regulator body instead of leaving a big hole there.
MikeV (greenthumb) mentioned that his Badger MillionAir compressor will drop pressure by 0.5 psi when airbrushing. But you do not need this type of expensive, oil lubricated compressor to get that. I have only a Paasche DA400 compressor with a TCPGlobal true diaphram regulator. They costed me $120 (2008) and $12 (2005) respectively. The pressure never drop more than 0.5 psi with any airbrush I have. If Paasche and TCPGlobal make similar quality equipment today, they should perform the same. The Paasche DA400 or Sparmax TC2000 is typical of today’s mid price range compressors. Not superquiet like the Badger MillionAir or the Silentaire range, but very quiet for indoor use. Best yet, they run cool. The cylinder head of a good oilless compressor should stay cool to the touch after long session of airbrushing. Heat is the worst enemy of these little oilless compressors.
You don’t need to live with a noisy tools compressor to get stable pressure either. Many establshed brand airbrush compressor will do quite well.
I would like people who gets 2-3 psi pressure drop pushing the airbrush trigger to post the brand and model of the compressor they have so that we can compare. The 3 psi or so pressure drop seems to be typical of the pressure regulator from Chinese sources today. There are higher priced airbrush pressure regulators. Will they work better?
Good luck and feel free to share your experience with the rest of us.
Even if they are losing 3-5 psi with a lower quality regulator I say so what?
It makes no difference in the spray pattern of the airbrush at all. If the air is not pulsating as it does with diaphragm compressors then the actual pressure loss when the trigger is depressed is inconsequential.
Set it at 15-20 psi or wherever you prefer, spray some paint, and adjust the gauge to where it sprays the way you like it. Pressure drop doesn’t affect the outcome.
I know, I know! Someone even believe there is no difference between an Iwata and a made-in-China knock-off airbrush.
Quality is something you pay for.
If I get a $80 airbrush compressor at Harbor Freight with the regulator everything, no, I will not be upset if the pressure reading drops a few psi when airbrushing. I just live with it.
If I get the $50 Badger regulator or the $80 Iwata one and the pressure reading is not accurate, I will return the item and demand a refund. I will expect a very smooth and linear action of the adjustment knob too.
Since I paid $12 for my regulator at TCPGlobal and the adjustment is precise and reading stable, I am very happy. I don’t know if TCPGlobal sells the same regulator today. I hope that they do.
Thanks for all the input. I figured the regulator couldn’t be any worse on another compressor so I exchanged the one I bought with another TC910. When I tested this one, I got a 1-2 psi drop when I pressed the trigger. I figure that’s not too bad. As it turns out, I’ll adjust the pressure with air flowing anyway.
Interestingly, the lady at Michaels said that they get a lot of returns on their compressors.
It sounds like that the Chinese supplier of Badger may have a quality control problem. (Yes, I said it may. Not sure how accurate was the Michaels store clerk’s statement about “a lot of” returns.) I sure hope that Badger has a monitoring system in place on their rate of return on these new Chinese compressors.
Some how, I will not be surprised if the Michaels store clerk’s statement about “a lot of” returns turns out to be true. The making of a small oilless compressor requires precision machining and very tight quality control. These processes do not come cheap no matter how low the labor is. Some Chinese factory can do it, but just not cheaply. US retailer wants a cheap Chinese source for higher quality airbrush compressor may find out the hard way when return piles up.
