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How to Tune in Your HVLP Spray Gun- With Kevin Tetz

If you have never painted with a spray gun before, or if you have only recently converted over to spraying with modern high volume low pressure equipment, there are new things to learn. Here is a little primer Kevin Tetz did recently for us explaining which knob controls what function, and how to set your gun up before painting. The gun he uses in the demo is the Eastwood Concours HVLP paint spray gun (item #51550), but the controls are typical of most HVLP guns these days.

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The first thing you should do after unpacking a new spray gun is to clear in thoroughly. The guns are packaged and shipped from the factory with protective oils and chemicals coating the insides of them so they can sit on a shelf in a warehouse for months without fear of corrosion. Run solvent through it like you would after painting with it. The Eastwood Aerosol Injected Cleaner (item #12846) is a spray can solvent complete with long thin nozzle specifically for clearing out tiny passages like those in spray guns.

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This lower, larger knob on the back of the gun is the Fluid Control

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The smaller knob above it is the Fan Control

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And the knob on the bottom, which some guns don’t have, is the Air Control.

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Now let’s put some paint in it and take it for a test spray. The first shot immediately tells us that the gun is not set up properly. The spray pattern is a concentrated spot of paint like a bull’s-eye.

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The first thing to address is the fan control, opening it up for a larger size spray pattern. The best thing to do is turn it all the way out, then work in to fine tune it.

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Now we get a fan pattern that is really wide, but splattered, and without a lot of paint in it.

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So now we open up the fluid control knob all the way and really flow a lot of fluid through the nozzle

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Now you get a nice, fat, wide, wet fan spray pattern with the correct football or elliptical shape. The tapered edges make it easy to lay down your overlap and get perfect coverage without tiger striping.

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It may help to think of the spray gun like a carburetor and the adjustments like changing the jetting, throttle opening, float level/fuel pressure, etc. The goal is to get the right amount of paint and air coming out of the end of the gun, with the right atomization to flow out properly.

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Another important consideration is air pressure. This gun requires 25-30psi at the inlet. That is important to know, because you have no way to measure it at the air cap. You can install a regulator at the end of the gun, but it may be awkward to paint with it there. The best thing to do is install the gauge at the gun, set the pressure at the far end of the hose to give you what you want at the gun, then remove the gauge to make the gun more maneuverable.

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The air cap pressure is typically 1/2 what the inlet pressure is. And remember, the inlet pressure is properly measured with the trigger of the gun pulled in (and the fluid flow all the way closed).

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And that should give you a good baseline to start spraying test panels with. Of course you want to practice on things that aren’t important before you attempt to paint your car. A good way to practice, without the need for elaborate safety gear, is to paint sheets of cardboard with water based craft paints that are non-toxic. This will allow you to tune you spray pattern, work on your overlap, and practice technique.

16 Comments

  1. Hi Please visit our Youtube channel for videos on the steps to painting a car yourself: https://www.youtube.com/user/EastwoodCo

  2. Hi I have ml320 cdi 2008 Mercedes Benz I need to paint the front fender but I never paint before can I paint it on my garage I have all the tools can you please tell me how to do it thankx

  3. The air control knob controls air pressure at the inlet. Not all guns have them.

  4. And the “Air Control” knob does what? You point it out but don’t discuss it.

  5. Mixing paint, reducer and hardner is listed on the side of each can. If shooting base coat/clear coat paint normally it’s a 1:1 ration, meaning 1 part paint, 1 part reducer. You should have mixing cups wit these ratio’s listed on the outside.. Your hardner is for the clearcoat, which these days is normally 4:1

  6. Bought this gun for auto restoration to replace my 15 yr old Accuspray Model 10. But first thing I tried it on was painting a set of custom cabinets with water borne lacquer. Works Great! Beautiful finish on the cabinetry. Can’t wait to see what it does with automotive finishes.

  7. i have finished spraying primer surfacer urethane on my fender . the fender had clear coat finish, i sanded down to the color base before repriming, and when i primered i got a crackle finish on some of the fender ? what happened?

  8. Why is there bubbles in my clear coat after it is dried?

  9. The surface on my finished paint job is orange peel very grainy & rough looking. No runs, good shine even color good in every other way. Base clear with PPG 2 to 3 coats base 2 to 3 coats clear 1.4 tip hvlp 30 psi?

  10. Hi I was wondering, do you have smaller paint strainers for the small cup spray guns ? I have one like your in the Demo . I tape up the strainer so I can use them, their must be smaller paint strainers yes ? no ? thanks for any reply. sandy graham ps good demo

  11. Like the gun, especially the feature at the inlet. Once I set up a website for the rental garage my son and I are trying to open up, we will be very happy to do a lot of business with your company.
    Perhaps if you’d like, maybe promotional advertising through our garage for you.

    Ps. Love all the equipment you advertise.

  12. Thanks,sometimes we forget.

  13. please do more training i have been auto restore for over 30 years an this is the best. all ideas is clear an easy to understand as long as you leave out the back ground music. can you cover the different temp reducers an problems that can happen during the paint job. like dirt, runs, dry film, an water born paints, love the info thanks.

  14. very well explained, hopefully you can give some insight on how to paint candy,that is the next phase of painting I want to learn, I am told it is very difficult to spray.

  15. I liked the video that Kevin displayed on how to do paint gun set up. I would like a video on how to mix your paint , thinner , reducer, and hardener and so on . thank you very much .
    Glenn Kinney “