Thread: Paint on trigger release.

Funny you should mention the problem of spots at the end of a line, I was having that same problem last night but only with one of my airbrushes of the two I was using. The one giving me the problem was my Harder Stenbeck and I have a DVD that I know covered that problem. So I just got done watching the troubleshooting part again and they said it is most commonly caused by releasing the trigger to abrutly (fast). I'm not sure if thats my problem or not but I'm going down to do some painting and I'll see if thats the problem with that brush. I was doing everything the same with my other brush and wasn't having that problem. I will say it was only with my black paint and it didn't seem to do it after thinning the paint more.

I'll let you know if I come up with anything later on.

Good luck
Cliff

wokka and cdv, I have a dead spot in my trigger action too, and get the same fat spot when decreasing paint flow problem. Perhaps it an inherant situation with many different brands of AB. I have two Iwata HPs and the more expensive BCI Plus has the most trigger lag of the two.

I can pull the trigger back an 1/8 to 1/4 inch before I get any paint to spray out, and always have problems getting it to start a fine line where I think it will start a fine line. I end up repeating strokes a lot to get a line to start, then just taking what I get, rather than getting what I want. So to speak. LOL But am working around this issue. It does tend to decrease confidence levels in attaining consistancy, and achieving precisely placed detail.

I'm wondering if others here on the forum have the same paint release delays in their trigger action? I'd like to hear from more people on this one.

Greger

The "paint delay" you are talking about is usually caused by paint that has not been properly reduced (thinned) or mixed, and or a dirty needle & nozzle.
Instead of the paint flowing normally down the length of the needle tip, it hesitates because the paint is so thick and sticky that it is easier for it to resist the vacuum or suction created around the nozzle opening than it is to just flow out smoothly. Dirty needles and nozzles give the paint something more to grip or hold onto in the normal paint flow path.

The spurt or splat of paint at the end of a line, or the start of the next line is usually caused by releasing the air too quickly or by stopping the flow of air before you stop the flow of paint. That leaves you with a tiny quantity of paint just waiting at the tip of the nozzle waiting for the air to start up again. By releasing the trigger too quickly on the air half, you can end up kind of pushing that last little bit of paint out of the brush as a drop of paint rather than letting the airbrush atomize it like it normally would when spraying.

Remember, ALWAYS start and end each stroke with the air ON.
Work the trigger in smooth, consistant motions like you were petting a catterpillar. That smooth motion helps you learn to control just how much paint you are releasing. Often times, the control issue is directly related to how you hold your brush and trigger. People who spray while holding their brush in a fist often have a hard time with the fine control. Their hands and fingers tend to take each motion in their extremes, either on or off, and not a whole lot in between.

Remember to keep cleaning the needle as you go as well, I've just put the fine needle in my Badger 150. I keep a soft bristle toothbrush handy cos you I just cant get my fingernail in that gosh darned crown cap every once and a while I get a faint line after releasing the trigger (Im still practicing myself) its a sign the needle needs cleaning again as the smaller needle gloggs easier I'v found. I don't seem to have a dead spot on my trigger though! I may just have gotten used to it and just not notice.

this is interesting! i do use a "fist", i have a "dud" wrist and to use my index finger on the trigger is not possible, so i use my thumb, and of course probably hold it too tight as a consequence! never thought of it! i will try and "lighten" up a bit, thanks for that, riki.

Keep in mind that while the abrasive levels you use in your emory board are typically fairly fine, that they*are abrasives. This means that you are grinding away the needle when you use them, and the chances that you are keeping the needle perfectly round and in the identical matching shape for the interior of the nozzle are slim to none. If your needle is not polished to a shiny surface when new, then you might try a fine jewelers ruge or toothpaste to polish it up. But you should only need to do that on a new needle. If you keep your airbrush and it's parts clean, then the needle should be nice and shiny after every cleaning. If you don't clean your brush thoroughly, then the brush can start to deteriorate in it's capabilities, and in yours when you use it. I'm with you, I would much rather start each painting sesson with the brush in pristine condition, it leaves out any doubt about problems or challenges that may arise. It eliminates the airbrush from the potential causes.

The use of the brush for cleaning the needle tip is good. Keeping the brush sitting in a cup of water between uses also lets you keep the needle tip and needle cap clean, without the potential damage caused by trying to pick at it with your fingernails.

The "petting the catterpillar" is more of a line of thinking, by keeping your finger motion and pressure gentle and smooth, you help avoid the sudden blasts or stoppage of paint and/or air. Your finger basically does a good imitation of a catterpillar or inchworm as it would normally move/walk. Holding your airbrush gently with your fingertips helps you avoid cramping and shaking because of muscle tension. Controling the button/trigger with a relaxed and extended index finger lets you work in a normal range of motion rather starting in a closed fist and trying to clench that fist even tighter to control the flow, depth and direction of the paint you are spraying.

like you were petting a catterpillar

Great analogy!

Rockie

Another common cause for the heavy spot at the end of the stroke is the fact that you are stopping the motion or movement of your hand accross the paper or work surface before you stop the release of the paint, so you end up spraying a concentrated spray at the end of the line.
Part of the practice and experience you get over time is to get your timing down to tighter tolerances. Anticipating the end of the line and easing the trigger forward 'til you get the paint flow and arm movement synced perfectly.
While the tranparent paint is more forgiving, it doesn' help you fine tune your skills as well as the opaque black does. And yes, you can do those tiny fine lines with the opaque black paint and not get any blobs or heavy dots at the end of the stroke. It just takes practice.

Without seeing an example of the actual results, it's kind of tough to do an exact diagnosis of the problem and give a solution.

Between all the possible solutions, they ought to be able to get their problems sorted out.

Let us know if it doesn't work out for you though.

White always has a thicker/heavier pigment. Some paints do in general, and while it's great for coverage, it can be a real pain for fine control and detail work. If the particles of pigment are themselves really thick or large, then you can only do so much with the paint. It sounds like you are performing a good mix on the paint, and probably a good reduction on it too. Do you strain your paint before it goes into the brush? The class's translucent version of the paint has a smaller pigment size than the version you are using at home. Maybe try a different batch or make of paint.

Mickey Harris's "Ball of Death" will change size depending upon how far you have the airbrush from the paper, and how much paint you are spraying out at the time.
As I said, your airbrush doesn't know whether you are moving your hand or not, it just knows whether you have the air on and whether you have paint coming out or not.