Paint and airflow irregularities

Assuming your airflow is consistent, it sounds suspiciously like it may be insufficiently mixed paint ie. "soft" lumps in your paint causing a partial blockage and then blowing through, momentarily causing "blips" in your paint flow.

Turns out, what I was experiencing was the paint drying at the tip of the airbrush...maybe

Since I got my new regulator and filter hooked up, I was able to dial down the PSI and obviously got more control and precision. However, I noticed that after only a few minutes of airbrushing, the plaint flow got irregular and eventually got weaker and weaker. Even the airflow was reduced.

So I disassembled and cleaned the airbrush and everything was back to normal. My theory: at higher pressures, I was able to go longer without noticing the airbrush tip accumulating dry paint since I had the extra power to push paint through a smaller and smaller hole. But at lower PSIs, I didn't have this "reserve power" and as a result, I noticed reduced flow due to a smaller and smaller hole from the paint tip accumulating dry paint.

This still may not explain what happened earlier, but it might give more clues at the very least.

Yesterday I did some more painting and suffered from the irregular paint flow, even with a freshly cleaned airbrush.  I dialed up more air pressure from the compressor and the paint flowed as it should.

Perhaps one reason for this problem is that I'm not thinning my paint at all.  Maybe the combination of paint drying on the tip and/or thick paint are producing these results.  I have recently ordered the special "nozzle widget" from Dixie to help reduce paint dry, so hopefully that will help.

Hey man im new to airbrushing as well.  I also bought the Passche vl and like a 1.5 hp 2 gallon compressor.  I was wondering what type regulator you are using, where did you get it, how much???? also what compressor???  I hooked it up just to test the brush and wow with no way to regulate the air pressure i was all over the place.

jimski123 wrote:

Hey man im new to airbrushing as well.  I also bought the Passche vl and like a 1.5 hp 2 gallon compressor.  I was wondering what type regulator you are using, where did you get it, how much???? also what compressor???  I hooked it up just to test the brush and wow with no way to regulate the air pressure i was all over the place.

 Check out this post:

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jimski123 wrote:

Hey man im new to airbrushing as well.  I also bought the Passche vl and like a 1.5 hp 2 gallon compressor.  I was wondering what type regulator you are using, where did you get it, how much???? also what compressor???  I hooked it up just to test the brush and wow with no way to regulate the air pressure i was all over the place.

This is my compressor:http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93657

This is the regulator + moisture trap that I'm using: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43242

I'm using a different regulator than the one provided because the one that came with my compressor didn't work right.  Harbor Fright was able to take care of everything for me though, so no worries.

I can use my Paasche VL w/o any regulator (with my current compressor), as long as I'm painting something that doesn't require detail, like say...a modern nuclear submarine model (my current project).  Instead of messing with thinning, I have just decided to crank up the PSI on my compressor, which might not be able to provide the pressure your compressor provides.  One advantage of this is the mitigation of the paint tip drying effect and therefore I get more airbrush time before having to clean my tip.

thespaniard180 wrote:

This is my compressor: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=9365 This is the regulator + moisture trap that I'm using: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43242

For price of these two combined, you can get a much more powerful compressor which means smoother operation with less pulsation. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95630  The kit even includes a clone of the Badger 155 airbrush.

However, I don't recommend any of these Habor Freight compressors. Too many horror stories about their workmanship and durability.

 

 

thespaniard180 wrote:

I can use my Paasche VL w/o any regulator (with my current compressor), as long as I'm painting something that doesn't require detail, like say...a modern nuclear submarine model (my current project).  Instead of messing with thinning, I have just decided to crank up the PSI on my compressor, which might not be able to provide the pressure your compressor provides.  One advantage of this is the mitigation of the paint tip drying effect and therefore I get more airbrush time before having to clean my tip.

I wouldn't characterise thinning as "messing around". In most cases, it's essential to thin your paint for best resuts. Your spray pattern will be finer and your finish will be smoother. Even when painting with supposedly "airbrush ready" paints, thinning can be very beneficial.

If you're not thinning your paint and you're simply upping the air pressure to make it work, then IMO you may as well be using a spray can. You're only using a tiny part of your airbrush's capabilities.

Unthinned, your paint will be prone to spattering overly thick application, orange-peeling, and, due to the high pressure required to get your paint through your airbrush, considerable amounts of overspray. (And, as you have found, an increased tendency to "tip dry")

Thinning your paint will allow you to reduce your air pressure and work with greater accuracy, and, as described above, will produce better results.

What type of paint are you using?

 

 

I'm using Testors Model Master acrylics.

I still have significantly more control under higher pressure than with a spray can. Also, I get much more coverage, since I'm painting a larger model than some 1/72 or 1/48 WWII fighter.

I have absolutely no problem with orange peel or over application with high pressure. I still waste some paint from overspray and don't always get perfect paint flow, but so far, it's my most successful painting so far. Even under low pressure and perfect paint flow, I get so little coverage so I have to make so many passes over my model, so it's very easy to miss spots. I'd rather overspray and get better coverage than miss spots.

My special tip/nozzle should arrive today, so maybe I can use that and lower the pressure a little.

Basically, I want to avoid changing needles, tips, etc. while I'm in the middle of a paint job (not just a paint session, but the ENTIRE paint job, which lasts weeks).  I am using the #3 needle and tip and have spares of each, so I'm sticking with the #3.  I could go to #1 or 5 (whichever gives broader application), but I have no spares for those.

I've tested on half a dozen so plastic juice bottles and have gotten perfectly smooth finishes under high pressure.  By the way, when I say "high pressure," I'm talking around 25 PSI.  I'm defining low pressure as around 12-18 PSI.

I don't need accuracy for this project. I just need larger paint coverage.

keilau wrote:

thespaniard180 wrote: This is my compressor: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=9365 This is the regulator + moisture trap that I'm using: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43242 For price of these two combined, you can get a much more powerful compressor which means smoother operation with less pulsation. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95630  The kit even includes a clone of the Badger 155 airbrush. However, I don't recommend any of these Habor Freight compressors. Too many horror stories about their workmanship and durability.

I didn't read any bad things about those compressors on this site, although I didn't do an extensive search, either.

I knew I wasn't getting high quality stuff, but I only needed this compressor for one paint job and maybe this compressor was a just the generic version of the higher prices badger or paasche compressors.