Tamiya F4F-4 built as FM-1 Wildcat - 1/48 - FINISHED

[Landlubber Mike]

2 hours ago, Peterpools said:

Mike

So your working pressure is between 18-22 which sounds fine but not sure why you turn down the working pressure when actually shooting. I also tend these days to use a .5 tip Iwata Revolution for clear gloss and flat coats rather then the customary .35 - just helps in applying more even coats. 

Of course, looking at the final results, they look perfect.🏆

 

Sorry, I fear that I'm confusing everyone with what I have been saying.  When I shoot the GX100 clear, I find that it takes the airbrush a little while to be able to start spraying the clear as if I was spraying Mr. Color, Vallejo, etc.  Either nothing comes out initially, or just a tiny bit of spray comes out.

One thing I have done is just keep spraying (off the model) until the airbrush is spraying a full spray.  That sometimes takes a while, so what I've done in the alternative is to turn the PSI up to 40-60, and spray off the model until the airbrush is going at the proper rate.  Once that point is reached, then I turn it back down to get the working pressure of 18-22 and start spraying the model.

In both cases, I feel like it takes a bit of time for the thinner to work through the nozzle, etc. to get to the full spray point.  Spraying at a higher PSI just helps push the mixture through the airbrush to get the airbrush innards primed enough with thinner to get to proper spray patterns.  I think I'll try using a 0.5 airbrush next time, and using Rob's approach of shooting some thinner through the airbrush before starting with the GX100.  

 

[Peterpools]

Rob

That's very interesting that you see a drop in PSI from the set pressure to the working pressure. In my case, the larger the tip, the greater the difference seems to be. I'm only guessing but that may have to do with the sensitivity of the gauge, the range the gauge covers and then all the normal stuff we talk about so much: the air brush itself, length, width of the air hose and then all the paint characteristics after thinning. Everyone's setup is different and all that really counts, is what works. 

 

 

 

[Landlubber Mike]

I actually manually turn the PSI up on my compressor to get the airbrush primed.  Once the flow is going the way it should, I then turn it down on my compressor to my working PSI.  Sorry for all the confusion!

[Peterpools]

Mike

Once clears or paints are in the air brush cup, I hit the trigger once to make sure all is well and I'm off. Something doesn't sound right if you have to first clear the air brush or nothing is coming out. If this happens with just the clears, they are too thick for the air brush set up and working pressure. If it happens with the normal colors as well, there is a blockage in the air brush somewhere. 

After every painting session, I completely break down the air brushes used and thoroughly clean them. A good deal of the time I might also do this when changing paints from different manufactures and never alternate between acrylics with lacquers. Model Air is always used with its own dedicated air brush. 

[Landlubber Mike]

It's quite possible there is residue from a prior painting session, but I also break down the airbrush, and try to thoroughly clean out the nozzle, needle, etc. I only have this issue with Mr. Color's clear.  It's just so thick, and even thinning it 2-3 parts thinner to 1 part clear, I'll get the gummed up issue when starting to spray.  After maybe 10 seconds of continual spraying with maybe some back-flushing, I'll get a bit of spray to come out.  Then maybe after another 30 seconds, it will start coming out the full spray.  

I really don't have this with other paints and clears.  My primary airbrush is an Iwata Eclipse with a 0.35 nozzle.  I think what is happening is that some of the clear isn't completely dissolved in the thinner, so it settles and gums things up.  Eventually, as more and more thinner/thinned mix is pulled through the brush, things get more dissolved.  As I'm typing this, maybe what I need to do is pre-mix the clear and thinner before adding it to the cup.  I don't have to do that with other paints and clears, but maybe it's worth trying that out here.  Hmm...

[Peterpools]

Rob

That's very interesting that you see no significant drop in PSI from the set pressure to the working pressure. In my case, the larger the tip, the gr I'll see a  I'm only guessing but that may have to do with the sensitivity of the gauge, the range the gauge covers and then all the normal stuff we talk about so much: the air brush itself, length and width of the air hose itself. Everyone's setup is different and all that really counts, is the results and what works. 

 

[Peterpools]

Mike

All Mr Color paints and clears are very thick and require a lot of their thinner. I always thin and mix paints prior to adding the mix to the air brush as I was never convinced mixing in the AB cup is the best way to go, especially with thick paints. One of my most used air brushes is the Iwata Eclipse with a 0.35 nozzle, which I had for a good ten years and prior to it, I had another Iwata Eclipse.  Just love the way they shoot and for the most part, they are bullet proof. 

My other go to AB's are both H&S CR Plus with a .2 and a .4 tip. When it comes to breakdown and cleaning, the H&S is so much easier to do and doesn't require and tools and every inch of the H&S AB's are easy to clean. I find on the Iwata Eclipse, actually cleaning out the passageway through the tiny opening into the barrel portion, very difficult to do and that may be where the clog is.

One other area to check is the piston mechanism on the Iwata, which I had to replace just once, as the trigger would begin to stick. But for the amount of use I've given it over the years, an awesome piece of equipment. For gloss coats I use an Iwata Revolution with a .5 tip. As the tip size widens, I do need to increase the working pressure.