Trouble with maintaining constant paint flow with Paasche H airbrush and a question about how to spray more crisp edges on camouflage

Well as to painting in cold, you're describing how that can go lol ! Not saying it did at 40f but it can. But added to that with acrylics I always prime and with solvent paints I pretty much also always prime. Just with acrylics it's vain imagination to think you don't need to prime even if the paint goes on ok, because it will scratch and or peel exponentially more easily with added coats after fully dry . Primer is your bond to the plastic but acrylics bond well to primer. You need to build an acrylic finish, you can't just blast some paint on and think it's goiong to work out for ya.

That said, primer or not put down a very light mist coat of color and let that flash off. You might barely see color on this coat and a little more on the second coat and let that all flash off. You can use air from a hair dryer or from your airbrush ( air only, don't let the paint out) to flash it off more quickly. It will flash quickly with acrylics anyway but this speeds it up between coats.. Now you can build your color coats and the paint will stick vs sliding all over the place much as has already been mentioned. Get progressively wetter. Those two base coats will use very little paint but they are part of your building block for the last coats. And very important to build on, all the more so if metallic. Think at least 3 coats total as a minimum for general paint jobs but probably 4-5, the last being the wettest. Now with Tamiya you may only need one of those first very light coats especially with alcohol or LT as thinner, it's fairly forgiving paint. But full waterborne paints are trickier and need the two base coats generally speaking.

How to spray acrylics or a name very close to that by Barbetos Rex is out there on you tube. He demonstrates this perfectly in the video and takes his time in all his videos. He might get carried away with some things and some folks may not like him but he's got this part down right. Go look for that. If I find the link I'll post it here in this thread.

ScaleModeler_1973

Oldermodelguy, sorry, in re-reading your earlier thread, I see you recommended polishing (not filing/sanding) of the needle tip on a Master Airbrush. Apologies for my getting cofnused...So could you please elaborate on how/how much to polish the needle? Thanks.

 

I polish my needles so they are shiny. I may or may not use paper depending how dull or if there is a slight burr at the tip. If I use paper or more likely micro mesh then 1500 and 3000 cradling the needle between two fingers and squeezing. With the other hand spin the needle then run the paper out to the tip. Repeat two or three times. Now I use Colgate tooth paste on a piece of paper towel and repeat. You will see black on the paper towel. Do this as many times as it takes to begin removing the dullness. Now I go to Formula One Scratch out and repeat again using tissue paper. Take a damp piece and wipe clean then dry. The needle should shine like polished stainless steel. Wipe again, you're done. Assemble your airbrush and give it a try. Understand that not all needles need this, some are quite shiny and the tips look fine through a magnifier. But for those that do need it it can make quite a difference even with something like a Badger, not just Chinese knock offs.

I only polish out from about mid way of the needle to the tip. It doesn't take long at all and the atomization and pattern can be quite noticably improved.

ScaleModeler_1973

I tried airbrushing tank tracks (plastic links on their sprues) with dark iron Tamiya paint (thinned with X-20A yesterday) using a Master airbrush, and I had a pretty hard time getting the paint to adhere. The paint kept 'sliding around' on the surface of the pieces, getting shiny, but just not darkening. I had to make several passes and only fully depressing the trigger (discharging a ton of paint) really allowed the paint to really somewhat take. Even after using an entire small jar (10ml) of the dark iron paint, one can still see the dark yellow (original sprue color) on the pieces. I did not think it was necessary to prime sprue tanks tracks (because of their relatively small size), but maybe that was my first mistaken assumption?

I prime everything with decanted Tamiya Grey Surface Primer through my airbrush, which helps significantly with keeping paint from sliding around like you describe.  But, that may not be the biggest problem you're having.  It sounds like you might be trying for complete coverage in one pass, which will also cause paint to slide around, even on a primed surface.  What you want to do is make several passes with the airbrush (and this includes when you're putting primer on the model), getting progressively closer to what you're painting with each pass.  This builds the paint coat up in several, extremely thin layers and the first layers give the subsequent layers something to sort of "join hands with" so you can get good coverage without blowing the paint you just put down off the model.  It seems counter-intuitive, but a higher volume of paint isn't the way to go for good coverage...the paint goes on too wet, and the air blast from the airbrush pushes it around on a surface it hasn't had a chance to adhere to yet.  In this case, less is more.  That being said, I don't build tanks so I don't know this for sure, but its my understanding that track links in a lot of those kits are more of a vinyl, which presents unique challenges for getting paint to adhere to them.  I'm sure the guys who do build tanks have good methods for dealing with that.

ScaleModeler_1973

Secondly, maybe the fact that my narrow time window for airbrushing is just after sunup (about 7:00AM) and that the temperature was in the low to mid 40's had something to do with the crummy results I got? I had planned to airbrush some camouflage using Tamiya paint and isopropyl alchohol later in this paitning session, but I decided not to try because I was thinking maybe the weather conditions were not suitable...

You're definitely on the right track there.  Temperatures that are too high or too low will have an effect on your painting results.  If you use lower air pressure and lower paint volume, you'll solve that problem as well, because you'll be able to paint indoors.  When I first got my Paasche H when I was 15 years old (the same one I use today at 51), the whole point of getting an airbrush for me was so I wouldn't have to paint outside like I had to with rattle cans.  Since day one I have always used a low-pressure, low-volume painting technique that results in nearly all of the paint going on the model instead of being scattered into the air in huge clouds like I have seen so many modelers on YouTube doing.  When I have to hold a part with my fingers while airbrushing, I may get a tiny bit of overspray on my fingers...but that's the extent of paint going places other than the model.  That also results in very little odor that only lasts a few seconds.  Tamiya paint is probably the most odor-free, MRP lacquer is second, and enamels are the worst (takes the solvents forever to evaporate).

Oldermodelguy, sorry, in re-reading your earlier thread, I see you recommended polishing (not filing/sanding) of the needle tip on a Master Airbrush. Apologies for my getting cofnused...So could you please elaborate on how/how much to polish the needle? Thanks.

Hello. This is probably a really dumb question, but how do cool temperatures affect outdoor airbrushing? I tried airbrushing tank tracks (plastic links on their sprues) with dark iron Tamiya paint (thinned with X-20A yesterday) using a Master airbrush, and I had a pretty hard time getting the paint to adhere. The paint kept 'sliding around' on the surface of the pieces, getting shiny, but just not darkening. I had to make several passes and only fully depressing the trigger (discharging a ton of paint) really allowed the paint to really somewhat take. Even after using an entire small jar (10ml) of the dark iron paint, one can still see the dark yellow (original sprue color) on the pieces. I did not think it was necessary to prime sprue tanks tracks (because of their relatively small size), but maybe that was my first mistaken assumption? Secondly, maybe the fact that my narrow time window for airbrushing is just after sunup (about 7:00AM) and that the temperature was in the low to mid 40's had something to do with the crummy results I got? I had planned to airbrush some camouflage using Tamiya paint and isopropyl alchohol later in this paitning session, but I decided not to try because I was thinking maybe the weather conditions were not suitable...

Oldermodelguy, could you please elaborate a bit on sanding/filing the needle on a Master Airbrush (what grit of sandpaper and how much should I sand off the tip of the needle, etc.)? Many thanks.

 You can get fine lines with G43 and .3 tip or .2 tip and needles. It helps tremendously to remove the metal pedal cap at the front of the airbrush and use it with the exposed needle tip. Spider webbing and pushing paint to the sides has more than one cause, too high a pressure yes but also too high a pressure for how thick you thinned the paint matters. I suggest your paint is a bit too thin and that's why even 10 psi is pushing out the center. Additionally paint flow. Use the needle stop on the back of the G43.

I have the Ganzton airbrush for my double action work, same as the G43 for all intents. And I do artwork with it with Createx paints, craft paints and artist acrylics. And the fine work on models with either that brush or my Badger 200 with .25 tip. Anyway, cut your paint flow back and build it up over more than one pass for hard surfaces like models. I only mix about 25%- maybe sometimes 40% reducer with that .3 tip and on paper or cloth fabrics I shoot high pressure. Practice what I've said in this message on an old model or one you can strip the paint and reuse, you will get the right combo. And the IPA will have a different action and drying rate than the Tamiya thinner does.

In winter with any acrylic paints I just shoot my models into a trash can with papers inside. For solvent paints I use a booth or step outside on a sunny day. Artwork the paint is thick enough and working so close for fine lines like you're doing just a fan is fine. I'll spray at the kitchen counter with no over spray getting onto anything. On the Createx paints I use straight 70% IPA or the Createx 4011 reducer, it takes more of the reducer than the alcohol to get the flow I'm looking for. But if you polish the needle you can get down to almost an invisible mist with Tamiya acrylics that just kind of collects on the surface when you spray in close. About three passes will get you color and no spider webbing. You likely need to use the needle stop to do this. Don't expect a full wet coat on the first pass, get some paint on there and flash it off then put it down wetter after it has something to stick to.. But you will find your own way, these are just tips to help you get there. Let us know how you make out. I don't let weather stop me from airbrushing lol.I've always found a way to paint for over 60 years now.

Hello. I'm unfortunately rained out this weekend (my mother's outdoor patio is the only place I have to airbrush). Last weekend, I tried airbrushing dark green (third color) to complement the dark yellow background with red brown striping I had painted on my 1/48 Nashorn. Not quite wanting to give up on using Tamiya X-20A thinner (as I had already bought several bigger bottles of the stuff), I used it to thin my paint this time, too. (I know a couple of you guys [eaglecash, oldermodelerguy] have been coaching me for a while to give isopropyl 91% alcohol a try). Well, I'm finally ready to take your advice: my green striping turned out really crummy (using X-20A): It looks like segments of a caterpillar (hollowed out, with more paint on the outer sides and translucent-looking on the inside). Some 'spidering' on the outside edges in places. I guess I had a really hard time controlling the paint flow with this double action (Master G43) airbrush. What really confuses me is that I am getting this kind of 'hollowed out' effect (with paint pushed to the outer edges) even though I'm already down to about 10 PSI when the trigger is depressed (which I have read in books means the air pressure is too high)? (So I don't know how I can reduce the air pressure much more on my regulator and still be able to spray?). Anyhow, I bought myself some 91% isopropyl alcohol from a local drugstore and look forward to experimenting (using it as thinner with my Tamiya acrylics) next time. 

Thanks to Eaglecash (and maybe a couple of others, too) for the tip/suggestion (shared on a couple of threads) about using a cheap electric toothbrush and 91% isopropyl alcohol to scrub off acrylic airbrushed paint (while I still have several built models awaiting airbrushing, I will probably buy said toothbrush so I can start anew with airbrushing models like my Nashorn that didn't turn out very well the first time). Traveling next weekend, but hopefully there will still be some decent fall weekend weather (dry and not too cold) before I have to close up for the season...Thanks.

For camo, I've found that paper masks/templates work well.  Just cut out the desired shape, place a loop of tape on the mask, and stick it to the model.  The edges of the mask sit just a bit above the surface so that you get a fairly (but not perfectly) crisp line.  If truly crisp lines are what you're after, just cut masking tape to the desired shape. Tamiya's white flex tape is great for masking out curved regions. 

Here is a pic of the process: https://meatchicken.files.wordpress.com/2022/03/camo2.jpg and 

https://meatchicken.files.wordpress.com/2022/07/img_3320-1.jpg.  

Here's what the second one looked like when finished: https://meatchicken.files.wordpress.com/2022/07/img_3357.jpg

Good luck!

ScaleModeler_1973

Oldermodelguy, OK thanks for explaining that what I am experiencing is tip dry and for recommending how to prevent it. One follow-up question: in addition to using alcohol to thin my paint, would it be helpful to put a few drops of Tamiya retarder (mixed in with my paint), too? I have a few bottles of this retarder, but am not sure if it is only for hand brushing paint... Ironically, I already have a Master G43 (and plenty of spare parts for it)-it is the first airbrush that I have ever used, but it has sat idle for a long time since I started using the Paasche H instead. Interestingly, I have not had major problems using the Master G43 on big surfaces like my 1/16th scale motorized tanks: I don't think I really know how to 'consciously' control the paint flow that well, but I managed to do OK (reasonably even coat on my big tanks). Maybe it is time that I give it (a double action airbrush) a try on my 1/35 and 1/48 models, too, though. I think that I have maybe gotten 'tunnel vision' with only using the Paasche H. Follow-up question: what do you mean about polishing the needle (could you elaborate)? Oh yeah, and thanks for the tip about tilting inward my airbrush when I paint camo stripes so that it will feather over the area that I want to cover over in the middle.

 

Tamiya retarder should work just try it and see. I've just always stocked Liquitex because of art work, craft paints and artist acrylics but it's made to go in any acrylic paint and thus far has just by way of the thinner I use..

You can get in tight and make fine lines by removing the pedal cap on the front of that G43 ( you might have to play with air pressure a little bit). You will gain much control with that brush once you learn it's ways and gain some muscle memory but it's still difficult to make it around a curved surface without a mask of some sort. You can do fine lines yes, but you need to keep equal distance to the surface going around curves.. My Ganzton is basically the same brush, learn to use the fluid stop on the back. I like the .3 needle for art work etc. But have used the .2. You can easily make a pencil line sharp line with the .3 then move further from the work to fill in and the .3 can handle a little thicker paint mix aiding in not spider webbing or full blow outs. I would only use the pedal cap on the front on broad paint work, maybe painting a whole tank hull it's base color etc. For any finer work remove it. Course for the heavier work you probably use the H as I generally do.

IDK, my choices blow in the wind so to speak. Hope any of this helps more than hinders lol !

ScaleModeler_1973

Eaglecash867, thanks to you and others for the tip about using 91% isopropyl alcohol. I guess I incorrectly assumed that Tamiya (X-20A) thinner worked best (and was somehow specially designed) for use with Tamiya acrylic paints and purchased a decent stock of this thinner. Now I know better and will give the alcohol a shot....Having said that, are there some cases where X-20A is still useful?

 

Not that I'm aware of.  X-20A was the reason I almost gave up on getting the results I wanted with Tamiya.  Then I took a shot on something I already had anyway, the isopropyl alcohol, and that worked amazingly well for the way I airbrush.  I definitely do it differently than a lot of the guys I see making videos about it on YouTube.  With the clouds of paint they lay down like its coming out of a firehose, it makes me wonder why they don't just go back to using rattle cans.  Makes me cringe...LOL.

Another tip on Tamiya stuff:  If you ever decide to decant and airbrush Tamiya's Grey Surface Primer, don't use isopropyl alcohol to thin that.  The chemical reaction between the two turns the primer into grey cottage cheese.  For thinning that, I use MEK.  MEK by itself is murder on plastic, but when properly used to thin primer you're going to airbrush, that plastic solvent quality is just enough to give it a really strong bite on the plastic (without damaging it).

Something that will also help with getting consistent paint flow is to mix your paint and thinner before it goes into your airbrush.  I use the little Dixie paper bathroom cups to mix paint and thinner in, and then pour that thorough mix into the airbrush.  That ensures that you're not going to suddenly hit pockets of thinner or thicker paint because you didn't get a good mix in the airbrush cup.

Just an example of the precise, fine atomization that is possible with your H:  I'm in the final stages of my F-4B build, and although I'm not a rivet counter, getting it as historically-accurate as possible is a big thing for me.  I realized just the other day that there was an antenna they say to install on the belly that wasn't installed on F-4Bs in 1965.  The problem is that the whole thing is already painted, decaled, and weathered, and where the antenna is supposed to go?  There's a GIANT depression (well...its actually less than 1mm wide...LOL) in the skin that the antenna is supposed to go down into.  There were decals less than 1/4" away from where the depression was, and I was going to have to mount the antenna, slice it off at its base, use a chisel blade to level it with the skin, fill the remaining tiny gaps with super glue, sand, primer, and paint.  YIKES!  But, I was able to pull it off.  The only masking I did was to stuff a little chunk of Silly Putty into the nose gear well, since I had to primer and paint right to the edge of that.  I was able to put fine, pencil-thin primer and paint lines down to match the surrounding paint.  Just have to replace a couple of decals that got damaged during sanding and re-weather that spot...but you have a good airbrush that is capable of a lot of things.  Just keep practicing with it.  You'll get there.

I think I understand what you mean. Thus far, I have only painted my 1/16th scale tanks in monocolor, but I think using silly putty/masking with tape on them to paint camouflage patterns would be a lot easier (and more effective) than on a 1/35th or 1/48. As it is, in painting my 1/48th scale Nashorn, I made the mistake of leaving too little dark yellow between the red brown stripes that I put down. And LOL, I haven't even gotten to spraying the third color (dark green) yet....Thanks for sharing your experiences.

Oldermodelguy, OK thanks for explaining that what I am experiencing is tip dry and for recommending how to prevent it. One follow-up question: in addition to using alcohol to thin my paint, would it be helpful to put a few drops of Tamiya retarder (mixed in with my paint), too? I have a few bottles of this retarder, but am not sure if it is only for hand brushing paint... Ironically, I already have a Master G43 (and plenty of spare parts for it)-it is the first airbrush that I have ever used, but it has sat idle for a long time since I started using the Paasche H instead. Interestingly, I have not had major problems using the Master G43 on big surfaces like my 1/16th scale motorized tanks: I don't think I really know how to 'consciously' control the paint flow that well, but I managed to do OK (reasonably even coat on my big tanks). Maybe it is time that I give it (a double action airbrush) a try on my 1/35 and 1/48 models, too, though. I think that I have maybe gotten 'tunnel vision' with only using the Paasche H. Follow-up question: what do you mean about polishing the needle (could you elaborate)? Oh yeah, and thanks for the tip about tilting inward my airbrush when I paint camo stripes so that it will feather over the area that I want to cover over in the middle.

Eaglecash867, thanks to you and others for the tip about using 91% isopropyl alcohol. I guess I incorrectly assumed that Tamiya (X-20A) thinner worked best (and was somehow specially designed) for use with Tamiya acrylic paints and purchased a decent stock of this thinner. Now I know better and will give the alcohol a shot....Having said that, are there some cases where X-20A is still useful?

My biggest challenge in spraying camo is often scaling the fade.  What I mean by that is how much distance it would occupy in real life vs our models.  From what I've seen, the "fade" on most fighter jets is probably less than 6" in width.  Of course, that corresponds to less than 1/8" on a 1:48 scale model.   Basically, not a hard tape line, but pretty sharp on the contrast.  

For soft edges to camo patterns, you can also use masking tape and then lift the edge of the tape just a hair.  It does the same as using Silly Putty or poster tack-you get a little bit of a lift at the edge, with a little "underspray" and a soft edge.

I don't know, how about silly putty masks ? I know it's old tech but it does work for a semi soft/sharp edge.

I'm only an occasional armor builder though, some of you guys are pros at it. Seriously. I just run two fine lines and fill it in same as I'd do in airbrush art work.

Tojo72

Are those sheets of the same material that Tamiya uses for their canopy masks,could be useful.

 

Yup, they appear to be the same stuff.  They have a couple of types, one with a 1mm grid printed on them, and another with no grid.  The 1mm grid paper is also kind of a cool way to take measurements on curved parts.  Superior alternative to masking tape as well, IMHO.

Are those sheets of the same material that Tamiya uses for their canopy masks,could be useful.

oldermodelguy

Though the 200 produces much finer atomization that can be cut back to vertually an invisable mist in the air but slowly builds on the surface of the model ( has that potential if someone wants to cut it back that far been there done that).

I can do that with the H, it just takes practice with technique and thinning.  Never needed anything else.  I paint everything with it, including instrument panels (short of the knobs and switches of course).

I use a variation of "the sausage technique" that Keavdog uses for camo patterns.  Used frisket film for my area masks and Blu Tack for the sausages to feather the edges on these wings (F-111F and FB-111A).  The paint wasn't Tamiya though, it was decanted Model Master Enamel rattle cans.  I imagine it'll be even easier now that I have discovered Tamiya Masking Sticker Sheets.

Also denatured alcohol as thinner will help keep the tip wet when the brush is off but it flows out more than IPA. So will retarder slow the tipdry ( I use Liquitex Slow Dry retarding medium personally). Start your lines off the model, then if it spits it doesn't spit on the airplane. When you do the outline fine lines that you will fill inward from tilt your airbrush towards that fill in area and the feathering will go to where you will fill anyway. You will get a little soft edged line but not anything like you are showing us. I think it's satisfactory. I can do this with an H and the #1 tip which is a .45 needle acceptable for this kind of work once you conquer that tip dry issue. And make no mistake, you're getting tip dry as based from what you describe. In art work we routinely use .3-.5 for this kind of line and fill in, though I actually like .2-.3 personally for finer lines for say T Shirt lettering for instance.

Arguably it can be done with the H yes but double action would be easier once you get control of it's function. Even an inexpensive Master G43 ( just polish the needle) would do this work easier. But it can be done with the H. My Badger 200 is good for this with the .25 tip and it's single action. So single action does work. Though the 200 produces much finer atomization that can be cut back to vertually an invisable mist in the air but slowly builds on the surface of the model ( has that potential if someone wants to cut it back that far been there done that).

Ditto on the alcohol - I thin Tamiya 50-50.  I use the H but mask using the sausage technique

This is a 1/144 kit

MJY65

IMO:  The H is a pretty crude airbrush for painting camo.  

Not really.  Just takes practice.    That being said, I still prefer to mask for camo patterns...just makes it less risky.

To the OP, have you tried thinning your Tamiya paint with 91% isopropyl alcohol?  I have found that to be the best thing to thin it with if you want consistent flow so you don't get the tip drying that is causing the sudden splotches of paint when you're trying to do more precise paint work.

IMO:  The H is a pretty crude airbrush for painting camo.  It does fine at painting larger areas.