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 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.
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).
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.
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.