As promised..
This is my gravity feed gun. I have used this exclusively for past three years. Provided I keep it well cleaned, it should see me through to the end of the restoration\s. It never misses a beat. One curious eventuality though, the 'chrome' plating is coming away in serveral areas where my hand holds the gun. I believe the sweat penetrates to the metal beneath, and causes breaking down of the surface finish. Doesn't bother me. Nothing falls off onto the fresh paint.
The paint volume adjustment is the knob at the back of the gun. In the exploded photo, you see the fluid needle and spring assembly. It works in the same way as a needle does in a carburetor. Turn the knob fully in, paint flow is ceased. The volume of paint being atomised increases as the knob is turned out. When using the Protec Barrier Enamel (I also use hardener) I turn the knob three full rotations. I like a LOT of paint coming out. You get less dry spray that way, provided the correct ratio of reducer is used. The adjustment would be different for other type of paints, and other individuals.
Now, because I want a high flow of paint, I need to increase the spray fan pattern. That is the round knob in the upper middle of the gun, on the side facing camera. My spray path height is around 13cm, or 5" for those in non metric countries. If I need to paint something restricted, say, inside a tube or somewhere hard to reach, the fan pattern should be narrowed significantly. Air flow should be reduced heaps too, or you will send such a blast of paint in there that it is bound to run everywhere. Depending on where that place is, you might WANT a heap of paint in there, especially if you need good surface coverage without being able to see there after everything is put back together.
Speaking of air flow rate, my gun has air flow adjustment knob at the base of the hand grip. Some don't. If yours doesn't, get an attachment to put between the gun handle and the air hose fitting. Most of the new ones have a swivel, so you don't get the air hose hanging down further and dangling in your fresh paint. That's no fun at all. In fact, that's another reason why I like gravity feed guns. You don't have a big pot hanging below the gun, just waiting to either swipe a nice mark through the paint, or leaking paint out of the breather hole. If you are really lucky, the pot may even come off entirely. That is hilarious, provided you are an observer, and not the one doing the painting. I have seen this occur from both sides of the fence. With a gravity gun pot, it's always above the gun (naturally) and cannot drag through wet paint. In the above exploded view, you can see the little blue cap that pushes into the pot lid. It can be turned 360 degrees. Unless you are spraying something from underneath, the breather hole in that cap should ALWAYS face the back of the gun. Don't forget to reverse that if you DO want to paint upwards. You can alter the breather hole on a suction gun pot too, but because of the sloshing movement of paint inside the pot, drips are a common occurrence. Once again, this is only funny when it's your paint job!
Having mentioned the settings I prefer, I should advise the importance of keeping the spray gun at a 90 degree angle to the surface being painted. This is VERY important, and cannot be stressed too greatly. If your panel curves in any way, you must match that angle change with your spraying angle accordingly. The only time I ignore this rule is to either blend color into another panel (referred to as Wetting Out), if I am applying over thinned paint, or deliberately trying to reduce gloss level. This can be achieved by spraying a light coat with considerable additional thinners / reducer. On that subject, ALWAYS use the correct thinner, reducer, hardener, and flattening base for the paint you are using. Be sure to ask the paint shop for the Tech. or Spec. sheets for your chosen paint. It will tell you mixing ratios, surface preparation, interval between coats, total drying time, cleanup, and most importantly, SAFETY REQUIREMENTS. if you spray some paints in an enclosed area, without the correct PPE, you can die! You won't know how good your spray talents were, if you are too busy being dead at the time. Some paint gives off isocyanates, which is akin to cyanide gas. Lungs eaten away by inhaling that stuff will be permanently damaged. Ask someone with emphysema how they feel.
These are the mixing cups I like. Very easy to see the ratios, and there are any ratio you will come across, marked on the sides. They're easy to clean too, and double as something to put all the parts of the dismantled spray gun into, once painting has finished. I only use a metal stirring stick. They won't shed little bits of wood, won't split, clean exceptionally well (even if you let paint dry on it, just scrape it off later), and also have mixing ratios, if you don't want to buy the plastic cups. Both the stirring sticks and cups are very inexpensive. So are the disposable cone shaped strainers. I don't worry about contaminants in the paint until I'm ready to pour into the paint pot, then I sit a strainer into the pot and pour away, with no fear of muck ruining a good paint job, OR blocking up the gun from inside. I also like the screw on pouring spouts. Much better control of volume coming out, with those, and also use a clip on pouring lip for the paint cans. Dont forget, NEVER return mixed paint to the original can. If you have extra, put it in another clean can. If you used hardener, you may be able to use it for a number of days, depending on temperature and amount of hardener added, it will congeal in near future. Better of using any extra paint by putting another coat on your project, or use it to brush onto bolt heads, screws, surfaces you can't get spray onto, etc.....
One final piece of magic. Tac cloths are a sticky gauze material, designed to be lightly wiped across the surfaces to be painted, after they have been blown clean of dust etc. and then cleansed with Prep Wash or similar wax & grease remover. When I say 'lightly' wiped, I mean it. Rub too hard and it will put the sticky stuff onto the surface. You'll know when that happens. Flys will get stuck! The Tac cloth comes in white and yellow, which are both colors which show how much grit and dust has been collected from the supposedly clean surface. You would be amazed how much you will see. Do be sure not to buy a Tac cloth in the same color as your primer (or whatever you are applying paint over), or you won't see how successful you were with the initial cleaning.
Spraypainting is easy, so long as the technique is sound and the basics are understood. Having a lot of practice helps too. There is a huge number of hints and tips which can make the job sooooo much easier. You could fill books with em, which I recommend you buy if you want to excel. I have seen really professional results achieved by amateurs, and dreadful work done by professionals. Next time you are travelling in the roads, keep watch for cars that have panels which dont seem to be quite same color as the rest of the vehicle. These shoddy jobs are everywhere, and it amazes me how low the customers standards must be to accept the repair work.
Enjoy.
Tony