[size=12pt]Painting 201[/size]
For these purposes we are using a two part paint and then a clear. We will be using a HPLV (high pressure low volume) air gun.
I'm going to start with after you have prepped, primed, sanded the piece to paint. At this time you should lightly wipe the piece down with a clean rag and a little thinner (non-petrol type aka not mineral spirits). Be sure not to wipe too hard or have the rag too wet because if you didn't use a two part primer it may wipe it off and thats never good so be careful. Test a small area first. Next, time to mix the paint, follow the directions that come with that paint as it differs from brand to brand (Awlgrip is a 1:1:1 paint:thinner:reducer[catalyst] and International is 6:1 paint:catalyst). Some paints require you to let the paint sit after you mix it up for 20 mins or so, use this time to get everything ready to spray.
Pre-Paint
When the compressor is filled up you should drain whatever condensation is in the tank because water droplets under paint are not good. Next you can unwind your hose if not already done, untwist it and get all of the assholes(kinks) in the line, you don’t want to have the hose get hung up during a spray and it causes the gun to stop or move close and you have a run on your hands. Not cool either. Another thing, if you invested in one(and you should if you are considering painting more) hook up your water separator/air filter to the compressor then the hose, once again water and paint aren't friends in this process this isn't latex paint. Next, put some thinner in your gun hopper, swish it around, and spray it out (away from your painting piece) turn your nozzles(paint adjustment and tip setting[fan/spot]) to make sure everything is working. Also, I like to use a piece of plywood to practice on before shooting, use the thinner to get your fan setting right(fan for flatter surfaces, spot for tubes, frames, tight spots) and get everything in a good "ball park" area, don't want to piss away paint adjusting your gun. Lastly, and I could have missed something in your case so this is flexible, you need to get a tack cloth (get them from any hardware, Lowes, etc.) and wipe the parts down to remove any dust or rag particles that may have settled on it since you wiped it down.
Paint mixing
From here you are ready to start spraying. First, give your paint a good stir before you go to pour it in the gun, some metallic paints will settle a little. Use a paint strainer when pouring from the mixing cup to the gun hopper to prevent large particles that may have gotten in there. You don't want that because it could clog the tip of the gun and cause it to squirt instead of spray and that's about as bad as a run...or water for that matter, not cool! When you are all loaded up, hook up your hose and since we are using a HPLV we need to set the compressor to 40-45psi sustained. I say sustained because when you pull that trigger I shouldn’t drop below what its set at so if it does, adjust it higher(might want to test this with and empty gun). Now go back to that trusty plywood and give your paint a test spray and make sure everything is kosher. Ok? It’s time for the next step.
Paint baby, paint!
For education purposes we will be painting a big flat sheet. When you are painting something, the distance from the gun to the sheet will vary depending on what you have your paint output set at, this you will have to learn with practice, but you should start by erring on the side of not enough paint coming out rather than too much. Too much paint too fast=runs, Runs=bad. Since this is a flat surface, we will set the gun tip to vertical fan. Now I usually have the gun around 8-10 inches from the sheet, once again if you are starting off err on the farther side to prevent runs. You want to keep this distance uniform, so if you are painting a curved surface like a tank you need to compensate for the curving of the tank and keep the distance right. Practice with the gun, just don’t spray until you have it down. Ok, now that we have a distance FROM the sheet we need to get the angle TO the sheet down. You want a perpendicular angle from every angle you can possible keep. So this means when you spray from left to right, you should stand in the middle of the section you are painting, and hold the gun 90 degrees both directions to the sheet. So when you go from left to right you should bend your wrist to compensate for the angle change when moving your arm. You don’t want to move your body because it’s not a smooth movement. Alright, now that you have the distance and angle methods down let’s move on to spray pattern. When you are spraying you always want to overlap what you just painted. So let’s say the gun sprays a 10 inch path, you paint your first line on the sheet, 10 inches, and your next line below should only cover 5 inches of unpainted sheet while covering 5 inches of what you just painted above. This ensures you have uniform coverage and no dry spots. You can follow the lines of the piece if you want just remember to paint with corn rows in mind, each path next to the other so you don’t miss anything. Right! So now we have distance, angle, and pattern covered (pun intended) we can go over Technique! Alrighty, now this is where practice comes in so practice with that thinner beforehand. Ok so you have this sheet to paint, you don’t want to pull the trigger on the edge of the sheet then start moving to the side. This has a higher chance of causing runs. What you should do instead is hold the gun (left to right here) hold the gun farther to the left than the piece, start moving your arm to the right while simultaneously pulling the trigger, this way the your arm is already moving (at the correct distance and angle right?) and the paint is already spraying when you GET to the sheet. And when you get to the other side of the sheet you pass the edge up THEN let go of the trigger, on the return swing (right to left) you do the same thing move, trigger, then get to the edge(remember overlap!) . If you have to stop mid spray for any reason, don’t just stop your arm and the gun at the same time, stop the gun first then you can stop your arm. You want the paint to consistently mist onto the sheet. You continue this until it is covered. Once you get a hang of it, it will be like second nature to you. Another tip while painting, hold your hose in your free hand. This will keep the hose’s location in your mind while you paint so you don’t, a) trip on it b) have it swing on to the piece being painted. Also, keep a little slack from your hand holding the hose to the gun, that way if the hose gets hung up you have a little time to react before the gun gets jerked(aka let go of the trigger in motion). By now you should be painting like a modern age Van Gough with a gun!
Coats, for pretty ladies and paint jobs
The first coat will be a little on the dry side because it’s not what is making it shine, you are just laying down a base layer. So this first coat will be light and probably won’t look shiny, but don’t fret my young grasshoppers! It will in due time… When you finish the first coat you should wait until the paint is tacky to the touch, when you touch it(and by it I mean not the actual paint, touch some tape or paper that has been painted!) you shouldn’t have any paint sticking to your finger/glove but it is still sticky. When its good and tacky you can start on your next coat. This will be a little more wet and will start to shine and reflect. Be mindful of your distance, angle, and technique as the more coats you put on the “heavier” the paint will be. Any mess up of either of those and you could put too much pain in an area and cause a run, and trust me, if you get this far and you get a run you will want to punch someone or something. So be patient, the gloss will come with coats. After each coat make sure the previous coat is tacky before spraying again. Each coat after this one will be wet coats, as in it should be shiny where you have sprayed and you shouldn't have dry, matte looking spots. But don’t go too wet or you will run, it’s a fine line, so don’t get greedy ya filthy animal! I recommend only 3 good coats of your color, if you do it right you don’t need any more as its just unnecessary. A little inside trick of the trade I’ll share with you that was passed on to me from my dad, Ronnie Sr., is mixing the clear with the paint. Let’s say we did our 3 coats of color and now we are ready for clear (mix the clear according to directions, also we are assuming the clear is the same type and brand as the color paint). Coat 4 will be a mixture of clear AND color, let’s say a 50/50 mix. Do your coat like the previous coats. The next coat, 5, will be a mix of 75/25 clear to paint, spray it. And the last coat will be just clear. This gives it a deep, wet effect to the paint which is always nice. Alright so now you are set and should by this time have a part that is painted so well it makes women flock like the salmon of Capistrano.
Clean up
Do this away from the painted piece, please! Dumb the remaining paint/clear out and pour that thinner you saved from earlier into the hopper, swish it around really well and spray it all out of the gun until its empty. Then pour some new thinner in there and repeat until you are spraying clean thinner out the gun(note Please do this away from fire, etc.) next take the gun apart(at least the tip) and wipe the gun down with thinner, reassemble and store. Clean up your mess with the paint, filters, hose, compressor, beer cans, etc. The next day, peel all the tape away and let the piece sit for a solid week to cure.
Do NOTS:
- Spray at night, the dew/humid air will make the paint blush and when that happens you might as well get the stripper or sandpaper out cause buffing wont help. (this obviously excludes those fancy people with climate controlled paint booths)
- Spray in the evening (see above)
- Spray in a windy area or on a windy day(if you are painting outside), you will have dust,pollen, bugs etc on and in the paint which will suck because you spent a lot of time on this.
- Sneeze on the wet paint
- Paint on a rainy day, moisture isn't good with curing paint, blushing will happen(excludes booths)
When I get time I'll try to add pictures to this.. Hope this helps you guys and I am no expert but I am experienced so this is what I personally do. Enjoy and go paint!
