I've had decent luck just scuffing the existing powder coat with a couple (Course & Medium-green) Scotch-Brite pads... The Course is good for feathering any chips out and heavy funk. The Medium is good for knocking any remaining funk off, and then the gloss off the rest. I use lots of clean/soapy water and generally cut the pads into useful-sized chunks... and then when they get nasty, toss the used chunks out and refresh the water/soap. Towards the end of this process, the intent should be having a smoothish and clean surface (substrate if you must) with some 'tooth' to it... microscopic peaks & valleys that the new finish can adhere to better than a Baby's Arse Smooth surface.
I chase my victims down with rubbing alky to remove any oily residue the scrubbing misses, then shoot em with "whatever" brand spray paint I can easily lay my hands on at the time. Gloss Black, Satin Black, or Flat Black. My next pair may get shot with EZ-Slide Graphite-Based Coating (sort of an Almost Black) as that may help shed mud more effectively, and reduce the friction of the springs as they compress and extend.
Most all spray can paint is oil-based and comes in a few flavors... The most common will be Acrylic Enamel, followed by Lacquer, then (Poly)Urethane Enamel. There are also Epoxy appliance paints, and Tree-Hugger Approved Water-Based aerosols out there... You'll spot the latter two 'exotic' flavors by their Higher-Than-Frugal price tag. I favor the $3/can stuff (‘American Traditions’ Acrylic Enamel at Lowe’s) as there is a difference between it and the $0.99/can Wally-Brand. Enough difference to matter on chassis bits? Your junk, your call. Be advised that Lacquer tends to have a fairly aggressive solvent mixture... It can eat Enamel -especially new spray can enamel- for lunch and leave a strange-looking finish. If this somehow happens, suck it up, remove it, and start over. Enamel over existing Lacquer isn't usually cause for any new problems.
Some More Tips:
Read the directions (not while shaking the can.) Lots of thought and careful consideration went into those directions, and by-golly you Are At Your Own Peril if you don't! We're not mixing up frozen orange juice concentrate & water here, Martha, we're setting off to do Things With Combustible Vapors! Contents Under Pressure! Slippery When Wet! May Cause Brain Damage! It Is A Violation Of Federal Laws To Use Product In Manner Inconsistent With Its Labeling! Holy Crap! We're wandering a narrow path between Hiroshima, Alcatraz, and One Flew Over The Cuckoos Nest here! Serious Business Indeed! In other words, put a clean diaper on, wipe the boogers & nose hairs off your Poindexter spectacles, and focus on what you are fixin to do.
Shake the can vigorously and continuously. This isn't skipping third-period study hall above the girls’ locker room we're talking about, this is Manly Work! Unlike similar endeavors, keep shaking long after the balls start rattling. Feel free to switch hands. Think chemistry, not biology, and most aspiring painters should get through this part OK.
Don’t spray it in your eyes ears, nose, or other orifices... and smoking is optional, but discouraged. There is a handy arrow on the top of the nozzle button, which corresponds with a small circle- usually of contrasting color- on the discharge side. (The paint comes out the center of the small circle!) If these indicators all fail, Hitch your chaps up, Cowboy... affix a proper Steely-Eyed Squint, aim that cannon down range, brace for impact, and pull that trigger. You have an approx. 25% chance of hosing yourself, but if the arrow & hole in front doesn’t point up anything obvious, this method is all you got.
Now you are Armed & Dangerous... your balls are shaken and you figured out which is the business end. The green light is on and you are standing in the door, over the drop-zone... Geronimo!
Spray the victim with lightish even coats, waiting a bit between coats to let the propellant/solvent evaporate and the finish set up. Odd Shaped and Multi- Part Victims such as coil springs, control arms etc. may require shooting from different positions to get complete coverage per coat. Unless you need the exercise, or want to drill that hole to China your Momma warned you about, don’t circumnavigate the part like a horse on a tether... (If a horse had a decent brain, it would spend most of it's time chewing on the rope in secret, and then once it's human set it loose to run those gawdawful circles again, it would break loose, then gallop over and kick the human upside the head. Then repeatedly stomp him or her in the tenderish parts... since it’s decent brain would remember the last whipping it got.) Apply even coats until the desired effect is achieved. Shoot all the spots you can reach from one position, THEN walk around and shoot the far sides. You do have a better than decent brain, yes? Alternatively, hang the parts so that a Genuine Helper Elf can slowly rotate the victim...Allowing you, O Skilled and Ingenious One, to just stand there and spray like a tomcat on porch night.
If one is using Gloss, they should up the thickness of the last couple coats so that the finish spreads out some and dries shiny. If one is using flat, flat is what they should get. Satin is in between. EZ-Slide Graphite is Almost Black…not glossy nor flat. Kinda like satin. Don't run the stuff... Drips, Sags & Runs means one is holding the can too close to the victim, and that they suck at the painting. Orange Peel is from holding the can too far away from the victim, and that you suck at the painting. If you suck at the painting, and care about the visual results... Wait awhile for the paint to cure, then sand out the boo-boo with Wet/Dry sandpaper in about 320-400 grit (or a clean-piece not used in de-funk/greasy prep- Scotch Brite pad) Lots of soapy water, degrease with Rub Alky, then respray at least one more coat to get the desired effect. Consider that you aren't painting the Sistine Chapel here, Rembrandt... or putting your priceless junk up for auction on Barrett-Jackson. You are painting chassis bits for a Jeep.
Just when you think it's safe to touch the stuff is just the right time for you to grab it and leave fingerprints. This is a good way to mark your parts in case the rig gets stolen and parted out... Tell the cops that you have a cards worth of fingerprints on your 'custom-painted' parts and they will #1 Laugh at you for Sucking At The Painting, and #2 Appreciate The Help. If you were rollin wit Inspector McGruff you would have stuck a few hairs in the wet paint along with the prints. DNA is what they call it. Yours and yours alone... unless you are a twin. And if you have a twin sibling that steals, or buys your stolen Jeep Junk, well, that is beyond the scope of this post.
After you are through painting, you can use up the remainder of the can in various ways. (No, it won't keep till the next project, but if you have the room, you can keep it around just to aggravate yourself later.) You didn't wear a mask, did you? You did? Dammit Roosevelt, go put your pocket protector in, and carry that stuff to the local Fire Department. I'll bet they'll love to see you coming up the drive. Place the spent cans in a blast-proof travel container too, just for piece of mind, and drive extra slow with your 4-way flashers lit just to let everyone else know You Are Up To Serious Business... to be specific, Hazardous Material Disposal. Wear your safety goggles.
You say you didn't wear a mask? Excellent! That opens up a Whole New World of recreational mischief. :viking: Several avenues of amusement await.
Remove the nozzle and replace it with one from a different aerosol can. Just like belly buttons, there are two types of nozzles... Innies and Outies. These are not interchangeable... stick with what you have in the arsenal. Carb or Brake Cleaner nozzles shoot a narrow stream of paint pretty far, where the OEM nozzles are jetted to atomize (expel into a fine mist) the contents. Using gas torch tip cleaners or very small drill bits, one can fine tune the nozzle output to match the intent of the mission... One can use the remainder of the product as-is, or for more excitement, add an external source of combustion.
Other more advanced methods for disposal exist, but until the reader masters Not Sucking At The Painting... they may be best left for later.
:wave:
