Written By Steven Craig
ARTIST PROFILE
STEVEN CRAIG
DATA
Steven Craig is the owner and head painter of SKC CUSTOMZ in Lake Havasu City, AZ. In the past Steven has won the House of Kolor Prestigious Painter Award and was a 1st Place winner of Dupont's Hot Hues Awards. He most recently was awarded the Matrix System's FX Grand Prize Award. Steve paints a wide range
of jobs from guitars to large off shore boats. Visit his web site at
Airbrush
:
Iwata HP-BH, Custom Micron B
Spray Guns:
Iwata LPH400 ,Iwata LPH300, Iwata LPH-80
Paint Media:
PPG, Xotic Colours, Dupont and Matrix Systems
Surface Media:
Everything I can get paint to stick to.
Masking
:
R-Tape and 3M Masking Tapes
Projector:
Artograph
Lighting
: Natural and Florescent. Spray-Line and Spray King Paint Booths
Steven is a Certified Paint Technician for both PPG and Dupont Industries.
"Spray Gun Cleaning
Custom Painting is an industry where the right tool makes all the difference in the final product. Cheap throw away spray guns can be purchased but, you'd be fighting the painting process more than it's worth. The spray guns today are extremely precise pieces of equipment. Professional painters will spend thousands of dollars on their arsenal of spray guns.
Quality spray gun equipment is very expensive and you want to maintain them to insure that they will continue operating at peak performance. Get a good gun cleaning kit. There are several available on the market ranging from $10.00 to $35.00. Pictured here is a kit available from Astro Pneumatic and comes with basically everything needed to properly clean a spray gun.
Before doing anything, make sure that you wear the proper safety gear. Rubber gloves are a must! Cleaning solvents will be absorbed through the skin and can lead to serious heath problems. I know it's hard to do, but I recommend that you wear a respirator and eye protection when cleaning a spray gun. The vapors from the solvents can also cause damage if inhaled or absorbed through your eyes.
Start by what is called "Perking". This technique was developed by Sharpe for use with gravity guns to eliminate the need to tear down most of the time. Here's how perking works. You dump out whatever coating is in the gun. You add solvent, then loosen the air cap from the gun so that's is just about hanging off the gun. Turn down the air pressure to about 10 PSI and pull the trigger. Cover the top of the gravity cup with a rag. The gun will now percolate like an old style coffee pot and clean itself very nicely. Continue this for about 30 seconds. Dump out the solvent, wipe the gun off and you're done.
I'll use the "Perking" method for quick color changes, but it's not enough to maintain the newer precision spray guns. The slightest particle or paint build up will change the atomization or spray pattern. People shooting solid colors may not notice a difference in paint delivery but, custom painters will see it immediately when shooting Candies. I tear all my guns down to what you will be reading here after each work day. Start by removing the Air Cap (#1 see parts list below).
Remove the Fluid Adjustment Guide Set (#11). Pull out the Fluid Needle Spring (#10), which is located at the back of the spray gun. Pay attension when removing the needle spring, they have been known to shoot out of the gun if the spring tension has been loaded.
Here is a close-up of the Fluid Nozzle being removed. These parts are machined to provide a precision instrument, meaning the threads have very little tolerance. Do not force them to loosen up for removal or the threads may be stripped and ruin the equipment.
Slide the Fluid needle out. Pull stright back and use precaution as to not bend the needle tip.
There are three sizes of fluid tube brushes in the cleaning kit. Dip the largest of the three brushes in cleaning solvent, insert into the fluid nozzle cavity and the fluid nipple (where cup screws in). Twist the brush back and forth the remove any paint particles that are still inside the spray gun.
All spray guns come with a tool that is specifically designed to remove that spray gun parts. Do not use any other tools to remove these parts. The metal of the spray gun is soft and by using tools like a Cresent wrench you may damage the parts. Now, remove the Fluid Nozzle.
Have a container ready that contains cleaning solvent. For automotive grade paints I prefer to use 100%v Virgin Solvent (Lacquer Thinner). Place all the parts that have been removed in the solvent and let them soak for a few minutes. This will loosen up paint residue that will make cleaning easier.
This is a close up showing the inside of the fluid nipple (#4-2). If any paint remains in these cavities, they may and most likely will, break loose during a future paint session. A speck of residue that may be still in the gun may alter the spray guns performance. A black particle of paint that may have been lodged in the gun would not look to pretty if if broke lose when you were spraying a light color , like yellow.
The cleaning kit comes with a Body Cleaning Brush (wood handle), dip the brush in solvent and remove all the paint and over-spray on the body of the spray gun. Pay close attention to cleaning all the threaded areas.
Use a high pressure air nozzle and force air through the fluid nipple. By doing so, this will remove any paint debris lodged deep inside the spray gun that the cleaning brushes could not reach.
Maintaining Your Equipment
It is important to clean every part of the spray gun, but one of the most crucial is the air cap. The Air Cap (#1) is the leading controller of the spray pattern. The air cap is even more temperamental with the Iwata LPH series spray guns. Every air passage must be free of debris. Use the body cleaning brush to break up and remove any paint, pay close attention to the outer edges of the air passages.
Thoroughly clean the inside of the air cap. Iwatas have a rubber seal on the inside of the air cap, inspect the seal and make sure there is no paint build up on it. If paint film is developes on the seal, the air cap won't seat correctly against the body and it will cause an air leak that in turn will force air up into the paint cup.
Double check the air cap for obstructions by holding it up to a light and inspect the air passages. Here you can see a small amount of paint debris lodged in the tiny air hole. This will create a disruption in air delivery and alter the spray pattern.
To remove any paint build up in the small air holes, insert the Straight Line Wire tool into the hole and push through the hole. The wire has a slight taper to it and will remove the paint build-up and restore the proper radius of the passage. Do not force the wire through the hole once it's tight. The wire will get stuck in the hole or change it's diameter.
This is a trick I learned from my Iwata Rep. About six months after I started using my Iwata LPH-300 I started seeing a drastic change in the spray pattern. It was more evident when spraying candy colors. I broke the spray gun down several times to clean it, yet the spray pattern still wasn't right. There was a small imperfection at the air cap that distorted the pattern. He showed me a trick by taking a soft lead pencil and shoving it through the center of the air cap and twisting it. This removed the unseen paint build up and corrected the problem.
Be careful not to drop the Fluid Nozzle (#2-1) when cleaning it. The nozzle can be easily damaged and is an expensive part to replace. Start by cleaning the outside with the nylon bristle brush. Normally this doesn't need to be done, but if there are any obstructions clean the air passages in the fluid nozzle by inserting the wooden picks through the holes to remove any debris.
Insert the medium sized fluid tube brush into the back side of the fluid nozzle and twist while moving up and down. Dip the brush in solvent and repeat until any paint inside has been removed. Flush the fluid nozzle with clean solvent to rinse out the inside.
Take the body brush and scrub the the fluid needle with solvent. Make sure any and all dried paint material is removed. The needle needs to properly seat to the internal packing and or o-rings.
Insert the medium sized fluid tube brush into the back side of the fluid nozzle and twist while moving up and down. Dip the brush in solvent and repeat until any paint inside has been removed. Flush the fluid nozzle with clean solvent to rinse out the inside.
Reinstall the fluid nozzle. When tightening, just snug it up to the body. Do not over tighten, this is not like tightening a bolt. There is very little tolerance between the body and the fluid nozzle. Over-tightening may damage the internal components or strip the threads.
The needle needs to be lubricated before inserting it back into the spray gun. There are several lubricants made specifically for automotive spray guns that do not contain silicone. Silicone is not compatable with urethane paints and when mixed together, it will create fish-eyes. Apply a thin coat of lubricant to the area of the needle that seats with the o-rings or Teflon packing. The entire needle does not need lubricant. Starting about 1/2" from the tip add lubricant to about the half way point.
Solvents are very harsh on Teflon packing and o-rings. If lubricant is not applied to the needle, the seals will dry out and swell up. This will cause the needle to stick in the spray gun. Once the seals go bad, the gun will need to be rebuilt.
Push the needle back into the spray gun, pull it back and forth to lubricate the seals before seating it with the fluid nozzle. It wouldn't hurt to add a little lubricant to the air valve spring before reinstalling.
Once the spray gun is completely reassembled, take a clean cloth with solvent on it and wipe down the entire body of the spray gun to remove any remaing over-spray.
There you have it! A well maintained piece of equipment. These spray guns are expensive and the most important tool that any custom painter uses. Take care of them and they will continue to make you good money for many years.
