Basics

Powder coating should occur on all aluminum parts (6061 and 5052) that have been manufactured in our shop.

Cleaning the part

There are 3 things that we can do in the shop to clean an aluminum part:

• Scrubbing
• Wash it (depends on part)
• Acetone Wipe

When and why you should use these cleaning processes is detailed below.

Scrubbing

Whenever a Aluminum part is done being manufactured and getting ready for powder coating the first step is to scrub it.

Scrubbing makes the part as smooth as possible and gets rid of any imperfections so the powder coat can stick as well as possible.

To scrub take a green scouring pad and start scrubbing hard back and forth on the part in ONE direction( Make sure to put a good amount of pressure because other whys it won't really get into the aluminum.

You can also take an orbital sander and put a circular pad on it and do the same process. (Its much quicker)

• Make sure not to wear white pants or shirts
• Try not to breath in all of the aluminum and pad dust
• WASH your hands afterwards (Your hands will be covered in dust)

Washing your part

Whenever you are done scrubbing washing your part can help make sure its clean and let the acetone scrub go way quicker.

( If really backed up with parts not completely necessary to wash before Acetone)

For small parts just take a bunch of them and go into the marketing room sink and just give them a good rinse for about 30 sec each while scrubbing with a paper towel.

For large parts ask Ms. Rhea to let you through the Ag. room to use the hose out back. On the large parts make sure to wash and clean each side. Should take longer at like 4-5 min.

Make sure to dry your part thoroughly before Acetone scrubbing

Acetone Scrub

The sooner a part gets powder coated after manufacturing, the better due to aluminum oxidation.

Aluminum has a very high affinity to oxygen. When a new aluminum surface is exposed in the presence of air, it quickly develops a thin, hard film of aluminum oxide. This aluminum oxidation is both good and bad - good in that it provides a layer of protection against corrosion, but bad in that that layer can also provide resistance to powder bonding.

For powder coating, if an aluminum oxidation layer has built up on the part, we need to strip off this layer from the part before coating.

To do so, we can scrub the part down with acetone using shop towels to strip off the oxide. Fold the shop towels a couple times and thenput your hand with the towel onto the opeening of the acetone can and pour a little out. ( Just a quick tip to 90° and back)

A few reminders when cleaning a part with acetone:

• Make sure you are in a well ventilated area
• Use gloves!

Setup Checklist

• Confirm that there is nothing in the oven
• Turn on the oven to 400 degrees

Operation

Watch the following video in full (15 min):

Operation Checklist

• Turn on powder booth vent, and also the filter on top of the oven
• Verify powder container has about half a container of powder, and connect to the powder coat gun
• Attach the air compressor hose to "pressure chamber", and ensure the hose is not hanging from the device
• Attach and ground the part (copper wire to part if needed
• Spray the part while holding the trigger from a distance of 8 to 16 inches away
• Make sure part is fully and evenly coated
• Bake parts in the oven for 10 minutes after the oven reaches 400 degrees (ensure not to touch and knock paint off)

Advanced

Getting a uniform layer of powder onto a part can be a little difficult. We have the Powder Coat Pro gun, and therefore we have the ability to fine tune some settings to get a more perfect part.

Low Voltage Setting

The low voltage setting can be turned on by twisting the voltage knob to a lower voltage ~10. This is used for hard-to-get-to places such as holes, and corners. You should do your low voltage spots first.

High Voltage Setting

The high voltage setting can be turned on by twisting the voltage knob to a higher voltage ~40. This should be your default setting when using the powder coat gun. You can take the diffuser off while using the high voltage setting if you prefer - this will get you a narrower cone of powder spray.

Cleaning up

Once finished with your parts, or when you need to change colors, ensure you clean the booth and your gun.

• BEFORE cleaning your part or the booth, ensure the booth vent is on, and the voltage is turned off. 
• Ensure that your powder coating gun is in a secure spot, and will not fall over. 
• Get a large shop vacuum, and ensure the filter is mounted properly, and in good condition. 
• Use the vacuum on the tip of the powder coating gun.
• Take off the tip of the powder coating gun and using compressed air blow out the inside and outside of the gun.
• Start using the vacuum from the top of the booth to the bottom, ensure you vacuum up all powder. 
• Use compressed air to spray off the bar on the top of the booth. 
• Use compressed air to spray off the filter guard in the back along with the vacuum to ensure that it is fully cleaned and the powder does not spread. 
• Double check to make sure all powder is cleaned up, and that cleaning off the filter guard in the back did not spread further powder. 

Quiz

1. Some box tubing was just manufactured on the CNC mill and is covered with coolant. How should you clean your part before powder coating? (Choose all that apply)

• Wash the part off in the sink (using a strainer)
• Scrub the part down with steel wool and acetone
• Outgas for 20 minutes
• Nothing

2. A student just manually cut some axle stock on the band saw (no coolant was used). How should you clean your part before powder coating? (Choose all that apply)

• Wash the part off in the sink (using a strainer)
• Scrub the part down with steel wool and acetone
• Outgas for 20 minutes
• Nothing

3. The robot has been sitting in the shop all season, and we are about to attend an offseason event and want to make the robot look good. You disassemble the shooter, and want to powder coat the shooter side plates. How should you clean your part before powder coating? (Choose all that apply)

• Wash the part off in the sink (using a strainer)
• Scrub the part down with steel wool and acetone
• Outgas for 20 minutes
• Nothing

4. When cleaning up the powder coat oven, what should you NOT do? (Choose all that apply)

• Vacuum
• Brush and dust pan
• Air compressor
• Nothing

5. How long should you put your part in the oven for? (Choose all that apply)

• 10 minutes
• 20 minutes after the oven reaches 400 degrees
• 30 minutes
• 10 minutes after the oven reaches 400 degrees

6. What should you never do when powder coating? (Choose all that apply)

• Touch the emitter rod (tip of the gun)
• Touch a part while spraying with powder
• Touch the powder coat gun to the part when spraying with powder
• Spray the powder when the paint booth is off

7. How much powder should you put in the powder container of the gun? (Choose all that apply)

• 25% of the container
• 50% of the container
• 75% of the container
• Full

Skillset Verification

• Clean a part with an acetone scrub
• Turn on the oven
• Re-fill the powder container
• Hook up the air compressor line
• Turn on the paint booth and the fan above oven
• Coat a part
• Place a part in the oven SAFELY
• Clean the booth and gun completely and safely

Dwyer MK2 (Airflow measuring device):

The Dwyer Mk.II is a device mounted on the side of the powder coating hood used to measure airflow from the powder booth vent. 

Ensure that when the hood is on, the red gage fluid reads 0 inches of water column. If not, using the bottom left knob adjust until it reads 0. If it is unable to change, find a mentor for assistance. 

Two-Tone Powder coat:

Special still in progress