Basics

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

Cleaning the part

There are 2 things that we can do in the shop to clean an aluminum part:

• Acetone Scrub
• Outgassing

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

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 steel wool or a finishing pad to strip off the oxide. A few reminders when cleaning a part with acetone:

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

Outgassing

Outgassing is the process of removing embedded or trapped gasses on the faces of your aluminum part. It sounds more complicated than it actually is - in reality, all we are doing is baking the part.

The reason outgassing is important is because most of our parts are coated with coolant due to machining the part on the router or the mill. This coolant or oil can get embedded into the part and add irregularities into your powder coat layer.

To outgas, we can place the part in the oven at 400 degrees and bake for 20 minutes before powder coating to release any gasses trapped in by the coolant that coated the part during manufacturing.

Setup Checklist

• Confirm that there is nothing in the oven
• Move the internal oven rack to a place where you can easily reach it when hot
• Turn on the oven to 400 degrees

Operation

Watch the following video in full (15 min):

Operation Checklist

• Verify powder container has about half a container of powder, and connect to the powder coat gun
• Attach the air compressor hose
• Attach the ground cable
• Attach and ground the part
• Spray the part while holding the activation button from a distance of 8 to 16 inches away
• Bake in the oven for 20 minutes after the oven reaches 400 degrees

Advanced

Getting a uniform layer of powder onto a part can be a little difficult. We have the Eastwood dual voltage 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 setting the switch to setting #1. This is used for hard-to-get-to places such as holes, and 90 degree corners. The diffuser is required when using the low voltage setting. You should do your low voltage spots first.

High Voltage Setting

The high voltage setting can be turned on by setting the switch to setting #2. 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.

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)

• 20 minutes
• 20 minutes after the oven reaches 400 degrees
• 30 minutes
• 30 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
• Clean a part with outgassing
• Turn on the oven
• Hook up the ground cable
• Re-fill the powder container
• Hook up the air compressor line
• Turn on the paint booth
• Coat a part
• Place a part in the oven SAFELY

Dwyer MK2:

Flow measuring device, uses gage fluid, this will be updated more -------------------------------------------------------------------------