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Cleaning the part

There are 2 3 things that we can do in the shop to clean an aluminum part:

• Acetone Scrub
• Outgassing

• 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.

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To do so, we can scrub the part down with acetone using steel wool or a finishing pad 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!

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

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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
•  Attach the ground cable
• 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 activation button trigger from a distance of 8 to 16 inches away
•  Make sure part is fully and evenly coated
•  Bake parts in the oven for 20 10 minutes after the oven reaches 400 degrees (ensure not to touch and knock paint off)

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

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The low voltage setting can be turned on by setting twisting the switch to setting #1voltage knob to a lower voltage ~10. 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.

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

Thick Powder coat

When powder coat is applied too much, it often appears similar to the first 2 images below, a dimpled texture, or a dripping texture. This is caused when the coating of powder is too thick, and when it goes into the oven to cure, the powder melts and starts either dripping or creating a dimple texture due to uneven curing. The 3rd image is a example of a use case of low voltage, where the inside of the corner does not fully coat, so low voltage is needed.

(CWFishing is the source of the image, click on the image for a link to the source)

Image Added

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)

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

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

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•  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 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