How to Clean Your CNC Machine

You need to sell it because it's just sitting there taking up valuable space. But every time you look at your worn and weathered CNC machine, the thought of transforming it into something that looks worth buying fills you with dread. If cleaning's not your jam, that's okay, because you're about to discover a tried and true process to make your CNC machine market-worthy now.
The Key
We've discovered the key is to not put a lot of money or time getting older machines rigged in and cleaned out because they don't sell for a whole lot. I'm going to share some quick tips to make your CNC mill look great by applying our cost-effective, efficient, and safe process to get it ready for market, so that you can sell it quickly.
What You Need
These are the materials we actually use to transform a decades-old CNC machine to look brand-new.

1. Zep Industrial Cleaner & Degreaser — Also referred to as degreaser. This is item is key. It works really well, and you’ll use it several times throughout the process. Follow instructions to dilute and make solution on a spray bottle.
2. Goo Gone Pro-Power or Goof Off or Rubbing Alcohol-– If you run into some really tough stuff on the machine, like paint that’s been sitting on there for years. Rubbing alcohol works as well, but we don’t use it that often.
3. Terry Cloth Towels, otherwise known as cloths or rags.
4. 3M Rubbing Compound (Industrial Grade) or Meguiar’s Ultra-Cut Compound — You can buy this right off the shelf at places like Walmart or Auto Zone.
5. 10-inch Buffing Wheel — we avoid repainting as much as possible, just touchup when necessary.
6. Water in a Spray Bottle
7. White Diamond Metal Polish — Great for polishing up metal. We use this on tooling as well. It’s a little expensive, but goes a long way and lasts a good while.8. WD-40 — We use it in a spray bottle.
9. Scotch Brite Pads, industrial strength. You can get it at Home Depot or pretty much anywhere; we buy ours at Sam’s and get the bulk version. You’ll use this on the bare metal, like the way covers and the table.
10. Novus 3-2-1 System — Available on Amazon. For the windows, if they’re not really cracked or gouged too badly. This takes out years of little nicks from the chips hitting the window.
11. Touchup Paint/Spray Paint — Again, we try to stay away from it as much as possible, but every used machine has got some nicks in the paint, so we like to touch them up and make them look good, but at the end of the day, try to keep it all original.

What YOU Need

1. Toothbrush
2. Wire Keycap Puller (optional)
3. New Manufacturer Sticker (optional)
4. Credit Card or Putty Knife (optional)
5. Leveler (optional)

Pre-Cleaning Inspection
Outside Machine
Before you start the cleaning process, you’ll want to take a closer look at what years and years of use have done to your machine. In addition to layers of dirt, grime, and fingerprints, look for tape residue, indications of permanent marker, and inspect the manufacturer tag or sticker to look for peeling and determine if it needs to be replaced. Then, check out the stainless-steel plate to note how grungy, dull, and grimy it may be. Next, take a look at the doors. Make sure they’re rolling smoothly and check out the plastic. If the doors have cracks and gouges, you'll need to replace them, but the process is very basic. The 4’x8′ sheet is1/4″ or 3/8″ thick, depending on the model. You can get them at Home Depot and they're about $170. Look at the controls, dials, and keypads which are typically riddled with dirt and grime from years and years of use. Note if any keys are missing and check to see if any of them stick. Now, check out the rest of the outside of the machine, look for smudges, black marks, and tape residue.
Inside Machine
The inside of the machine is going to be just as dirty and grimy as the outside and may have some chipped paint. You'll want to look at the spindle and note if there's corrosion. Look for major drill marks or scarring on the table.
On some older machines, the coolant nozzles are hodge-podged together and mismatched. In that case, I suggest you get new ones. They're inexpensive and you can Amazon Prime a set of four for under $20, it makes the machine look so much better.
Cleaning the Outside

Step 1: Degrease and Clean Entire Machine
What you'll need:
1. Zep Industrial Cleaner & Degreaser
2. Goo Gone or Goof Off
3. Terry Cloth Towel
Apply the degreaser to the whole machine, top to bottom, sides, and back, and degrease it. Most of the dirt should come off, but tape residue and dirt in nooks and crannies, and writing from markers may remain and that's fine because you'll be getting that off later. Don't forget to do the sides as well (where the door frames are).
To remove tape residue, lettering from a marker, black marks, or stubborn smudges, use Goo Gone or Goof Off.

Step 2: Deep-Clean Entire Machine
What you'll need:
1. 3M Rubbing Compound (Industrial Grade) or Meguiar's Ultra-Cut Compound
2. 10-inch Buffing Wheel
3. Water in a Spray Bottle
4. Terry Cloth Towel
5. Novus 3-2-1 System
This step is satisfying because you're going to get the ground-in dirt and remaining marker off the machine, and you'll get a uniformly clean appearance.
You'll be using the 3M industrial-grade rubbing compound and a buffer. Take a little bit of the rubbing compound and apply it to the pad. You'll want to rub it around the surface at first, so it doesn't sling everywhere. One of our secrets is we use water to help the compound move nice and freely over the paint and prevents it from drying out quickly. Spray the area you want to work on with water. When you're buffing, be careful around the labels, you can touch on them, but if they're starting to peel, you may end up ripping them. You’ll want to finesse your buffer to get around them as much as possible and get the spaces inside and in-between the letters. Any time somebody uses a marker, it takes extra effort, so add more compound if you still need to get the marker off.
Do the doorframes next and remember to spray your water first. At this point, there should be enough compound still on the pad to finish those out.
Wipe down the residual compound to get it off. Spray your water on the machine and wipe with cloth.
Compound the sides and back of machine.
Next, use the Novus 3-2-1 System to clean your windows to get them back to their original state.

Step 3: Polish
What you'll need:
1. 10-inch Buffing Wheel
2. White Diamond Metal Polish
3. Water in a Spray Bottle
4. Terry Cloth Towel
5. WD-40 in a Spray Bottle
6. Scotch-Brite Pad
Polishing is vital to get that machine's appearance back to its original state.
Take your White Diamond Metal Polish and spread it around first. You'll spray your water first like you did when buffing with the compound; this makes it go a lot further. Don't forget to get the sides where the doors are and the door frames.
Polish the sides and back of machine.
Next, you'll shine up the stainless-steel using the WD-40 in a spray bottle and a Scotch-Brite pad. Spray your WD-40 on the stainless-steel and make sure you wipe with the grain. This is very important because if you go against it, it will highlight the scratches. Make sure you get the grime off around the bolts and off the bar under the doors. Use your cloth and wipe it down.

Step 4: Clean the Control
What you'll need:
1. Zep Industrial Cleaner & Degreaser
2. Terry Cloth Towel
3. Water in a Spray Bottle
4. Toothbrush
5. Wire Keycap Puller (optional)
Now, that you've got the entire outside clean and shiny, the control looks dirtier than ever.
Keypad
Spray the degreaser on your cloth, DO NOT spray directly on the controls itself, spray some on the cloth and let it soak in. Gently start wiping across the keys, making sure not to push them in hard. Use short, quick strokes on the surface of the keys. Let the degreaser sit there and it will start to work for you. Work a corner of the cloth to get up on top of the keys as well. To really get back under the ledge of the keys, you will need a wire keycap-puller to actually pop the keys out. But this is a quick, easy way to get most of the area of the keys cleaned up.
Dials
Turn to the dials with your degreaser-soaked cloth and clean and work on them to make that silver shine. Be sure to get back behind the emergency button to get that bright yellow popping again. Wipe the screen down thoroughly, getting up and around the edges as well. Turn to the hand dial. You will see a lot of dirt and grime wedged up underneath there and in the crevice around the edge of the dial. It's nice if you can roll the dial into the rag, it'll help clean it up. You may be taking off decades worth of usage, so expect to use some elbow grease to clean it up.
Work your way down to the green and red buttons where you'll significant dirt and grime, especially along the edges and in the crevices.
Along the edges of the panel, you can take your thumb with the cloth and run it alongside the length of the edge to clean up all that grime. Next, clean the sides of the control unit — you can spray the degreaser directly on the sides — don't forget the edges.
Detail Keypad
Use a good old-fashioned toothbrush for the hard-to-reach places. Spray the degreaser right on the toothbrush (don't spray directly on the controls), shake it to get the excess off. Brush on top of the keys and in-between the keys, being careful not to push the degreaser back behind the keys, it'll only create more problems for you. Be careful when you do this. I recommend brushing up and down versus going into the control, that way you're putting pressure on the top of the buttons or on the sides. Use your cloth to frequently wipe off the degreaser residue to prevent it getting in the back of the keypad. You'll also want to clean your brush off as you continue working on the keys. Using the degreaser is a little risky, but it comes down to how much time you have and what works best for you.
Detail Dials
Use the toothbrush in the same way to get to the hard-to-reach areas on the dials, especially on the back side like where the Start button is. You can actually get in the face there, getting that little crevice around the face of the button. Do the same thing on the Stop button. Wipe them off with your cloth and you'll see they look like brand-new. Repeat this process for the handwheel and the silver buttons in the hard-to-reach places where the cloth can't reach. On the red Stop button, get all of the dirt out of those arrows and you'll get the original bright white and shiny red colors.
Cleaning Keypad via Keycap Puller
What you'll need:
1. Wire Keycap Puller
2. Smart Phone or Camera
3. Diluted Zep Industrial Cleaner & Degreaser in Spray Bottle or in a Bucket
4. Terry Cloth Towel

If you really want to get your keys looking good and you don't want to risk getting the degreaser on the back board behind the keys, you'll want to use a wire keycap puller. They're fairly inexpensive (under $10) and available on Amazon. You can clean one key at a time (Option 1) or clean them in a bucket all at once (Option 2).
Option 1: This is a pretty simple device that you'll slip around the key cap and gently pop it out. You'll see years of dirt and grime on it. Take your degreaser-soaked cloth and gently clean all four sides and the front. Gently stick it in its proper spot.
Option 2: Take a picture of the keypad panel, so you know where everything goes back. Using the wire keycap puller, pop all the keys out and soak them in your degreaser in a small bucket. Wipe them clean and dry and then gently stick them back in their proper place.

Do a final wipe-down of the entire control. Cleaning the Inside
What you'll need:
1. Zep Industrial Cleaner & Degreaser
2. WD-40 in Spray Bottle
3. Scotch Brite Pad
4. Touch-up/Spray Paint
5. Terry Cloth Towel
6. New Manufacturer Sticker
7. Credit Card or Putty Knife
8. Water in Spray Bottle
9. Leveler
Use your degreaser and clean all surfaces, including the coolant nozzles if you're not replacing them. If you're replacing the coolant nozzles, pop them off and spray a little bit of WD-40 chrome and metal, and wipe with Scotch Brite pad. As well as shining it up, this will get the corrosion off, however, you want to be careful, especially with the chrome pieces, because they can definitely scratch. Wipe off with cloth.
Turning to the spindle, use your Scotch-Brite pad you want to wipe with the grain, so you're going to go horizontally with the spindle, you don't want to go up and down, because that’ll actually go against it. You could also use electrical tools that’ll help but I've just noticed over the years, the best way to get this cleaned up is just simply doing it by hand, good old-fashioned elbow grease. Make sure to get up on the column. This may take 15 to 20 minutes, but it'll look brand-new again. Replace coolant nozzles if necessary.
Touchup Paint
You may run across chipped paint and using a small amount of touchup paint makes a huge difference without making it look like the unit was dipped in paint. We get the manufacturer paint matched and use just a 2-ounce bottle. Take the touchup paint and blend in the chipped areas as much as possible.
Manufacturer Sticker
The manufacturer sticker may look tattered with grime and grit underneath. We have a local company make them for us. If you need one, we've got a bunch of them here; feel free to call the company and we'll be happy to help you out.
To get the old sticker off, you can use a putty-type knife to get under it and remove it. Once you get it off, you may see a slight outline. To put the new sticker on, you'll need the water spray bottle, your sticker, and a credit card, putty knife, or anything with a flat surface.
Spray water on the surface. Peel the back off of the sticker, line it up to the outline. You can use a leveler to make sure it's nice and straight. Starting from the center, drag the credit card or putty knife outward to get all the water out. Make sure you've got no bubbles. Spray the front, so it comes off nice and easy. Peel off front part of the sticker and wipe down the excess water with a clean cloth.