To get your parts ready for powder coating, finish all welding and grinding first, remove oils, tape, labels, and loose debris, deal with rust and old coatings (or let your coater blast them off), tell your coater if the parts are cast or galvanized, mark any areas that need masking, and send clear color and finish specs. Do those six things and your job moves faster, costs less to rework, and comes back looking the way you expected.
Powder coating is only as good as the surface under it, and most delays we see trace back to what a part looks like when it arrives. Here’s what we recommend, step by step.
1. Finish All Fabrication Before the Parts Ship
Powder coat is the last step, not a middle one. Welding, grinding, drilling, and cutting should all be done before parts come to us. Welding after coating burns the finish, and grinding afterward leaves bare spots.
Before you ship, look for:
- Weld spatter and sharp burrs that should be knocked down
- Rough seams and edges that need smoothing
- Holes that still need to be drilled or tapped
- Any last fit checks, so you’re not recoating a part you had to modify
If a part might need a change later, flag it. It’s easier to adjust before coating than after.
2. Get the Oil, Grease, and Residue Off
Contamination is the number one enemy of adhesion. Fingerprints, cutting fluids, lubricants, metalworking compounds, and rust preventatives all count. Powder Coated Tough, the magazine of the Powder Coating Institute, puts it simply: a dirty substrate will not accept chemical pretreatment.
You don’t need to deep clean parts yourself, since we run pretreatment in house. But you can make it easier:
- Wipe off heavy oil and coolant before packing
- Remove stickers, labels, and tape, because adhesive residue is hard to get off
- Keep parts out of dusty or greasy areas while they wait to ship
- Handle parts with clean gloves when you can
3. Deal With Rust and Old Coatings
This is a big one. Powder coating cannot go over rust. Surfaces must be clean and free of rust, grease, and other contaminants, or the finish won’t hold.
You have two options. You can remove the rust and old finish yourself, or send the parts as they are and let us handle it. Our sandblasting removes mill scale, rust, old coatings, heat treatment discoloration, and weld spatter, and it’s the prep step that comes before powder coating. We can adjust the blasting media to match your material and the finish you want. Our post on the powder coating process walks through each stage.
One more tip: blasted metal doesn’t like to wait. Powder Coated Tough notes that blasted parts shouldn’t sit around long as the freshly abraded surface is prone to oxidation. If you blast parts yourself, get them to us quickly rather than letting them sit.
4. Tell Us About the Material
Different metals behave differently in the oven. Steel, aluminum, cast parts, and galvanized steel each have their own quirks, so tell us what you’re sending, and don’t assume we can tell by looking.
Cast metal is the big flag. Powder Coated Tough explains that gases can evolve from hot dipped galvanized steel and cast metal parts, causing defects that range from pinholes to large blisters. If your parts are castings or galvanized, let us know up front so we can plan for it.
For a rundown of which metals work and which don’t, see our post on what metals can and cannot be powder coated.
5. Mark What Should Stay Uncoated
Some features shouldn’t get coated at all. Threads, bores, mating surfaces, and electrical contact points are the usual suspects. We mask these before application, using high temperature tapes and silicone plugs, because accurate masking keeps the work precise and prevents rework down the line.
To make it easy:
- Mark masked areas on a drawing, or send a photo with notes
- List thread sizes and bore locations
- Tell us if you’re supplying your own plugs or caps
- Point out any surface that must stay bare metal for grounding or fit
If you have a part that needs a specific masking approach, such as powder coating used as an electrical insulator, tell us what you need and we’ll plan for it.
6. Send Clear Color and Finish Specs
Nothing slows a job down like a vague color request. When you send parts, include:
- Color. A color code or a sample for matching. We offer custom color matching, and we can coat in customer provided colors
- Finish. Matte, gloss, metallic, or textured
- Performance needs. Outdoor use, chemical exposure, or a thickness requirement
- Inspection requirements. We can check mil thickness, color, cure with MEK testing, and adhesion with crosshatch testing
If it’s a repeat part, give us a part number or the paperwork from last time so we match it every time.
7. Plan Packaging and Logistics
Parts get nicked in transit, and you don’t want to pay to fix damage that happens before the coating even starts. Pack parts so they aren’t banging against each other, and tell us about size and weight early.
We can process items up to 10,000 pounds and 20 feet long. We also offer pickup and delivery, with logistics available for larger loads, so you don’t have to get your parts here yourself. We provide custom protective wrapping on the way out, or we can use your dunnage. Ask us if you want your finished parts returned in a particular way.
Ready to Send Parts? Call Liberty Powder Coating
We’ve been providing powder coating, sandblasting, and anodizing across Southeastern Michigan since 2012, out of our facility at 1408 Enterprise Dr. in Highland. We’re ISO 9001:2015 certified, we offer expedited processing, and free estimates are available.
Call us at (248) 222-7188, Monday through Friday, 7am to 3pm and we’ll walk you through what to send.
Frequently Asked Questions
How should I prepare parts for powder coating? Finish all welding and grinding first, remove oils, tape, and labels, deal with rust and old finishes, and tell us what material the parts are. Mark areas that need masking and send color and finish specs. We handle cleaning and pretreatment in house.
Can you powder coat over rust? No. Surfaces need to be clean and free of rust, grease, and other contaminants. We offer sandblasting and pretreatment to prepare the metal properly.
Do I need to sandblast my parts before sending them? Not necessarily. We can blast parts for you. If you blast them yourself, send them promptly so the surface doesn’t oxidize.
What areas of a part get masked? Usually threads, bores, mating surfaces, and any area that needs to stay bare. Tell us what to protect and we’ll mask it before coating.
Can you match a specific color? Yes. We offer custom color matching, and we can also coat in customer provided colors.
How big and heavy can the parts be? We can process items up to 10,000 pounds and 20 feet long.
Do you offer pickup and delivery? Yes. We offer pickup and delivery and logistics services for larger loads.
Liberty Powder Coating proudly serves Highland, Michigan and a large surrounding area throughout Michigan including Brighton, Detroit, Taylor, and Lansing. Questions about powder coating, sandblasting, or anodizing services? Contact our team today
