Answers to the questions
we actually get asked —
not the ones on a form.
Forty questions across seven categories, written in plain English with real numbers and honest limits. If you can't find what you're looking for, the last section has a way to ask us directly — we answer every message inside one business day.
General
Basics about who we are, what we coat, and what "powder coating" actually is.
What is powder coating, and how is it different from paint?
Powder coating is a dry finishing process where electrically charged powder particles are sprayed onto a grounded metal part and then cured in an oven at 350–400°F. During cure, the powder melts, flows, and chemically cross-links into a hard, continuous film. There's no solvent, no liquid carrier, and no drying — the powder becomes the coating through heat alone.
The practical differences from wet paint: powder is thicker (typically 2–4 mil versus 1–2 mil for paint), harder, more chip-resistant, more chemically resistant, and produces zero VOC emissions. It doesn't run, drip, or sag during application. The tradeoff is that powder is harder to touch up in the field — it needs to be done in a shop.
What parts do you coat?
Almost anything metal. Our line handles carbon steel, stainless steel, aluminum, cast iron, and forged alloys. We coat machine frames, architectural components, wheels, brake calipers, structural steel, food processing equipment, retail fixtures, motorcycle frames, roll bars, brackets, enclosures, and just about anything else that can be racked and cured. The main limits are size (24 ft × 60 in × 72 in), weight (2,000 lb per rack), and cure temperature (parts must survive 250–400°F).
Do you have a minimum order?
No hard minimum — we'll coat a single part if it needs coating. In practice, jobs under $150 in total value usually aren't economical once setup, masking, and rack space are factored in. We'll always quote honestly and tell you if a small job doesn't make financial sense for either of us.
How long has Northline been in business?
We opened in 2005 in a 4,000 sq ft bay off Chicago Drive with a single used batch oven. We moved to our current 48,000 sq ft facility on Burton Street in 2012, expanded to two coating cells in 2018, and were approved for AAMA 2605 architectural work in 2022. Still family-owned, still on Burton Street. More detail on the About page.
Are you certified or accredited?
We're ISO 9001:2015 certified and an AAMA 2605 Approved Applicator for architectural work. We're not currently certified for ITAR or DFARS work, but we regularly supply the documentation that OEMs and prime contractors require from their coating suppliers.
Can I come see the shop before committing to a job?
Yes, and we encourage it for anyone evaluating a coater for ongoing production work. Tours typically take 30–45 minutes and cover the full line from intake to shipping. Call Maria directly at (616) 452-8817 to schedule — she'll find a slot that works around the production schedule.
Process & Prep
How we actually run the line — pretreatment, masking, cure, and QC.
Why is pretreatment so important?
Because bad prep is the single biggest cause of powder coat failure — not bad powder. A premium polyester applied over a poorly prepared substrate will fail faster than an inexpensive epoxy applied over a properly pretreated one. That's why we run every part through either a media blast or a 7-stage iron phosphate line (or both) before any coating touches it.
Do you strip existing paint or powder before coating?
Yes, always. Coating over an existing finish is unreliable — old coatings fail from the substrate up, and the new powder will follow them off. We strip by blasting, chemical stripping, or burn-off depending on the substrate and the old coating. This is built into our quotes as standard, not optional.
How do you handle masking of threads and machined surfaces?
We use high-temperature silicone plugs, caps, and tape — not standard masking tape. Silicone survives the full 400°F cure cycle without leaving residue or shrinking. For production runs with many masked features, we build reusable masking fixtures that hold every plug in the same position, which speeds up the process and keeps coverage consistent across the run.
Do you use low-temperature powders for heat-sensitive parts?
Yes. Standard powder cures at 350–400°F, but we run low-temperature powders that cure at 250–300°F for parts that can't survive a standard cycle — including pre-assembled components, aluminum substrates with specific alloy considerations, and enclosures with internal electrical components. Low-temp cure requires a longer dwell time and adds a day to the standard schedule.
How do you check that the coating is the right thickness?
We measure both wet and cured film thickness. Wet thickness is checked visually against a target profile during application. Cured thickness is measured with an electronic dry-film gauge on multiple points per rack. If a part is outside the target range, we strip it and recoat — we don't ship parts that are out of spec and apologize later.
What happens if a part fails your QC check?
Failed parts get stripped back to bare metal, re-blasted, and recoated from scratch — the same six stages as the original. We don't attempt to "patch" a failed coating, because it doesn't work and just creates problems downstream. The recoated part is re-inspected before release, and we cover the cost of the redo.
Pricing & Quotes
What things cost, how we quote, and what drives the price up or down.
How do I get a quote?
Send drawings or clear photos, quantities, substrate, and any finish spec you have (color, gloss level, mil thickness). If you don't know the spec, describe the application and we'll recommend one. You can use the quote request form, email us at [email protected], or call (616) 452-8817. Most quotes go out inside one business day.
What drives the cost of a powder coating job?
Five main factors: part size and complexity (bigger parts and more masked features cost more), quantity (per-piece cost drops with volume), color and finish (stock colors are cheaper than custom matches; two-stage finishes add cost), pretreatment requirements (blasting plus chemical pretreatment is more expensive than chemical alone), and turnaround speed (rush jobs carry a premium).
Do you have a price list?
No. Every job is quoted individually because pricing depends on the specific part and the specific finish. Publishing a "standard price" for powder coating is the same as publishing a "standard price" for machine work — the range is too wide to be meaningful. We do publish typical ranges for common jobs on our automotive and services pages so you can sanity-check expectations.
Do you charge for quotes?
No. Quotes are free, and so is the intake inspection that confirms whether the quote is accurate. If we find issues with the parts during inspection that would change the quote — dents, structural problems, unexpected existing finishes — we call you before doing any work.
Is there a rush service, and how much does it cost?
Yes. Rush service gets a job through in 48 hours instead of five business days, subject to line capacity. Rush carries a 40–60% premium depending on the specific job. Call us before shipping parts if you need rush service — we can't always fit a rush job if the ovens are already booked.
Do you offer volume discounts for recurring work?
Yes. For OEMs and manufacturers with recurring production needs, we can hold a reserved production slot on a monthly, quarterly, or seasonal schedule. Reserved capacity guarantees your turnaround and lets us plan powder purchases in advance, which usually improves pricing on the recurring work. Contact us to discuss a production agreement.
Quality & Durability
How long the finish lasts, what it survives, and what it doesn't.
How long does powder coating actually last?
It depends on the environment. Indoor applications (furniture, equipment, enclosures) typically last 15–25 years. Exterior applications in the Midwest (agricultural equipment, construction hardware, automotive) last 8–15 years for standard systems and 20+ years for AAMA 2605 architectural systems. In coastal or extreme chemical environments, the lifespan depends on the specific system — we spec those jobs individually.
Does powder coating resist rust?
Yes, if it's applied correctly over properly pretreated steel. The powder itself is a barrier coating, and the pretreat layer beneath it is a conversion coating that chemically bonds to the steel and provides additional corrosion protection. A properly applied powder coat on blasted and phosphated steel will withstand 1,000+ hours of salt spray testing. On non-ferrous metals (aluminum, stainless), corrosion isn't the primary concern — adhesion and UV stability are.
Will powder coat survive brake dust and road salt?
Yes, if the system is spec'd correctly. We use TGIC polyester for wheels and chassis components because it resists brake dust chemicals and holds up to road salt in a Michigan winter. Regular cleaning helps, but the coating is designed to survive without special maintenance between washes.
Can powder coat be touched up?
Field touch-up is possible but limited. Small chips and handling marks can be covered with a matching touch-up kit that includes powder and an applicator — we supply these with every architectural shipment. For larger damage, the part typically needs to come back to the shop for a spot recoat. Deep scratches or large areas of damage usually require stripping and recoating.
What's the difference between a 1-mil and a 5-mil coating?
Film build is a tradeoff between durability and precision. Thicker coatings resist impact, abrasion, and chemical exposure better, but they also change part dimensions and can bridge into tight tolerances. Standard production work runs 2–4 mil. Heavy-build industrial and food processing coatings run 6–15 mil. Automotive work typically stays at 2–4 mil to preserve precise fits. Precision parts with tight tolerances may only get 1.5–2 mil to stay within dimensional requirements.
Turnaround & Shipping
How long jobs take, how parts get to us, and how they get back.
What's your standard turnaround?
3–5 business days from receipt to shipment for standard production work. Custom color matches add 5–15 days depending on the process (physical sample match versus custom formulation). Two-stage finishes add 2–3 days. Architectural projects are phased across 7–14 business days per production lot, scheduled against the installation sequence.
Do you ship parts, or does the customer handle that?
We ship on LTL, dedicated flatbed, or customer-arranged freight depending on the parts. Inbound and outbound handling is included in every quote. For local customers within 50 miles of Grand Rapids, we offer flat-rate delivery. For customers outside Michigan, we ship on pallets with foam padding and stretch wrap and handle all logistics.
How do I ship parts to you?
For most jobs, standard LTL freight works fine. For specialty parts — wheels, precision components, delicate finished goods — we recommend pallets with foam padding and secure banding. Contact us before shipping anything that needs special handling, and we'll give you specific packing instructions. For very small parts, UPS or FedEx ground works fine with adequate padding.
Can you hold parts after coating if my schedule changes?
Yes, for short periods. We'll hold finished parts in our staging area for up to 2 weeks at no additional charge. Extended storage beyond that is possible for a small per-pallet daily fee. For recurring production work, we can coordinate a shipping schedule that matches your assembly line's needs.
What if a shipment gets damaged in transit?
We pack parts to survive standard freight handling — foam corner protection, non-abrasive interleaving, stretch wrap, and secure banding. If something still gets damaged in transit, we file the freight claim on your behalf (as the shipping party) and coordinate a repair or recoat. Standard practice is that the customer is the consignee and the claim is between the freight carrier and us as the shipper, so you don't have to deal with the carrier directly.
Warranty & Claims
What we cover, what we don't, and how a claim actually works.
What does your standard warranty cover?
Standard production work is warranted against adhesion failure and premature coating defects for 12 months from the date of shipment. This covers things like delamination, blistering, and film defects that show up under normal use. It does not cover cosmetic damage from handling, installation, or abuse after the parts leave our shop.
Do you offer longer warranties on architectural work?
Architectural AAMA 2605 work carries the manufacturer's 20-year color-retention warranty on qualifying systems. That warranty is issued by the powder manufacturer, but we facilitate it and provide the documentation to support a claim if one is ever filed. Standard AAMA 2604 and 2603 systems carry 5-year and 1-year manufacturer warranties respectively.
What if a customer damages parts after they leave your shop?
Damage from handling, installation, or misuse isn't covered by the warranty — but we can help. We offer touch-up kits for small marks, and we can recoat individual pieces if the damage is significant. For architectural work, we keep powder from the original production batch on file so touch-ups match.
How do I file a warranty claim?
Call us at (616) 452-8817 or email [email protected] with the lot number from your certificate of conformance, photos of the issue, and a description of how the parts have been used since delivery. We'll assess it, usually within 2 business days, and if it's covered under warranty we'll schedule a recoat at no charge. If it's not covered, we'll tell you honestly and quote the repair.
What happens if I'm not happy with a job?
Tell us. We'd rather hear it from you directly than read it in a review six months later. If we got something wrong — wrong color, wrong finish, wrong masking — we fix it at our cost, no argument. If the issue is a misunderstanding about what was quoted or what was possible, we'll sit down with you and figure out a path forward. That's the entire point of a warranty.
Colors & Finishes
What we can match, what we can't, and how to get the finish you want.
What color systems can you match?
RAL Classic, RAL Design, Pantone, Federal Standard 595, most OE automotive codes, and physical samples. Standard matches pull from stocked powder at no extra charge. Custom matches add a small setup fee and 5–10 business days for powder delivery and a test panel approval.
Can you match a color from a photo?
We can quote a ballpark match from a photo, but we can't guarantee exact color from one. Screen calibration, lighting, and shadows all distort color, and two people looking at the same photo on different monitors will see different colors. Any job that requires an exact match needs a physical sample or a specific color code.
Do you charge extra for custom color matching?
It depends on the match. Standard color codes (RAL, Pantone, OE) are included at no extra charge as long as the powder is available from stock. Physical sample matching adds a small setup fee for a test panel and adds 5–7 days. Custom formulated powder — for colors that don't exist as a stock item — carries a formulation fee and minimum batch quantity. We'll always tell you the exact charge before you commit.
What gloss levels do you offer?
The full range. High gloss (85%+), satin (30–50%), matte (under 20%), and textured finishes including wrinkle and hammertone. Gloss level matters as much as color — a gloss black and a satin black look completely different on the same part. We always confirm gloss level before running the full job, and we'll send a sample at the specified gloss if there's any ambiguity.
Can you do two-tone or multi-color parts?
Yes, with limitations. Two-tone work requires masking between color applications and multiple cure cycles, which adds significant time and cost. It works best on parts with clean separation lines — think a frame where the main body is one color and a specific panel is another. Complex multi-color work usually isn't cost-effective unless the design justifies it. We'll give you a specific quote based on the geometry.
How consistent is the color across a large run?
Very consistent if we plan for it. For multi-lot production runs, we hold reserved powder from a single manufacturer batch for the length of the project so every shipment matches the approved sample. Cross-lot consistency is measured with a spectrophotometer at ΔE ≤ 2.0 (or tighter if specified). For architectural projects, we hold the approved sample on file for the full project duration.
Can you coat over anodized or chromed parts?
No, not reliably. Anodizing and chrome are hard, non-porous surfaces that powder can't bond to. We strip them chemically before blasting and coating. If your parts are currently anodized or chromed, expect a stripping charge on the quote. In some cases, if the chrome finish is already failing, we can coat over it — we'll advise during inspection.
Ask us directly.
We answer everything.
Not all questions fit into neat categories, and some things are easier to explain over the phone than in a FAQ. Send us a note, or call Maria directly at (616) 452-8817. We respond to every message inside one business day.
Send us the specs.
Get a real quote.
If your question is really about a specific job, skip the FAQ and go straight to a quote. Send us the part details and we'll come back with a firm number and turnaround date.