Finishing
Metal Finishing and Powder Coating
Most fabrication quotes stop at the bare part. Ours does not. We manage finishing as part of the job, so the parts that arrive at your dock are the parts you actually intended to install: coated, masked, hardware installed, inspected, and packed.
Finishing is performed by qualified finishing sources we have worked with for years, all within a short drive of our plant in Miami Gardens. They run under our purchase order, to your print callout, and the parts come back to us for inspection before they ship to you. You issue one PO, hold one lead time, and call one person when something needs attention.
One Purchase Order
No separate finishing vendor to source, qualify, schedule, or chase.
One Lead Time
Finishing is built into the quoted date, not added to it after the fact.
One Point of Accountability
If a finish is wrong, it is our problem to fix. You do not arbitrate between two suppliers.
Inspected Before It Ships
Finished parts return to our floor for inspection and hardware installation, not straight to you.
Capability
Finishes We Supply
Specify the finish on your print the way you normally would. If a callout is ambiguous or a spec has been superseded, we will flag it during quoting rather than guess.
Powder Coating
The workhorse finish for enclosures, racks, chassis, and frames. Durable, available in effectively any RAL or custom color, and cost effective at volume. Texture and gloss level to your specification.
Wet Paint
For parts where powder is not appropriate, including heat sensitive assemblies, very large weldments, and specific military and industrial coating specs.
Anodizing
Type II and Type III hard anodize on aluminum, clear or dyed. Standard for heat sinks, machined details, and parts needing wear resistance without added thickness.
Chemical Conversion Coating
Chem film and alodine per MIL-DTL-5541. Common where a part needs corrosion protection while remaining electrically conductive for grounding and bonding.
Passivation
For stainless steel, removing free iron from the surface to restore corrosion resistance after fabrication and welding.
Plating
Zinc, nickel, and other electroplated finishes per the applicable ASTM specification, typically on hardware and steel details.
Silkscreen and Overlays
Panel legends, logos, and graphic overlays applied and registered to the finished part.
Grain and Mechanical Finishes
Directional grain, bead blast, and deburred edge treatments on stainless and aluminum where appearance is the requirement.
Design Notes
What to Get Right Before Finishing
Finishing problems are almost always design or sequencing problems that showed up late. A few things worth settling while the print is still open.
Masking
Every surface that must stay bare needs to be called out: ground pads, bearing surfaces, mating faces, threaded holes, and connector cutouts. Masking is manual labor and it is priced by how much of it there is. Consolidating masked areas costs less than scattering them.
Hardware Sequencing
Pressed hardware installed before coating gets coated. Hardware installed after coating leaves bare threads. Which one you want depends on whether you need thread conductivity or corrosion protection, so tell us rather than leaving it to interpretation.
Grounding and Bonding
Powder coat is an insulator. If an enclosure needs continuity between panels, the bonding path has to be designed in with masked pads, thread forming hardware, or paint piercing washers.
Edge Coverage
Powder pulls away from sharp edges as it flows. A small break or radius on exposed edges holds film thickness where corrosion otherwise starts.
Color and Gloss
A RAL number alone does not fully define a finish. Gloss level and texture change the appearance substantially. If color match matters, ask for a sample before the production run.
Tolerance Stack
Coating adds thickness, typically two to four thousandths for powder. On close fitting parts and press fit features, that has to be accounted for in the design, not discovered at assembly.
South Florida
Corrosion Is Not Theoretical Here
Salt air, humidity, and heat make coastal Florida one of the harder service environments in the country. Equipment that holds up fine in a conditioned plant in the Midwest will chalk, blister, and rust here, and it usually fails at the same places: sharp edges, weld seams, dissimilar metal joints, and fastener heads.
We have been fabricating for coastal service since 1979, including a long run of marine work and outdoor rated enclosures for energy and telecom. If your equipment is going outdoors in this climate, tell us. Material selection, joint design, and finish specification all shift, and it is far cheaper to shift them now than to replace enclosures in the field in three years.
Finishing pairs with the rest of what we do. See enclosures, fiber laser welding, and our material guide.
Common Questions
Frequently Asked Questions
Do you do finishing in house or send it out?
Both, and we are direct about which is which. Deburring, graining, sand blasting, hardware insertion and laser part marking happen here. Powder coating, anodizing, plating and silkscreen go to qualified finishing partners we have used for years. Either way the parts stay on our job, on our schedule, and come back here for final inspection before they ship to you.
How much does finishing add to lead time?
Plan on three to five business days for powder coat or anodize on top of fabrication. Plating and multi-step finishes run longer. If a date is tight, tell us up front and we will schedule the finishing slot when we release the job instead of after the parts are made.
Why does finishing cost more per part on small quantities?
Finishing is charged by the run, not by the piece. The line has to be set up, parts racked, and color changed over whether you are running 10 parts or 1,000. That fixed cost divides across whatever is in the batch. It is the same reason a 25-piece order carries more setup per part than a 500-piece order.
Can you mask threads, holes and ground points?
Yes. Masking is manual labor, so it is priced per part and it is worth calling out on the drawing rather than assuming. Threaded inserts, press-in hardware, bearing bores and any surface that needs a conductive path to ground should be identified on the print so the coating does not break electrical continuity or bind a thread.
Powder coat, anodize or plating: which should I specify?
Powder coat gives you the widest color range and the thickest, most durable film, and it works on steel and aluminum. Anodizing is aluminum only, adds almost no thickness, and keeps tight tolerances intact. Plating is what you specify for corrosion protection on steel hardware and for conductivity. We have a full comparison written up, and if you tell us the environment the part lives in we will tell you which one we would put on it.
Do you match custom colors?
Yes. Give us the RAL number, the Pantone reference or a physical sample. Standard RAL colors are stocked and run fast. A custom match is a special batch of powder, which means a minimum order of material and a longer lead time, so it is worth confirming before you commit a program to it.
Can you finish parts you did not fabricate?
Yes, though most of our finishing work moves through as part of a complete job. If you have parts cut elsewhere that need finishing, send drawings and quantities and we will quote it, but the economics usually favor letting us do the whole part since you are otherwise paying freight twice.
Next Step
Send Us a Print
Email your drawing package to sales@mjmmfg.com or call (305) 620-2020. Send STEP or DXF files with a dimensioned PDF and we will come back with pricing, lead time, and any manufacturability notes worth flagging before you release the design.
MJM Manufacturing, Inc. — 5205 NW 161 Street, Miami Gardens, FL 33014. CAGE Code 0YLX1.