FI-55 is a white powder used to build the working bath for direct electroless copper plating on aluminum and aluminum alloy surfaces. Aluminum is awkward to plate: an oxide film forms almost immediately, and a conventional electrolytic copper strike usually needs a zincate sequence before copper will hold. Here the work is cleaned, rinsed and immersed, and the copper is deposited chemically out of the plating solutions rather than driven on by current.
The result is a copper layer that follows the shape of the part — a continuous copper skin around the strand on wire, an even copper face across flat areas and into recesses on sheet and extrusions. Copper on aluminum is wanted for three reasons: it makes the surface solderable and lowers contact resistance, it gives a decorative copper tone, and it provides a keying layer that nickel, tin, silver or a coating will bond to.
The sequence is short: clean with the FI-050 aluminum wire non-corrosive cleaning agent, rinse with water, then immerse in the copper bath. One make-up covers wire runs, racked parts and dipped bundles, so a shop handling both wire and shaped components keeps a single product on the shelf. Typical buyers are wire and cable makers, decorative aluminum fabricators, anodizing plants adding a copper finish, and industrial buyers who need a copper strike on aluminum before further plating.
| Form | White powder |
| Specific gravity | Approximately 1.05–1.15 |
| Substrates | Aluminum and aluminum alloy wire, sheet, extrusions and castings |
| Deposit appearance | Uniform purple-red copper layer |
| Pre-clean | FI-050 aluminum wire non-corrosive cleaning agent |
| Rinse | Water rinse between cleaning and plating |
| Application method | Immersion in the made-up copper bath |
| Typical uses | Conductive copper on aluminum wire, decorative aluminum, aluminum alloy building materials |
Conductivity where the current crosses
The copper skin carries current at the contact and the joint while the aluminum core carries it along the length. That split is why copper on aluminum wire is worth the extra step: you keep aluminum's weight and cost and put a low-resistance, solderable metal exactly where the connection happens.
Even coverage on awkward geometry
Because electroless plating of copper does not depend on current reaching the surface, recesses, wire bundles, threaded areas and the inside of a tube come up with the same copper as an exposed face. Parts that would need re-racking in an electrolytic bath can go through in a single immersion.
Fewer steps on the floor
Cleaning, rinsing and plating replace the longer strike sequence normally needed to get copper onto aluminum. Fewer tanks means less drag-out, less handling damage between stages and fewer places for the job to go wrong.
Powder that is easy to weigh and easy to freight
The product ships as a powder, so it is charged by weight into the tank rather than pumped out of a drum, and a box of powder is far lighter to move and store than the equivalent volume of liquid concentrate.
A base the next layer will hold
The copper layer takes nickel, tin, silver, solder and organic coatings, so a copper-plated aluminum part can carry on down the line rather than stopping at the copper stage.
Simple bath control
The working bath for the electroless plating process is built from copper sulfate, the powder and water, with no multi-additive routine to keep in balance, and the operator reads the result off the colour of the part. For industrial metal plating lines running several processes, that is one less bath to hold in tight specification.
| Payment terms | 100% T/T in advance |
| Minimum order quantity | Varies by chemical; confirmed with our sales team per order |
| Lead time | 2 weeks |
| Packing | 10 kg/box; 25 kg or 50 kg/bag; 20 kg/25 kg/30 kg/200 kg/drum; 1000 kg/IBC drum |
| Shipping | Per the terms agreed in the current contract |
| Warranty | Inspection certificate issued after delivery stating the batch number and warranty period |
| Wholesale and bulk supply | Quoted against quantity and packing through your sales contact |
What the bath is built from
The working solution is copper sulfate at 10–20 g/L plus the FI-55 powder in water, and both are held by analysis rather than by counting additions. The powder charge is set by tank volume, so send the tank size with your first order and we will confirm the weight for the make-up.
Temperature and immersion time are set per line
Neither figure is fixed in the product data, because the right pair depends on your aluminum grade, the wire diameter or part shape, the line speed and the copper thickness you are aiming for. Send those four details and we will confirm a starting temperature and dwell time; a short run on scrap of the same alloy then shows whether the line needs longer or warmer. A continuous wire run and a racked part with deep recesses rarely want the same immersion time from the same bath.
No current density, no rectifier
Copper comes down chemically in this electroless plating process, so there is no anode, no rectifier and no current density to balance across a rack. What replaces amperes as a control is solution movement and time: keep the work moving, or the bath circulating, so fresh plating solutions reach the surface, and set the coating through dwell.
Read the part to judge the window
Inside the window the work comes out with a uniform purple-red copper over the whole surface, including recesses and the gaps between strands. Streaky, patchy or slow coverage usually traces back to the FI-050 clean or to the rinse, and then to a copper sulfate level that has fallen below the working range — check those two before you change temperature or time.
Holding it through a shift
Copper is consumed on the work and dragged out on the parts, so the bath gets leaner as the shift runs. Titrate the copper sulfate, bring it back into the 10–20 g/L range, replace the powder lost to drag-out and keep the level steady. The made-up solution is quoted at a specific gravity of approximately 1.05–1.15, which gives a quick check between analyses; confirm the analysis interval for your throughput with your sales contact.
Settle the tank before the first charge
Check the tank material, the rack coating and the water you will use for make-up and rinsing with us first. A metal plating line that already runs nickel or tin usually has a spare tank that suits this bath; a line that previously ran an electrolytic copper strike should give it a tank of its own.
Thickness follows dwell, not a number on the drum
The product data does not set a micron figure, because how thick the electroless plating of copper comes out depends on how long the work stays in the bath, the bath temperature, the copper sulfate level inside the 10–20 g/L range and how readily fresh solution reaches the surface. Give us the target thickness together with the substrate and line details, and we will confirm a starting immersion window.
Measure a first-off part
Agree with your quality team whether thickness is read from a cross-section or by XRF, and how many parts per shift are checked. A measured first-off part from each run is worth more than a nominal figure, because the same bath gives a different result on a 1 mm wire and on a thick extrusion.
Write the appearance criterion down
A pass is a uniform purple-red copper across the whole surface — full coverage into recesses, no bare aluminum showing through, no loose dark smudge that wipes off. Put that wording on the acceptance sheet so the operator and the inspector are judging the same thing.
Fix the adhesion test before the first run
Bend, tape or pull testing to your own standard is the usual way to accept adhesion on this layer. If a part fails, look at the FI-050 clean and the rinse first: aluminum that dries between cleaning and plating, or carries polishing wax into the bath, will plate but will not hold.
Test corrosion on the finished stack
The copper layer is a conductive, keying layer; where corrosion resistance is the requirement, the coupon carries the full stack — copper plus nickel, tin or a sealing coat — and is tested to the neutral salt spray hours your customer specifies. Agree the method and the hours beforehand so both sides read the same result.
Trial before the first production batch
Ask your sales contact for a sample, run it on your own wire or parts, and sign off thickness, colour, adhesion and corrosion against your own standard before the bulk order goes in. Everything learned in that trial carries straight over to the production bath.
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Fengfan is a leading provider of metal plating solutions, specializing in electroless copper plating for aluminum wire. Our commitment to precision is reflected in our technologies and industry expertise. We serve a diverse range of industries and offer services such as aluminum anodizing, electroless nickel plating, and zinc nickel plating. Our products are designed to improve durability, conductivity, and corrosion resistance in demanding applications. We prioritize quality and customer satisfaction, and our skilled professionals provide tailored solutions for each client. With a focus on continuous improvement and sustainability, Fengfan continues to set the standard in metal plating.
Our electroless nickel plating services are designed for durability and corrosion resistance in industries that demand longevity and reliability. Using advanced techniques, we apply a uniform coating to each component to support a longer service life and consistent performance. This service is suited to businesses looking to reduce maintenance costs and improve the return on their equipment investment. Our metal plating expertise is focused on delivering results that stand up to demanding service conditions. Please confirm the substrate, coating thickness, and performance requirements for your parts.
Our aluminum anodizing service is designed to provide surface protection and aesthetic appeal. Through precise control of the anodizing process, we achieve consistent, high-quality finishes that improve the appearance and durability of anodized aluminum products. This service is ideal for manufacturers seeking to improve both the visual and functional aspects of their products and to meet demanding industry standards. Please confirm the alloy, finish, and performance requirements for your application.
Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.
Aluminum and aluminum alloy work — wire, sheet, extrusions and cast or machined parts. Wire is the most common job, but the same bath also runs on decorative and architectural parts where a copper finish is wanted instead of anodized aluminum. Steel, copper and zinc substrates need a different process.
No. The copper comes down chemically from the plating solutions, so there is no anode, no rectifier and no current density to balance across the rack. That is what lets the coating reach recesses and the inside of a bundle at the same rate as an exposed face.
A powder. The working bath is made up on site with copper sulfate and water, and the powder is charged in by weight. Confirm the powder charge for your tank volume with your sales contact the first time you build the bath, then keep those figures for repeat make-ups.
How thick the electroless plating of copper comes out is set by immersion time and bath condition rather than by a fixed setting on the product. Tell us the copper thickness your part needs and we will confirm the immersion window to start from. Adhesion and corrosion acceptance should be agreed against your own test standard before the first production run, because the target differs from part to part.
Maintenance follows throughput, drag-out and the water you use, so the interval is set on your line rather than on a fixed schedule. When you set the line up, confirm the top-up and analysis routine with your sales contact so the bath does not drift between checks.
Talk to your sales contact about what your line needs. Packing format, batch documentation and order quantity are matched to the order, and where a change to the product itself is required it is reviewed against your process before anything is quoted.
Fengfan has supplied the surface finishing industry since 1984, and the range covers the plating, anodizing and coating stages of a line used for industrial metal plating. We supply electroplating additives and chemical intermediates, and the technical answers come from people who work with these baths day to day.
Because the copper bath is one stage of a longer line. We can cover the cleaning before it and the nickel or the protective coating after it on the same order, so you are not reconciling three suppliers' documents against one process. Questions come back answered against your bath and your substrate, not read off a catalogue.
Process support before and after the sale: help matching the bath to your substrate and line, the SDS and composition information your EHS team needs, batch documentation with the goods, and answers on how the bath behaves once it is running.
