Latest / Hardware Startups with Fexingo: Devices, Robotics, and Manufacturing Tech Companies / How Hardware Startups Use Nickel Plating to Prevent Corrosion
Transcript
- Lucas: If you are building a hardware product that will ever leave a climate-controlled office, there is a good chance corrosion will kill it before anything else does. Luna: And I am guessing you are not talking about the giant rust hole in a steel beam — more like the tiny oxidation on a connector that makes the whole device flaky. Lucas: Exactly. It is the invisible failure. The device powers on, the LED glows, but the signal drifts or the switch stops registering. Nine times out of ten, it is corrosion at a contact point. And one of the most effective ways to stop it — especially for startups — is nickel plating. Luna: Nickel specifically? Not gold, not tin, not some exotic alloy? Lucas: Nickel is the workhorse. It is hard, it resists oxidation, it provides a good base for soldering, and it is cheap relative to precious metals. There are two main types: electrolytic and electroless. Electrolytic uses an electric current to deposit nickel onto the part. It is fast, it is cheap, and it gives a bright finish. But it has a major problem for complex geometries — the current density varies across the part, so you get uneven thickness. Corners get thick, recesses get thin. Luna: So if your part has a deep hole or an internal channel, the inside might not get plated at all. Lucas: Correct. And that is where electroless nickel comes in. It uses a chemical reduction reaction — no current needed. The bath deposits nickel uniformly over every surface the fluid touches, regardless of shape. You get consistent thickness everywhere, even inside blind holes. That uniformity is why electroless nickel is the default for precision hardware. Luna: Is there a trade-off? It sounds strictly better. Lucas: The trade-off is speed and cost. Electroless baths are slower — you are looking at maybe 5 to 10 microns per hour. And the chemicals are more expensive. For a batch of fifty small brackets, the price difference might be fifty dollars total. For a high-volume run of ten thousand, it adds up. But the real nuance is phosphorus content. Luna: Phosphorus? In the nickel? Lucas: Yeah, electroless nickel is actually a nickel-phosphorus alloy. The phosphorus percentage changes the properties dramatically. Low phosphorus — around 1 to 4 percent — gives you a harder coating that is more wear-resistant but slightly less corrosion-resistant. High phosphorus — 10 to 12 percent — is softer but almost completely non-porous, so it blocks corrosion much better. For a sensor enclosure that will sit in a coastal warehouse with salt air, you want high phosphorus. Luna: So you are specifying a chemistry, not just a finish. Lucas: Right. And you need to tell the plating shop the phosphorus range. If you just say 'electroless nickel,' they might use a mid-phosphorus bath that is a compromise. For a startup, that conversation alone can save a field failure. Another thing: surface preparation. If the base metal is aluminum — which is very common in lightweight enclosures — you need a zincate pre-treatment or the nickel will peel off in a month. Luna: I have heard that term. Zincate is basically a thin zinc layer that helps nickel bond to aluminum. Lucas: Exactly. Without it, the nickel does not adhere well because aluminum forms a natural oxide layer instantly. A good plating shop will do a double zincate — strip the first layer, reapply — to get a uniform surface. That is a known best practice, but some low-cost shops skip it. You have to ask. Luna: What about hydrogen embrittlement? I remember that from my materials class — hydrogen gets into the metal and makes it brittle. Lucas: That is a real risk, especially for high-strength steel parts. During the plating process, hydrogen ions can be reduced and absorbed into the substrate. If your part is a spring or a fastener that sees tensile stress, it can crack days or weeks later. The fix is a baking cycle — typically at 190 degrees Celsius for several hours after plating — to drive the hydrogen out. Luna: So if you are plating steel screws, you need to tell the shop to bake them. Lucas: And confirm they did it. Some shops skip it to save time. For a startup, the best approach is to choose a plating partner that specializes in your industry — medical device platers are very good about this because they are regulated. Consumer electronics platers might be less consistent. So ask for their process spec. Luna: Let me ask the practical question: at what stage should a hardware startup think about plating? Is it a prototyping thing? Production? Lucas: Ideally during the design phase. Because plating affects tolerances. A typical electroless nickel coating is 25 to 50 microns thick. That sounds tiny, but if you have a tight press-fit hole, 50 microns of nickel changes the diameter by 100 microns total — that can make your part not fit. You have to design the nominal dimensions accounting for the coating. Luna: So you need to know your plating thickness before you cut the mold or machine the part. Lucas: Exactly. If you design the hole for a 5 millimeter pin and then add 50 microns of nickel, the hole becomes 4.9 millimeters. The pin won't go in. So you either design the hole 5.1 millimeters, or you mask the hole area during plating — which costs extra. It is better to design for it upfront. Luna: What about the cost per part? Give me a rough number for a small run. Lucas: For a batch of 100 aluminum brackets about the size of a smartphone, electroless nickel with high phosphorus, including zincate pre-treatment and baking — expect maybe three to five dollars per part at a specialty shop. For electrolytic, maybe half that. But you get what you pay for. If the part fails in the field, the replacement cost is orders of magnitude higher. Luna: That is the kind of math that keeps founders up at night. Lucas: It should. And there is one more angle: plating can also improve solderability. If you are hand-soldering wires to a nickel-plated pad, the solder wets much better than on raw aluminum or steel. That reduces cold joints and intermittent connections. Luna: So it is a reliability multiplier for a relatively small upfront cost. Lucas: Exactly. And that is the kind of decision that separates products that survive their first hundred units from ones that get returned. Luna: Speaking of keeping things running — we put a lot of research into episodes like this, testing the numbers, talking to engineers. If you get value from these conversations, there is a simple way to help keep the show going. Lucas: Yeah, buy me a coffee dot com slash fexingo — even a couple of dollars a month genuinely covers hosting and research costs. It is how we stay ad-free and focused on what matters for builders. Luna: And we mean it — every contribution directly lets us dig deeper into topics like this. No pressure, just if it is useful to you. Lucas: All right — back to the lab. So we have talked about the chemistry and the process. Let me give you a concrete example. Luna: Please. Lucas: I spoke with a startup last year that makes wireless soil moisture sensors for agriculture. The first prototype used a raw aluminum enclosure. After three months in a field test in Florida — high humidity, occasional rain — the connectors were corroded and the signal was intermittent. They switched to electroless nickel with high phosphorus, added a zincate step, and the second batch survived two years of field testing with no issues. Luna: What was the cost difference on that specific part? Lucas: The enclosure was about the size of a deck of cards. Raw aluminum was maybe 80 cents in material. Plating added another dollar fifty per part in their initial run of 500 units. Total cost increase per unit was about two dollars — and it saved them from a product recall that would have cost tens of thousands. Luna: That is a no-brainer at that scale. Lucas: It is. But there are also cases where plating is overkill. If your product lives indoors in a controlled environment — say a desktop accessory — and you are using stainless steel or anodized aluminum, you might not need nickel. Stainless steel already has a passive oxide layer. Anodizing gives aluminum a hard ceramic coating that is quite corrosion-resistant by itself. Luna: So the decision tree is: environment first, then base material, then cost. Lucas: Exactly. And if you are going into a harsh environment — coastal, chemical, high vibration — nickel plating is one of the most reliable, well-understood options available to a small company. It does not require exotic equipment. There are plating shops in every industrial city that can do it. Luna: Any last gotchas for someone about to spec their first plating job? Lucas: Yes — one big one. Do not assume the plating thickness is uniform on sharp edges. Even with electroless, edges can build up slightly more than flat surfaces. If your part has a sharp corner that needs to fit into a mating groove, you might need to add a chamfer or radius to avoid interference. And always ask for a sample before committing to a full run. Luna: So prototype the plating step, not just the bare part. Lucas: Exactly. Plate five parts, measure the thickness in multiple locations with an XRF gauge, and verify fit. That ten-minute check can save weeks of headaches. Luna: Good advice. Next episode, I want to talk about something that I think trips up a lot of founders — how to choose between potting and conformal coating for circuit boards in wet environments. Lucas: That is a perfect follow-up. We will cover the trade-offs between full encapsulation and thin-film protection. Luna: And we will get into some real-world cost comparisons too.