A conformal coating that’s thin enough to spray evenly over a populated PCB and one that’s thick enough to bridge a seam without running are solving opposite application problems, even though both end up protecting the same kind of electronic assembly. Incure’s Pyra-Sil™ silicone conformal coating line spans that range across five grades, split primarily by viscosity and hardness, with one grade breaking from the rest on cure method entirely.
Four Room-Temperature Grades Span a Wide Viscosity and Hardness Range
Pyra-Sil™ 864, 872, 872F, and 880 are all one-part, room-temperature-cure conformal coatings for sealing, potting, seam-filling, and encapsulation on metals and plastics, but they sit at different points on the viscosity and hardness spectrum. 864 is thin at 400–600 cP and the hardest of the four at Shore A20–A30, with the fastest surface cure in the line — 5 minutes at room temperature, or 25 seconds accelerated at 150°C. 880 is similarly thin at 800–1,200 cP but the softest grade in the entire line at Shore A8–A13, tacking free in 15 minutes. 872 and 872F share the same Shore A12–A18 hardness and sit at the thick end of the spectrum — 872F at 5,000–9,000 cP, 872 thicker still at 8,000–12,000 cP — and the two are effectively the same base formulation with one added capability: 872F fluoresces under blacklight for coverage inspection and cures tack-free faster, in 10 minutes against 872’s 15, while otherwise sharing the same mechanical profile. That fluorescing-versus-standard pairing is worth checking for by name rather than assumed, since not every grade in the line carries an “F” variant — 864 and 880 don’t offer a fluorescing counterpart, so a line that wants blacklight-verifiable coverage at those two grades’ specific viscosity or hardness points doesn’t have a direct drop-in option within this family.
890 Trades Room-Temperature Convenience for a Fast Oven Cure
Pyra-Sil™ 890 breaks from the other four on cure mechanism entirely: a one-part, 100%-solids coating that cures exclusively by heat, fully curing in just 20 minutes at 130°C rather than offering a room-temperature path at all. It’s also the thinnest grade in the line by a wide margin at 100–125 cP, and it fluoresces under blacklight the same way 872F does. That combination — very low viscosity plus a fast, complete oven cure — makes 890 the grade to reach for on a production line that already has oven capacity and wants a short, predictable cure cycle rather than a 24-hour room-temperature wait, at the cost of needing that oven step in the first place. Where 864 only offers an accelerated cure as an option alongside its room-temperature path, 890 has no room-temperature path at all — a distinction worth confirming before specifying it on a line that can’t reliably hold parts at 130°C, since there’s no fallback cure schedule to fall back on if oven capacity is temporarily unavailable.
Email Us with your coverage requirement, whether the line has oven capacity, and whether coverage needs blacklight verification, and Incure’s engineers can confirm which Pyra-Sil™ conformal coating grade actually fits.
Matching Viscosity to Application Method
The thin grades — 864, 880, and 890 — are suited to spray, dip, or automated dispensing over populated boards and fine-feature components, where a thick coating would pool unevenly or bridge closely spaced leads. The thick grades — 872 and 872F — are better suited to seam-filling and gap-bridging work where the coating needs to hold its shape on a vertical or contoured joint rather than self-level away from where it was placed. All five share the same broad -45°C to 260°C service range and roughly 220–225 PSI tensile strength, so viscosity and cure method — not mechanical performance — are the variables actually driving grade selection across this line. That consistency also means a line switching between grades for process reasons, such as moving from a thin sprayable coating to a thicker gap-filling one on a redesigned enclosure, isn’t trading away temperature tolerance or bond strength in the process.
Where the Line Fits
High-volume PCB assembly lines running spray or automated dispensing equipment favor the thin grades — 864 for the fastest room-temperature surface cure, 880 for the softest, most flexible finish, and 890 wherever an existing oven step makes a 20-minute heat cure more attractive than a 24-hour room-temperature wait. Seam-filling and gap-bridging work on housings and enclosures relies on 872 or 872F’s thicker, gap-holding consistency, with 872F chosen specifically when coverage needs to be blacklight-verified before the assembly moves downstream. Facilities running Incure’s Ultra-Illumina™ UV conformal coating line for fast UV-cure PCB protection can add this Pyra-Sil™ silicone line specifically where the assembly’s geometry, shadowed areas, or existing process equipment favor a room-temperature or oven cure over UV exposure. Facilities already running Incure’s RTV silicone adhesive line for structural potting and bonding can add these conformal coatings for surface-level protective coverage on the same assemblies.
Contact Our Team to confirm the Pyra-Sil™ conformal coating grade for your coverage and cure requirement.
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