Silicone

Protective Peelable Coating: Incure Pyra-Sil™ 899

Finished parts pick up most of their damage between operations: in the wash, on the rack, in transit, and on the bench during the next assembly step. A temporary coating that goes on fast and peels off clean stops that damage without adding a permanent film. Incure Pyra-Sil™ 899 is built for that job. What Pyra-Sil™ 899 is Pyra-Sil™ 899 is a one-part, self-leveling protective coating that forms a tough, flexible skin over a surface and then peels away cleanly when the part is ready for use. It cures by reaction with atmospheric moisture, reaching a tack-free surface in about 15 minutes at normal room conditions, and it can be applied by brush, spray, dip, or automated equipment. Once cured, the film resists weathering, moisture, UV exposure, and elevated temperature, so parts stay protected through storage and shipping. Because it is a silicone-based film, it removes without leaving residue on metals, most plastics, painted surfaces, and finished wood. Key properties and what they mean Clean peel. The film releases in one piece and leaves the underlying finish untouched, so there is no solvent wipe-down or scrubbing step before the part goes into service. Fast tack-free time. A roughly 15-minute skin means parts can be handled and stacked quickly instead of tying up rack space while a slow coating sets. Self-leveling. The coating flows to an even thickness, so coverage is consistent without careful technique. Environmental resistance. The cured skin shields against moisture, salt, UV, and handling abrasion during outdoor storage and long transits. Where Pyra-Sil™ 899 fits Metal fabrication and finishing: protecting polished, plated, anodized, and painted surfaces from scratches and fingerprints between operations. Automotive and aerospace: shielding machined and finished components during subassembly and transport. Electronics manufacturing: covering connector faces, sealing surfaces, and optical windows during handling. Industrial equipment: protecting precision surfaces on tooling, dies, and instrument housings in storage. Renewable energy hardware: guarding finished enclosure panels and reflective surfaces during outdoor staging and installation. Application practice Start with a clean, dry surface. Oil, dust, or moisture under the film reduces adhesion and can cause it to lift early or tear during removal. Apply an even coat at the thickness recommended on the datasheet; too thin and the film tears when you try to peel it, too thick and it wastes material and cures more slowly. Let the coating reach a full cure, not just tack-free, before exposing parts to handling or weather. For removal, lift an edge and pull the film back on itself at a shallow angle. On complex geometry, a slightly heavier film peels more reliably than a thin one. If you are protecting an optically critical or sealing surface and need to confirm the film leaves no trace, Email Us with the substrate and finish. Failure modes and prevention Film tears during removal: the coat is too thin or was applied over a contaminated surface. Increase film thickness and improve cleaning. Film lifts early in storage: moisture or oil under the coating, or an incomplete…

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August 14, 2024
Conformal Coatings / Cyanoacrylate / Epoxy / Glass Adhesives / Optical Adhesives / Plastics Adhesives / Silicone / Threadlockers / UV Adhesives

Adhesive Failure: Root Causes and Effective Solutions

When a bonded joint lets go, the adhesive is usually blamed and rarely at fault. Most adhesive failures trace to how the surface was prepared, how the joint was loaded, or how the environment attacked the bond line. Reading the failure surface tells you which one, and that points straight to the fix. Two failure modes, two different problems Adhesive failure: the break runs cleanly along the interface, leaving one substrate bare and the adhesive stuck to the other. This means the adhesive never properly wet or bonded to that surface, almost always a preparation or compatibility problem. Cohesive failure: the break runs through the adhesive itself, leaving material on both substrates. This means the interface was sound and the adhesive was simply overloaded, under-cured, or degraded. Pulling a failed joint apart and looking at the surfaces is the fastest diagnostic you have. The common root causes Poor surface preparation: oil, mold release, oxide, dust, or moisture forms a weak boundary layer the adhesive bonds to instead of the substrate. This is the single most frequent cause of adhesive failure. Wrong adhesive for the substrate: low-energy plastics, oily metals, and plated surfaces need specific chemistries or primers. A general-purpose adhesive on polypropylene will peel off. Bad joint design: loading a bond in peel or cleavage instead of shear can cut the effective strength by ten times. Cure problems: off-ratio mixing, inadequate mixing, low temperature, or an incomplete UV dose all leave the adhesive below full strength. Environmental attack: heat above the glass-transition temperature, water ingress, solvent contact, and repeated thermal cycling all degrade a bond over time. Differential expansion between dissimilar materials is a major driver, explained in how CTE mismatch causes adhesive bond failure. Overload: the joint simply saw more force, vibration, or movement than it was designed for. The solutions Standardize surface prep: a written clean, abrade, clean sequence with a maximum time from prep to bond, applied the same way by every operator Match the adhesive to both substrates and the environment: check compatibility data and use primers or surface treatment on difficult materials. Grade guidance for plastics is in matching a plastic bonder grade to substrate and mechanical demand, and for glass and metal in matching a UV glass and metal bonder grade to viscosity and tensile requirement Design for shear: maximize overlap area, keep the bond line thin, add edge fillets, and use toughened grades or fasteners where peel is unavoidable Control the cure: metered dispensing for two-part systems, verified light dose for UV, clamping pressure during cure, and a heat post-cure where allowed Qualify against the real environment: soak test coupons at service temperature and humidity, then pull them, before committing to production Email Us with a description of the failure and we will help identify the cause. When adhesive is not enough Some joints carry loads or see conditions that no adhesive alone should be asked to handle. For high-stress structural connections, combine the adhesive with mechanical fasteners so the fasteners carry peak…

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July 22, 2024
Silicone

Peelable Silicone Masks: Applications and Benefits

Soldering, coating, and blasting all need clean boundaries, and the mask that defines them has to survive the process and then leave without a trace. Peelable silicone masks do both: a conformable liquid that cures into a heat-resistant film and peels away clean by hand. What a Peelable Silicone Mask Is A peelable silicone mask is a liquid silicone applied to a surface or keep-out area, cured into a tough elastic film, and removed intact after the protected process is complete. Silicone chemistry gives it two advantages over acrylic and latex peelable masks: High temperature resistance. Silicone films tolerate solder and coating-bake temperatures that soften or char organic peelable masks. Deep conformability. Silicone's flexibility lets the film follow steps, holes, and fine features closely, sealing edges that a rigid film would bridge. Other defining properties: Clean, residue-free removal, with enough cohesive strength to peel in one piece. Chemical resistance to many solvents, fluxes, and plating chemistries, varying by grade. Selective application, dispensed only where a boundary is needed. Benefits Over Tape and Boots Higher throughput. Dispense-and-cure is faster than cutting and positioning tape or fitting reusable boots, and removal is a single peel. Sharp, repeatable edges. A dispensed boundary gives a consistent line for solder, coating, or blast media. No adhesive residue. Nothing to clean off the protected surface afterward. Coverage of complex geometry. The liquid seals around pins, vias, and raised features that tape cannot follow. Reduced damage risk. Gentle peel release does not lift coatings or stress delicate surfaces. Applications PCB soldering: protecting connectors, gold fingers, press-fit areas, and sensitive components during wave and selective soldering, and preventing solder bridging in keep-out zones. Conformal coating: masking connectors, test points, and grounding pads before coating so they stay clean and contact-ready. Surface finishing: shielding non-process areas during painting, powder coating, and electroplating for clean, defined finishes. Blasting and peening: protecting threads, bearing surfaces, and finished faces during abrasive blast and shot peen. Component protection during assembly: temporary cover for connectors and optical surfaces against scratches and dust in handling. Choosing the Right Mask Process temperature. The primary selection factor for solder masking. Choose a grade rated above the peak the mask will see, including reflow and wave spikes. A mask that softens during soldering fails and contaminates the joint. Chemical exposure. Plating baths, strippers, fluxes, and cleaning solvents each attack different films. Confirm resistance to the specific chemistry rather than a general rating. Peel behavior. The mask must hold through the process and release without effort afterward. Match peel strength to the substrate and the process duration; too aggressive defeats the purpose, too weak lets the film lift mid-process. Viscosity and film build. Non-slump and gel grades build thickness in one pass and hold vertical edges; lower-viscosity grades self-level for thin, uniform coverage. Choose from the required thickness and part orientation. Cure method and access. UV and dual-cure grades fix in seconds under a lamp and finish shadowed areas by moisture cure. Room-temperature moisture-cure grades need no equipment but…

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June 8, 2024
Silicone

UV Curable Silicone: Fast-Curing, Light-Activated Solutions

Traditional silicone cures over hours as moisture works in from the surface, which limits throughput and leaves thick sections soft for a long time. UV curable silicone fixes in seconds under a lamp, combining silicone's flexibility and temperature range with a production-friendly cure. What UV Curable Silicone Is UV curable silicone is a one-part silicone that polymerizes rapidly when exposed to UV light. Many grades are dual cure: the UV mechanism fixes the exposed material in seconds, and a secondary moisture-cure mechanism finishes any shadowed silicone over the following hours. This gives fast handling strength without leaving deep or hidden sections uncured. It keeps the core silicone properties: Wide service temperature, commonly from about -55 C to 200 C or higher. High flexibility and elongation, so seals and coatings move with the substrate. Vibration and shock damping from the low-modulus cured rubber. Moisture, ozone, and UV resistance for outdoor and harsh-environment service. Good dielectric strength for electrical sealing and coating. Advantages Over Standard Silicone Seconds to handling strength. Assemblies move down the line immediately instead of curing on a rack. On-demand cure. The silicone stays workable until the light fires, so beads can be inspected and parts positioned first. Consistent through-cure. The UV mechanism sets the bulk immediately rather than waiting for moisture to diffuse through a thick section. Lower work-in-process. No large curing area or long dwell between stations. Solvent-free. One-part, 100 percent solids chemistry with minimal shrinkage. Applications Form-in-place gaskets (FIPG): a silicone bead dispensed onto a housing flange and cured in place, replacing die-cut gaskets with an exact-fit seal. Sealing and potting: environmental seals around connectors, enclosures, and lighting assemblies, and low-stress potting of components that need a compliant surround. Conformal coating: a flexible protective film on boards that run hot or vibrate. Bonding: joining glass, metal, and many plastics where a flexible, temperature-tolerant bond line is needed. Strain relief: compliant fillets where wires and connectors meet a board or housing. Choosing the Right Grade Cure format. Confirm whether the grade is UV-only or UV plus moisture. UV-only grades need full light access to every part of the deposit; dual-cure grades tolerate shadowed geometry. Match this to the joint or bead design. Viscosity and flow. Self-leveling grades suit thin coatings and filling; non-slump grades hold a tall gasket bead on a vertical or inverted flange. Choose from the application geometry. Hardness and modulus. Softer grades give better sealing compression set and vibration damping; firmer grades give more structural holding. Decide from whether the job is primarily sealing or bonding. Service temperature and environment. Match datasheet limits for temperature range, and for ozone, UV, and chemical exposure in outdoor or industrial service. Substrate adhesion. Silicone is selective. Confirm adhesion to the specific substrate, and use a primer where the datasheet calls for one. Many plastics need surface treatment. Thermal expansion. Silicone's flexibility usually absorbs expansion mismatch, but an aggressively cycled joint between very dissimilar materials can still fatigue. Our explanation of how CTE mismatch causes bond failure covers…

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June 8, 2024
Silicone

Silicone Conformal Coatings: Protecting Electronic Circuits

Circuit boards that run hot, cycle through wide temperature swings, or vibrate continuously need a coating that flexes rather than cracks. Silicone conformal coatings provide that: a soft, resilient film that seals against moisture and contamination while tolerating movement and heat that harder coatings cannot. What a Silicone Conformal Coating Is A silicone conformal coating is a thin polymer film, typically 50 to 200 microns thick, applied over a populated board. Silicone chemistry gives it a set of properties that distinguish it from acrylic, urethane, and epoxy coatings: Wide service temperature. Many grades operate from around -55 C to 200 C or higher, well beyond acrylic's range. High flexibility. A low modulus lets the film move with the board and its components without cracking or lifting. Vibration and shock damping. The elastic film absorbs energy that would otherwise fatigue lead wires and solder joints. Strong moisture resistance. Silicone blocks humidity and condensation and maintains high surface insulation resistance. Good dielectric strength. The film suppresses arcing and leakage between closely spaced conductors, including at altitude where air breaks down more easily. Advantages in Demanding Electronics Survives thermal cycling. Where a rigid coating would craze after repeated hot-cold cycles, a silicone film flexes and stays intact. Protects tall and heavy parts. The compliant film braces components against vibration without loading their solder joints. Handles hot boards. Power sections and boards near heat sources stay protected without the coating softening or embrittling. Reworkable in many grades. Silicone can be cut and peeled locally for component replacement, then re-coated. Cure Types Room-temperature moisture cure: one-part grades that cure on exposure to ambient humidity over hours. Simple to apply, no equipment beyond dispensing. Heat-accelerated cure: the same chemistry cured faster with a modest bake, useful for throughput. UV and dual cure: grades that fix in seconds under UV light, with a secondary moisture mechanism to finish shadowed areas. These support inline, high-throughput coating. Incure's Pyra-Sil silicone coatings span these options, including fast room-temperature grades that reach tack-free in minutes, grades that protect against moisture, UV, and high temperature on metals and plastics, and grades with a fluorescing tracer for inspection under blacklight. Grade selection is driven by cure method, film build, and the service environment. Email Us with your board's temperature range and vibration profile for a coating recommendation. Choosing the Right Coating Define the environment. Temperature extremes, thermal cycling rate, humidity, condensation risk, chemical exposure, and vibration all point toward or away from silicone. Silicone is the strong choice for wide temperature range and heavy vibration; it is a weaker choice where abrasion or aggressive solvent contact dominates, where urethane serves better. Set the film thickness. Thicker films give more protection and damping but take longer to cure through and can bridge fine gaps. Match build to the protection requirement. Confirm adhesion. The coating must bond to the solder mask, cured flux residues, and connector plastics on the actual board. Test with humidity and thermal-cycle exposure on a representative assembly. Account for expansion mismatch.…

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June 8, 2024
Silicone

Silicone Conformal Coating: Flexible Protection for Circuit Assemblies

A populated circuit board in the field faces condensation, salt fog, dust, vibration, and temperature swings that can short traces or corrode joints. Silicone conformal coating lays down a thin, flexible film that follows every component contour and keeps those hazards off the copper. What Silicone Conformal Coating Is Silicone conformal coating is a thin polymer layer, usually 50 to 210 microns thick, applied over a printed circuit assembly after soldering and cleaning. It falls under the "SR" class in IPC-CC-830, the industry qualification standard for conformal coatings. Unlike acrylic or epoxy coatings that dry to a hard shell, silicone stays rubbery across a wide temperature band, so it absorbs stress instead of cracking. Why Choose Silicone Over Other Coating Types Wide service temperature: many silicone coatings hold properties from about −55°C to 200°C, wider than acrylic or urethane. Stress tolerance: the elastomeric film flexes with thermal expansion of large or tall components and survives vibration without micro-cracking. Moisture and salt resistance: silicone is hydrophobic and maintains high surface insulation resistance under humidity, limiting leakage current and dendrite growth. Thermal cycling durability: the low modulus reduces the shear the coating imposes on solder joints as the board heats and cools, which matters given how CTE mismatch drives bond failure. The trade-offs: silicone can be harder to rework than acrylic, may need a primer on some laminates, and low-molecular-weight silicone can migrate and interfere with later bonding or electrical contacts if not controlled. Cure Chemistries Silicone conformal coatings cure by several routes. Condensation-cure grades react with atmospheric moisture and release a byproduct such as alcohol. Addition-cure grades use a platinum catalyst and are contamination-sensitive. Dual-cure grades combine UV curing for fast tack-free handling with a secondary moisture cure that reaches shadowed areas under components. UV-curable grades are typically cured under a UV LED flood lamp on an inline or benchtop station. Email Us with your board layout and environmental spec, and our team will help select a coating and cure method. Application Methods Dip coating: high throughput, uniform thickness, but requires thorough masking of connectors and test points. Spray, manual or automated: good control of coverage and thickness; selective spray systems coat only defined areas and skip keep-out zones. Brush: used for touch-up and low volume. Masking connectors, switches, and grounding pads is critical regardless of method. Boards must be clean and dry before coating, since trapped ionic residue or moisture under the film causes corrosion and loss of insulation resistance. Inspection and Common Defects Most conformal coatings contain a UV tracer so an inspector can verify coverage under a black light. Watch for these defects: delamination from contaminated or unprimed surfaces, incomplete cure in shadow areas of moisture-cure grades on dense boards, mealing or small bubbles from outgassing vias, orange peel from spraying too dry, and capillary bridging across fine-pitch leads. Cross-hatch adhesion tests and insulation resistance checks after humidity exposure confirm process quality. Thickness, Coverage, and Rework IPC-CC-830 and IPC-A-610 set a typical silicone coating thickness of 50 to…

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May 7, 2024