MS polymer sealant is a flexible material used where window frames, wall panels, metal, stone, and painted finishes meet. Some products mainly close gaps that open and close, while others can also glue parts together. Many can be painted, but the family name alone does not show which surfaces, weather, amount of movement, or paint the exact product can handle.
Moving gaps that may also need a painted finish
MS polymer sealant can work around windows, panels, metal, stone, and the edges between finishes when you can identify both surfaces, estimate how far the gap may open or close, and check the exact paint and weather exposure before installation.
- Window edges and panel gaps that need to remain flexible as the materials on either side move
- Projects that need paint over the finished line and can test the exact sealant-and-paint combination first
- Sites that can measure the gap, identify both surfaces, and state how each location will be filled, cleaned, and dried
Do not use one line of sealant as a repair for a failed bathroom waterproof layer or a structural crack. For mirrors, natural stone, and large glass, first confirm that the exact product allows that use and test a small area.
- The work expects the sealant to replace a waterproof layer or repair structural movement
- The surfaces are wet, dusty, oily, or loose and cannot be cleaned and dried before application
- Stone, mirror backing, plastic, or painted finishes are involved but bonding and staining cannot be tested
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Start with the gap, not the MS label
Two products labeled MS polymer can harden to different levels, stretch by different amounts, and stick to different surfaces.
- How much will the gap move?
- A window edge, exterior panel gap, and interior trim line do not move by the same amount. Match the measured width and depth with how far the exact product can stretch or compress and how soft it remains after hardening.
- What are the two surfaces beside the gap?
- Write down metal, concrete, painted board, plastic, stone, glass, or another finish on each side. Then confirm how each side must be cleaned, whether a first coat is required, and whether a small test is needed to check sticking or staining.
- When and how will it be painted?
- Paintable does not mean every paint will dry and move correctly over every product. Test the exact paint after the sealant has hardened for the required time, then check for tackiness, cracking, or color change.
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Compare real products
These modified-silicone and MS-polymer examples come from official manufacturer pages. A product for moving window or façade joints and one for elastic bonding can differ in firmness and stated use, so decide whether the job is sealing a joint or bonding parts before comparing names.
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| Market | Product | What it is | Official page |
|---|---|---|---|
| Korea | KCC SILICONEMS1000 | A single-part product for window perimeters and joints between aluminium or composite panels. If it will be painted, test the actual paint system after the product has fully hardened for the time stated by the manufacturer. | Open |
| Japan | セメダインPOSシール | A single-part product for a range of interior and exterior wall joints that can be painted. Check whether the two surfaces require separate preparation before application. | Open |
| United States | BostikPRO-MS 50 | A low-modulus construction product for vinyl window perimeters, fibre-cement board and exterior trim joints. Check its stated United States uses and how each surface must be cleaned before application. | Open |
| Korea | BostikISR 70-03 | A silyl-modified polymer product for elastic bonding and sealing of transport-equipment parts. Its industrial assembly role differs from a building-joint sealant, so compare it only within that stated use. | Open |
| Japan | コニシボンド MSシール | A two-part product for painted joints in metal or precast-concrete curtain walls and other panels. Its official page excludes gaps used to hold glass in place. | Open |
| United States | HenkelTEROSON® MS 939NA | An industrial adhesive-sealant for elastic bonding and sealing of metal, glass and selected plastic parts. Do not substitute it for a façade-joint product without checking the actual parts and surface trials. | Open |
A single-part product for window perimeters and joints between aluminium or composite panels. If it will be painted, test the actual paint system after the product has fully hardened for the time stated by the manufacturer.
A single-part product for a range of interior and exterior wall joints that can be painted. Check whether the two surfaces require separate preparation before application.
A low-modulus construction product for vinyl window perimeters, fibre-cement board and exterior trim joints. Check its stated United States uses and how each surface must be cleaned before application.
A silyl-modified polymer product for elastic bonding and sealing of transport-equipment parts. Its industrial assembly role differs from a building-joint sealant, so compare it only within that stated use.
A two-part product for painted joints in metal or precast-concrete curtain walls and other panels. Its official page excludes gaps used to hold glass in place.
An industrial adhesive-sealant for elastic bonding and sealing of metal, glass and selected plastic parts. Do not substitute it for a façade-joint product without checking the actual parts and surface trials.
Official pages checked 2026-08-24 · Recheck pricing and availability at the linked page.
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Plan the two surfaces and the paint together
When sealant and painting are priced by different workers, the quote should name who will test the sealant and paint together before the full area is finished.
- List both surfaces, how far the gap may open or close, its width, and its depth at every window, panel, and edge between finishes.
- Include removal of old material, the round filler behind deeper gaps, cleaning and drying both sides, masking, and any first coat required by the manufacturer.
- Use a small test area on stone, mirrors, plastics, factory finishes, and painted surfaces to check whether the sealant sticks or leaves a stain.
- Name the paint, earliest painting time, weather protection, temperature, and humidity in the quote. Also state who will apply and check the small test patch before the full area is painted.
You can also compare silicone sealant, review window replacement, or browse another material.
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Watch the bonded edges first
Failure often starts where the sealant pulls away from one side rather than in the middle of the visible line.
- Inspect lifted edges, surface cracks, staining, sections squeezed too flat, and gaps stretched far beyond their original width.
- Before repainting, test a small section for cracking, tackiness, staining, or poor drying over the existing sealant.
- For replacement, review the old filler and how far the gap opens and closes as well as the sealant. Repeated failure may mean the gap was shaped incorrectly or the product could not stretch far enough.
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