# Body and sheet metal Seam sealers for body panels, doors and container joints — sandable, paintable, four colours. Body and sheet metal sealant family. [KA540 ### Automotive Sheet Metal Adhesive High-modulus seam sealer for body panels, sandable and paintable.](https://karmindadhesive.com/products/ka540-sheet-metal-adhesive/) ## Choosing one KA540 is a sealer, not a structural adhesive. The 600% elongation and 2.5 MPa are chosen so the bead follows a flexing panel and still sands and takes paint. Where the OEM drawing calls for a panel bond, the product class is different and the bond line is 0.2–0.5 mm, so do not substitute. ## Where it goes wrong The two rework cases that cost most are a bead applied over e-coat without scuffing, and a sealer sanded before it has cured. The first lifts at the edge after paint; the second tears and leaves a step in the finish. Both are surface and schedule, not product. The 2.5 MPa and the 600% are a pair. Read alone, 2.5 MPa looks weak next to a structural adhesive at 20 MPa; read as a sealer, it is the point: the bead has to move with the panel and still sand and take paint. ## Decision table | If | Then | Because | | The seam will be sanded and painted | KA540 | 600% elongation, sandable, takes a topcoat | | The OEM drawing calls for a panel bond | not this class | a 0.2–0.5 mm bond line needs a structural adhesive | | Container or trailer seam | KA540 or KAM921 | movement in the joint versus UV on the outside | | Interior floor seam | KA540 | flexible under foot traffic and paintable | ## Read before you specify - [where a sealer belongs on a body](https://karmindadhesive.com/resources/body-seam-sealer-guide/) - [the 1,500x stiffness difference](https://karmindadhesive.com/resources/seam-sealer-vs-structural-adhesive/) - [what a topcoat needs from the bead](https://karmindadhesive.com/resources/painting-over-seam-sealer/) Send the seam type, substrate and whether it will be painted, and we will confirm sealer or structural. [martin@karmindadhesive.com](mailto:martin@karmindadhesive.com) ## Other families - [Automotive glass bonding](https://karmindadhesive.com/products/automotive-glass/) — Windscreen, side and rear glass adhesives — 310 ml cartridges, sausages and 200 L barrels. - [Construction joints](https://karmindadhesive.com/products/construction/) — Concrete, tunnel and drainage sealants — 550–615% elongation, elastic recovery up to 80%. - [Industrial and STP](https://karmindadhesive.com/products/industrial/) — Silyl-terminated polymer sealant for metal, plastic and glass — primerless and paintable. - [Wood and glulam](https://karmindadhesive.com/products/wood/) — One-component PUR for engineered timber, glulam beams and sandwich panels. - [Activators and primers](https://karmindadhesive.com/products/accessories/) — Surface preparation that decides whether the bead holds: K-901 activator, K-801 primer.