by Douglas Craig, Technical Application Engineer & Collision Industry Liaison, Structural Adhesives Tech Service, LORD Corporation
A collision repair shop technician’s goal is to restore a damaged car to its pre-accident condition, which fulfills both OEM and safety requirements and satisfies the customer. To return a damaged vehicle to its “as-built” condition, repair shops need to use materials that are equivalent to those used in the original manufacture.
Repair seam sealers and foams can be used in vehicle repair to duplicate the look and performance of original OEM parts.
While it is not possible to exactly duplicate the seam sealers and foams used in OEM production, the repair products that are available will produce equivalent results. This is apparent with two-component seam sealers and foams used for repair vs. one-component OEM products. Different types or formulations of repair products can still provide the same outcome.
Car manufacturers use seam sealers and foams to control noise, vibration and harshness/corrosion (NVH) almost anywhere in a vehicle body. OEMs primarily use one-component products which cure during the e-coating process. However, two-component products sometimes are installed in the paint shop after curing the e-coating.
Typically, two-component seam sealers and foams are used in the repair process, since the heat system needed to cure a one-component material is not feasible for a repair shop. Two-component products/materials allow the repair technician to achieve the same quality or characteristics that are evident in the component being repaired.
Here is how OEMs use seam sealer and foam products in vehicle production:
- Noise control – Foams eliminate air movement in the auto-body shell; when air movement is curtailed, noise is reduced.
- Sound and vibration dampening – LASDs (Liquid-Applied Sound Deadeners) are used to dampen vibration and noise in floor panels, vehicle underbodies and inner cabins.
- Harshness – Sealers and foams are used to provide a “smooth” ride for the driver and the passenger by eliminating air gaps that can lead to a “bumpy” ride
- Corrosion protection – Specially formulated sealers and foams are used to prevent various car parts from corroding.
Look for Part 2 on seam sealers and foams for collision repair, “Understanding repair product selection for seam sealers and foams in collision repair.”
For a video on using seam sealers in collision repair, click here.