Shims

Moldable shim materials eliminate gaps and differences in composite and metallic assemblies. They act as both an adhesive and a shim.

Shims

Do you want to reduce production time in aircraft assembly? Liquid shim materials can do just that, plus increase profitability for equipment manufacturers and improve worker safety.  

Commonly used in aircraft manufacturing in rib-to-skin assemblies, liquid shims are typically applied* over the surface to be joined (usually the rib edge), followed by assembly of the parts. The liquid shim is squeezed between the parts prior to bolting together. This process forces any excess shim material out, leaving just the right amount of shim necessary to bridge any gaps that occurred during the manufacturing process.

What are the key features to look for when selecting a liquid shim material? Cure time, compressive strength, resistance to cyclic fatigue and optimal viscosity for when application is on a vertical surface. Longer cure times allow time for large component assembly and help in the clean-up of unused material. However, very long cure cycles may interfere with production flow.

Why choose Socomore’s DMS-4-828? DMS-4-828 is a two part epoxy shim material that meets the fast-curing and high-strength requirements needed when filling gaps in metallic and composite assemblies. It is available in liquid and as pre-mixed calendered sheets that can be adapted to meet different thickness requirements and die-cut into specific shapes. The sheets can be easily stored frozen, inhibiting the cure process, until needed. After a rapid thaw process, the materials progress through the normal room temperature cure cycle.

SOCOMORE DMS-4-828

What are the key features of DMS-4-828?

  • Fast curing at ambient temperature (that can be accelerated by mild heat)
  • Fluid resistance: fuel, water ingress
  • Good gap filling properties
  • Excellent adhesion and compression properties
  • Extrudable from cartridges or bulk material
  • Thixotropic – Low slump: low flow on vertical surfaces
  • Low exothermicity  
  • PMF sheets for easy and fast application

*Use a release agent prior to the application of the shim if the assembly will be inspected. This allows the shim to cure after squeeze-out and gives the ability to remove the skin or rib side to see if any gaps exist.

 

Our dedicated R&D is working on a lot of projects regarding shims & sealants. If you’d like to know more, don’t hesitate to contact us.

 

Shims selection