URE-FIL™ 19 *NOTE: Product Packaging May Vary

Technical Bulletin and SDS

URE-FIL™ 17 & 19 pure aluminum pellet fillers can be used with Smooth-On® liquid epoxy and urethane resins to improve thermal conductivity, dimensional stability, reduce shrinkage in large mass castings, etc. These fillers can also be used to add evenly distributed weight to metal cold-castings and to create artistic casting effects.

URE-FIL™ 19 are large grain aluminum pellets (1200 micron). Larger grain pellets will not fill areas of high detail as well as the smaller grain pellets but both pellet sizes can be used together for more uniform filling.


  • Can be added to aluminum-filled urethane and epoxy resins for vacuum forming applications to increase thermal conductivity (even heat distribution) when casting parts for applications with higher temperature requirements.
  • Will add evenly distributed weight to metal cold-castings to simulate the feel of solid metal reproductions at a reduced expense compared to metal foundry castings.
  • Will lower exothermic (heat) temperatures during cure cycle (see chart on reverse side), which reduces the shrinkage rate resulting in improved dimensional stability in large mass castings.
  • Can be added to liquid urethane and epoxy resins to create metallic visual effects when used with clear and colored liquid plastics.
  • When fully cured, resin filled with URE-FIL™ 17 & 19 can be cut, drilled, turned and machine tooled.
  • Should not be used as fillers in RTV rubber products.


URE-FIL™ 17 & 19 pellets are recommended for use with Smooth-On® liquid epoxy and urethane resins. Pellets need to be thoroughly dispersed into the resin so that they are completely encapsulated. In order to reduce splashing during the mixing process: 1. Dispense pellets into a mixing container, 2. Dispense Parts A + B of resin and mix together thoroughly in a separate container, 3. Pour resin mixture onto dispensed pellets and stir together thoroughly.

Note: Pellets are sharp and should not be handled by bare hands. Exposed pellets can damage/abrade mold surfaces. Therefore, to maximize mold life, pour or brush a gel/face coat layer onto mold surface prior to casting. Allow gel/face coat layer partially cure before backfilling with resin/pellet mixture.

Mix Ratio for Using with Unfilled Resins (by Weight or by Volume):
1 Part Mixed Resin (A + B) + 2 Parts Filler

Mix Ratio for Using with Aluminum Filled Resins (by Weight):
1 Part Mixed Resin (A + B) + 1 Part Filler

Related Categories: Urethane Resins, Colorants, Paints & Fillers

Related Series: URE-FIL™ – Powder Fillers, Urethane Resin Accessories – Take Your Urethane Resin Further