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PPG Semkit Mixing

There are a number of official methods approved for mixing PRC or Pro-Seal sealants packaged in Semkits including mixing by hand, mixing with a Semco Model 1088 Automated Semkit Package Mixer and mixing with a Semco Model 285-A Portable Electric Semkit Package Mixer.

All other mixing methods are not authorized by the formulator and may result in issues with the material's application and performance properties.  

PPG Semkit Mixing

The mixing of a Semkit®️ by other means, such as with a drill adapter, may compromise the performance properties of the sealant and void the warranty.

When mixing a PPG Aerospace sealant Semkit®️, always follow the directions as dictated on the product packaging. The recommended mixing instructions are tested and validated to ensure that the sealant performs as intended and meets all specification requirements.

Instructions are provided for hand mixing (including Semco Model 285 mixer), or for automatic mixing with a Semco Model 388, Model 1088 or Model 1188 machine mixer.

Machine mixing and hand mixing are the only industry recognized methods for mixing sectionalized containers (Semkit®️) as referenced in SAE AIR4069 and Boeing BAC5000. 

Mixing outside of these controlled and validated procedures has the potential to alter the sealant performance or even damage the sealant itself.

Testing shows that mixing with a drill adapter has several definitive detrimental effects on the sealant: Uncontrolled mixing speed will excessively heat the sealant and greatly reduce the working time of the sealant, and will decrease the extrusion rate below specification-required values. The high torque and shear induced with a drill may also damage certain raw material ingredients in the uncured wet sealant, irreversibly degrading the anti-sag properties of the wet sealant, or the density of the cured sealant.

Low density sealants are especially affected by drill mixing. Any of these negative effects may cause the sealant to perform outside of specification requirements,

and will therefore void the certification and/or warranty. Mixing with a drill adapter also presents significant safety concerns, as there have been documented cases of user injury when mixing a Semkit ®️ with a drill.

Semkit in a hand

Hand Mixing of Semkits

Mixing by hand is an approved method for mixing PRC and Pro-Seal sealants packaged in Semkits. For detailed written instructions, please contact our technical service team or watch the brief videos below on how to mix an injection-style Semkit or a barrier-style Semkit by hand.

Semkit video showing machinery
Hand mixing video

Semco Model 1088 Automated Semkit Package Mixer

The Semco Model 1088 Semkit Package mixer provides complete automatic mixing of filled Semkit Packages.

Use of the mixer will minimize operator set up of the machine for different kit configurations, reduce worker fatigue, and assures the user a more thorough and consistent mix, kit to kit.

Technical Details:

  • Door composed of Lexan (PC)
  • Slide plate and cap assembly composed from Delrin (Acetal)
  • Minimum 3 cfm
  • Operating requirements: 75 to 90 PSI
  • Dry shop air required
  • Unloaded Spindle = 100 RPM
  • High torque motor for thick materials

Semco Model 285-A Portable Electric Semkit Package Mixer

The Semco Model 285-A Semkit package mixer provides semi-automatic mixing of filled Semkit packages. Use of the mixer reduces worker fatigue and assures a more consistent, uniform mix.

The drive spindle rotates the mixing rod while the operator strokes the cartridge vertically. This permits the rotating dasher to thoroughly mix the materials. The bell timer alerts the operator when the mix cycle is completed.

PPG Mixing machine range