Product Partners

PRC-DeSoto Products

Aircraft fuel tank, fuselage, windshield, conductive and specialty sealants Industrial sealants and adhesives

Semco® Packaging and Application Systems

Innovative, clean, safe, and accurate packaging and dispensing solutions for single-and multi-component adhesives, sealants, encapsulants, coatings and lubricants

RPM Technology

Products for the removal of polysulfide (fuel tank) sealants and silicone sealants

eOx Cleaners

Aqueous based aircraft and industrial cleaners

Sealant Removal Wipes

Water wetted wipes for the removal of uncured sealants and adhesives

Glue Dots

Removable adhesive dots in a convenient dispenser box

SEMCO Model 250-A Sealant Gun

The Semco® model 250-A sealant gun is the standard of the aerospace and electronics industries. It is designed for quiet pneumatic application of sealants, adhesives, potting compounds, and other materials packaged in Semco disposable cartridges or Semkit packages for multi-component materials.

The Semco model 250-A gun is available with retainers to fit standard 32 cc, 59 cc, 156 cc, 214 cc, and 310 cc (1, 2.5, 6, 8, and 12 ounce) disposable cartridges. Air hoses to operate the gun must be ordered separately. The gun is constructed of durable metal and engineered plastic parts designed to withstand the rigors of the production work place. The nickel-plated retainers are affixed to the valve assembly via a quick connect, secure bayonet lock fixture permitting easy replacement of cartridges. For use in confined locations, the handle can be easily removed to allow more clearance and better manipulation.


Hose assemblies to fit the metal multi-axis swivel air fitting are available in 1.5-meter (5-foot) increments with Aro, Hansen, or Schrader air fittings attached. PRC-DeSoto International provides Semco brand precision molded cartridges, plungers, nozzles, Sem-Luer™ adapters, and Sem-Needles™. When these disposable plastic products are used in conjunction with the Semco model 250-A gun, the exact amount of material can be dispensed at the precise location required.


Attach the air hose assembly to the compressed air source. Some applications may require the user to replace the quick release hose connector with a fitting compatible with local air supply hardware. Unscrew the back knob and disengage the retainer from the valve assembly. Place the cartridge into the retainer and replace the loaded retainer onto the valve assembly. Tighten the back knob until snug. When the trigger is depressed, air pressure pushes against the plunger in the cartridge. This allows for positive, even dispensing of the material.

The material continues to flow until the trigger is released, thereby permitting a drop, shot, or bead to be accurately applied. The amount of material dispensed is determined by the viscosity of material, airline pressure, nozzle or needle orifice size, and length of time the trigger is depressed. When all the material has been dispensed from the cartridge, loosen the retainer by unscrewing the back knob. Remove the disposable cartridge and nozzle. Dispose of leftover material in accordance with local regulations and instructions on the material safety data sheet.


  • Reduces applied material cost.
  • Provides accurate material control.
  • Lightweight.
  • Handle can be removed to facilitate application in confined areas.
  • 0-6.9 bar (0-100 psi) operating range.
  • Available in 32 cc, 59 cc, 156 cc, 214 cc, and 310 cc (1, 2.5, 6, 8, and 12 oz.) sizes.
  • Bayonet lock on retainer permits quick cartridge change.
  • Durable, shock resistant parts.
  • Touch control on trigger regulates flow.
  • Positive control for smooth, even dispensing.
  • Ergonomic design.
  • Quiet operation.

Model 250-A Semkit Gun

Technical Data Sheet (pdf) on the Model 250-A Gun

For more information about these products contact Bergdahl Associates, Inc.