This page tries to explain the different adhesives you use when building a helicopter.

The TREX 500 ESP kit came with three bottles:

  • Bottle – T43 – Blue – thread lock for screws & metal parts.
  • Bottle – R48 - Green – Anaerobics Retainer or Tubular adhesive (e.g. bearings).
  • Tube – Oneway Bearing Grease – Model # BG71040 – 3cc

Thread Lock Glue (a.k.a Loctite)

You need a special glue to keep screws from vibrating loose during flight.  This glue is called thread lock glue.  However, most people use the name of a commercial product called Loctite or Holdtite.

Visit showing how to apply it.

A colour code is used to distinguish the three strengths of Loctite.  These are metal-to-metal fasteners:

  • RED – Loctite Threadlocker RED 271 Permanent.
    • Use on internal bolts.
    • This is permanent, but removes with heat & tools.
  • BLUE – Loctite Threadlocker Blue 242 Removable.
    • This can be removed using hand tools, no heat required.
    • Align provided the bottle Blue T43 for threads.
  • GREEN - Loctite Threadlocker GREEN 290 Penetrating.  Same as BLUE 242, but applied to nut-bolt seam AFTER assembly.
    • Removes with hand tools.
    • Recommended to heat for 15 seconds.   Use a soldering iron placed on the head of the scew.
    • Do not use Green for screws since you will not be able to break it loose for repair.    For this reason, a lot of people don’t recommend using it.
    • Align provided R48 bottle for pinions and bearings.

Cyanoacrylate Glues (CA Glue)

Cyanoacrylates, commonly referred to as “CA”, are moisture-activated adhesives stabilized with acids. Water overpowers the small amounts of acid found in the CA, so that when CA is applied to a part, moisture from the surface of that part and from the atmosphere cause the CA to form a solid, or bond, in seconds.

These glues have a ‘best-before-date’, so don’t buy in large quantities.

Cyanoacrylate Glues (CA) comes in different viscosities: CA, CA+ and CA-.

Separately, I purchased separately the following 1/2 ounce (14.2g) bottles of Cyanoacrylate Glue (CA) from Great Planes website ( :

  • Thin Instant Set CA- Green  - Great for tight fitting parts.  Cures in 1-3 seconds.  Part # GPMR6001
  • Medium CA+ Gap Filling – Yellow – General Use.  Cures in 10-15 seconds.  Part # GPMR6007

Visit for a good explanation.

CA is cheaper when you buy it in larger quantities, but it doesn’t last forever, so buy what you think you will need. You can extend CA glue shelf-life by storing a tightly-sealed bottle in the refrigerator.