CTA Adhesive Paste

CTA505 Adhesive

COMPOTOOL CTA505 Adhesive is a two component high temperature thermally stable adhesive that bonds the Compotool High Performance Tooling Boards.

Key Features:

  • High temperature resistance

  • Low odour

  • Matched hardness

  • Non-contaminating

Technical Information:


CTA505 Adhesive Part A

CTH905 Adhesive Hardener Part B


Creamy Off-white liquid



Estimated Coverage Mixed

2L / 4kg per 1m2 (2 US Quarts per 10 ft2)

Bond Joint Thickness

Between 0.5mm and 3mm (.020’’ and .125’’)

Shelf Life

12 months

Maximum Use Temperature

250ºC (480ºF)


  • Keep sealed when not in use. Previously opened cans have a reduced shelf life

  • Keep away from sources of ignition

  • Store in a cool dry place and protected from frost

Board Preparation:

  1. For high strength structural bonds pre-fit Compotool blocks to insure the tightest bond joints and eliminate uneven gaps.

  2. The surface of the COMPOTOOL board should be clean, dry and dust free. With a dry, oil-free air line dust off the surface. (At no other time during the COMPOTOOL process do we advise the use of an air-line).

  3. Densify the surface with 10 generous coats of COMPOTOOL CTD003 Densifier. COMPOTOOL CTA505 Adhesive can be applied to wet coats of COMPOTOOL CTD003 Densifier. No sanding is required between COMPOTOOL CTD003 Densifier and the application of COMPOTOOL CTA505 Adhesive.

Mixing Ratios:

IMPORTANT! Prior to mixing the two components be sure to thoroughly stir the CTH905 as contents may have settledin storage

CTA505 Adhesive Mixing Ratios

Specific Gravity

Parts by Weight

CTA505 Adhesive – Part A



CTH905 Adhesive Hardener – Part B



Example i.e 1kg or 2.2lb of Part A with 1kg or 2.2lb of Part B by weight

Thoroughly blend the two parts until completely mixed. The work life of 100oz of mixed material at (73ºF) 23ºC isapproximately 2 hours. Smaller masses and or higher temperatures will shorten work life.

CTA505 Adhesive – Trowel on Application:

  1. For large shapes Compotool recommends the use of a base plate to block up on. Apply a layer of COMPOTOOL PTFE ToolFace between the base plate and the Compotool blocks. The use of unattached locator blocks are recommended. Do not glue or bolt the block up to the base plate due to differential thermal expansion between the base plate andthe block up.

  2. With a trowel or brush, generously apply the thoroughly mixed CTA505 Adhesive to both sides of the board. Bond joint thickness of between 0.5 and 3mm (.020’’ and .125’’).

  3. Join the boards and secure until adhesive sets. Boards can be secured via clamps or vacuum bag. Setting time is approximately 24 hours at room temperature.

  4. Prior to machining, post cure the block up at 180ºC (350ºF) for 1 hour. Allow enough time for the block up to come up to temperature. This may take several hours.


Compotool CTA505 is sold in pack of both Part A and Part B together.

COMPOTOOL CTA505 Adhesive Part A

5L (1.3 US Gallons) 9kg / 19.8lb Containers

COMPOTOOL CTH905 Adhesive Part B

4L (1US Gallons) 9kg / 19.8lb Containers


  1. Application of COMPOTOOL products should be performed in a well-ventilated area. The COMPOTOOL board must be clean and dry before use.

  2. The COMPOTOOL CTA505 Adhesive is sensitive to variations in application technique and thickness. It is important that the user carries out their own test and trials to determine how thick they can apply the adhesive. Mould configuration, room temperature and humidity will influence the cure time from that detailed above.

PHONE +64 (09) 573 1970    FAX +64 (09) 573 1973