Trouble shooting-Hot mounting
1. Radial Cracking
Cause:
Insufficient distance between specimen edge/corner and cylinder wall, or specimen has sharp corners.
Solution:
Increase cylinder diameter or reduce specimen size. The distance between the specimen and the cylinder wall must be a minimum of 3 mm to avoid cracks in the resin. This is especially critical for specimens with sharp corners.
2. Shrinkage
Cause:
Incorrect choice of resin.
Solution:
Re-mount a new specimen using a resin with a lower linear shrinkage value.
3. Blistering
Cause:
Insufficient heating time.
Solution:
Increase heating time, or increase process temperature.
Cause:
Over-cured surface.
Solution:
Decrease process temperature.
4. Bulging
Cause:
Insufficient cooling.
Solution:
Increase cooling time.
5. Porosity
Cause:
Excessive temperature.
Solution:
Reduce process temperature.
6. Voiding within Large Mounts
Cause:
Insufficient heating time.Excessive temperature.
Solution:
Increase heating time.Reduce process temperature.
7. Dull Surface Finish
Cause:
Insufficient heating time.
Solution:
Increase heating time.
8. Adhesion between Mount and Rams
Cause:
Insufficient application of mould release agent.
Solution:
Apply mould release agent. This must always be applied to the mounting rams as a thin layer before the mounting process begins. This prevents the resins from sticking to the rams and makes it easier to remove the mounts afterwards.
9. Individual Grains Visible on Mount*
Cause:
Resin has cured without force/pressure.
Solution:
Increase force/pressure during heating cycle.