Troubleshooting

Problems	Probable causes	Possible solutions
Scratches	-Sharp abrasive particles are released from the material being used to grind orpolish. -Contamination of the previous steps in grinding or polishing.	-Repeat the step until all scratch lines are uniform. -Increase the preparation time for the current step. (Not the pressure) -Verify that the cutting edge of the abrasive being used is effective. If necessary, change. -Change polishing cloth. Use a more thorough technique in cleaning between steps. -Clean samples thoroughly in between each step.
Short wheel life	- Wheel is wearing down too fast.	-Select the harder wheel. -Reduce applied cutting pressure.
Wheel not cutting	- Slow wheel breakdown.	-Reduce coolant rate. -Choose a harder or softer wheel. -Use swaying stroke.
Burning of a sample.	-Incorrect cutting fluid. -Insufficient coolant. -Improper Cut off-wheel. -Excessive force applied	-Increase coolant rate. -Check for the proper direction of the coolant. -Reduce applied cutting pressure. -Select a softer wheel.
Curved cut.	-Excessive cutting force applied.	-Reduce applied cutting pressure. -Clean hoses thoroughly of all residues.
Non-uniform wheel wear.	-Flow of coolant is not uniform.	-Clean hoses from cutting debris.
Motor stalling.	-Sample being cut is too large.	-Decrease sample size.
Excessive blade wobble	-Excessive initial force applied. -Missing blotters.	-Reduce applied cutting pressure. -Insert blotters.
Burr formation	-Excessive vibration. -Excessive initial force applied. -Missing blotters.	-Reduce applied cutting pressure. -Insert blotters.
Specimen chipping.	Too large in abrasives.	Use a finer grit wheel.

Problems	Probable causes	Possible solutions
Shrinkage	- Poor adhesion to sample surface.	- Decrease molding temperature. - Cool mount before ejecting sample.
Mold cracking	- Powders absorbed moisture. - Entrapped gases during molding. - Sample too large for mold area. - Samples have sharp corners. - High internal stress due to rapid cooling.	-Preheat powders. -Release pressure for a moment during the flow stage. -Reduce the size of the specimen. -Clearance between sample and mold should be approx. 1/8". -Reduce specimen size. -Allow mounts to cool more slowly.
Top die damaged	-Not enough mounting powder added.	- Add sufficient mounting powder.
Mold blistering	-Not enough applied pressure. -Curing time is insufficient.	-Increase pressure and curing time.
Mounts are sticking to mold cylinder	- Mold temperature is too high.	- Reduce molding temperature. - Apply releasing agent.
Staining and dull surfaces	- Mold temperature is too high	- Reduce molding temperature.
The color of dye in the mount bleeds while rinsing in alcohol.	-Molding temperature is too low. -Insufficient curing time.	-Verify temperature and adjust if necessary. -Increase curing time.
Unfused mount	- The Molding temperature too low. - Insufficient curing time.	-Verify temperature and adjust if necessary. - Lengthen curing time.
Cotton ball effect	-The molding temperature has not reached the required maximum. -Polymerization time is insufficient.	- Verify temperature. Adjust if necessary. - Increase curing time.

Problems	Probable causes	Possible solutions
Air entrapment	- Agitation of blend between resin and hardener is too rapid. - Improper degassing of the specimen	- Gently blend the resin and hardener. The alternative is to use a pressure vessel or vacuum system.
Mold cracking	- The proportion of resin and hardener is incorrect. - Insufficient air cure. - Oven curing temperature is too high.	-The reaction between the resin and hardener is too exothermic. -Measure accurate proportions of resin and hardener.
Mounts are soft	-An incorrect proportion of resin and hardener was used. -Poor mix between resin and hardener.	-Increase hardener proportion to resin ratio. -Homogenize more thoroughly the mixture of resin and hardener.
Mounts sticking to mold	- Mold temperature is too high.	-Use a mold release agent. -Decrease the volume of hardener.
Staining and dull surfaces	- Incorrect proportion of resin and hardener. - Oxidized hardener.	-Measure accurate proportions of resin and hardener. -Seal the hardener container.
Top of mounts sticky	- An Incorrect proportion of resin and hardener. - Poor mix between resin and hardener.	-Measure accurate proportions of resin and hardener. -Homogenize more thoroughly the mixture of resin and hardener.
Poor adhesion between resin and specimen	- Not using the appropriate medium for mounting specimen. - Samples were not cleaned before mounting the sample. - Mounting shrinkage.	-Clean samples thoroughly before mounting the sample. -Use a mounting medium that has good adhesion and no shrinkage.
Time for polymerization is too long.	-An incorrect proportion of resin and hardener. -Exothermic temperature is too low. -Oven polymerization temperature is too low.	-Measure accurate proportions of resin and hardener. -Homogenize more thoroughly the mixture of resin and hardener.

Problems	Probable causes	Possible solutions
Scratches.	-Sharp abrasive particles are released from the material being used to grind or polish. -Contamination of the previous steps in grinding or polishing.	-Repeat the step until all scratch lines are uniform. -Increase the preparation time for the current step. (Not the pressure) -Verify that the cutting edge of the abrasive being used is effective. If necessary, change. -Change polishing cloth. Use a more thorough technique in cleaning between steps. -Clean samples thoroughly in between each step.
Smearing/Buffing	-Surface of the specimen is not being cut. -The pH of the alumina suspension is too high.	-Increase the quantity of applied lubricant. -Use a less napped cloth. -Use a coarser diamond grain particle. -Decrease the pH of alumina suspension.
Staining	-The pH of alumina suspension is alkaline -Mounting does not adhere to the specimen. -Incomplete penetration of cracks or pores.	-Neutralize the pH of alumina suspension. -Select resin with little or no shrinkage. -Use pressure vessels or vacuum systems.
Grain Pullouts.	-Insufficient steps between grain sizes. -Type of polishing cloth used. -Polishing time is too long or too short. -Excessive use of lubricant.	-Increase grain size steps. -Use a napless polishing cloth. -Decrease the polishing time. -Depending on the application may have to increase the polishing time. -Reduce the quantity of lubricant used. -Moisten cloth with lubricant before applying diamond abrasive.
Rounding of the edges.	-Samples were not mounted. -An incorrect mounting medium was used. -Polishing times were too long. -Excess pressure was applied to the specimen. -Type of polishing cloth used.	-Mount the samples. -Use a mounting medium that has good adhesion. -Keep polishing time to a minimum. -Use shorter and tighter weaved polishing cloth.
Polishing relief.	-Too much speed. -Excessive rotation. -Mixing different hardness of materials while polishing.	-Reduce speed. -Use a lower fiber-napped polishing cloth.
Cracks.	-From cutting the specimen. -Clamping of the sample. -The wrong mounting medium was used. -Shrinkage.	-Use the appropriate cut-off wheel. -Use a protective layer between the sample and clamp from cut-off equipment. -Use a cold mounting system with a vacuum system or pressure vessel. -Use a mounting medium that has the least shrinkage properties.
Porosity.	-Worn out abrasive. -Type of polishing cloth used. -Type of mounting medium.	-Change abrasive discs more often. Alternatively, use diamond discs. -Use a shorter nap polishing cloth. -With cold resin, use vacuum or pressure vessel systems.
Embedded abrasive.	- Excess pressure was applied to specimen. - Type of polishing cloth used. - Excessive use of polishing abrasive. - The lubricant has low viscosity.	- Reduce pressure applied to specimen. - Use a shorter nap cloth. - Decrease the amount of polishing abrasive, especially for soft metals. - Use a higher viscosity lubricant.
Comet tails.	-Too much pressure. -Too much speed. -Over-polishing on worn grinding cloths. -Use of the same orientation during all polishing steps. -Scratches from embedded abrasives.	-Reduce pressure applied. -Reduce speed. -Change the grinding cloth more frequently. -Change the orientation of the sample for every step. -Use the same direction in rotation for the head and base.
Scratch lines are long and dull.	-Sharp abrasive particles from the material being used to grind or polish. -Contamination of the previous steps in grinding or polishing.	-Repeat the step until all scratch lines are uniform. -Increase the preparation time for the current step. (Not the pressure). -Verify that the cutting edge of the abrasive being used is effective. -Change polishing cloth. Use a more thorough cleaning technique between steps. -Clean samples thoroughly in between each step.
Machine vibration.	-Too much pressure. -Speed is too low.	-Reduce pressure applied. -Increase grinding speed.
Uneven grinding across the specimen and mount.	-Inappropriate choice of resin for the sample to be prepared. -Improper tracing of the specimen over abrasive discs. -Different head/base speed.	-Select a resin that is comparable to the hardness of the sample. -Orienting is the hardest part of the sample to cover the abrasive discs. -Match head/base speed.
Gaps	Mounting does not adhere to the specimen.	-Select a very hard resin that has good adhesion, is wear-resistant and has low shrinkage. -Clean sample. -Select resin with little or no shrinkage. -Use a pressure vessel or vacuum system.