Grease Compatibility: Can Different Greases Be Mixed?
Two greases cannot be considered compatible even if they are the same color or of the same NLGI grade. Grease compatibility depends on the thickening system, base oil, additive package, and application conditions.
Why does incompatibility occur?
When different thickening systems are mixed, the grease may become excessively soft, hard, or exhibit oil separation. These changes can lead to problems such as leaks, insufficient supply, or overheating in the bearing.
Base oil compatibility
Base oil technologies such as mineral, PAO, PAG, ester, silicone, and PFPE do not have the same chemical structure. Especially in specialized systems like PAG and PFPE, the transition procedure should be carried out according to the manufacturer's recommendations.
Laboratory compatibility test
In critical applications, different mixing ratios can be used to compare properties such as penetration, dropping point, mechanical stability, and oil separation. Field decisions should not be based solely on color or manual consistency checks.
How to exchange a product?
Where possible, the old grease should be removed as much as possible, and the lines and bearing clearance should be purged with new product. The amount of relubrication and the temperature should be closely monitored during the initial transition period.
Conclusion
Grease mixing should not be done without control. If compatibility is unknown, the safe approach is to remove the old product as much as possible and make a controlled transition to the new product.
For product selection, application evaluation, and technical support, you can contact GataMerk Industrial via info@gatamerk.com.
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