Oil-Soluble and Water-Soluble Lapping Fluid for Lapping and Polishing
Lapping Fluid is a lubricant used alongside diamond paste, diamond suspension and lapping pastes. It reduces friction between the lap and the workpiece, keeps the compound from drying out, helps stop the lap loading with debris and carries away lapping residue, so the abrasive keeps cutting evenly and the finish stays consistent.
It is available in two formulations, oil-soluble and water-soluble, each in 250ml and 1 litre bottles with a trigger spray or a 5 litre container. Both formulations are the same price.
Match the formulation to the compound. Lapping Fluid contains no abrasive; it must suit the carrier of the paste or suspension it is used with, or the compound will not work evenly. Check the compatibility table below before ordering.
Choose the Right Formulation
Choose the formulation that matches the compound you are using.
| Compound | Oil-Soluble Lapping Fluid | Water-Soluble Lapping Fluid |
|---|---|---|
| Diamond Paste | Yes | Yes |
| Diamond Suspension | No | Yes |
| Algalox | No | Yes |
| Ultra Lapping Paste | Yes | No |
Diamond paste works with either formulation, because its carrier is both water- and oil-soluble. Choose the water-soluble fluid where you want to clean parts and tools with water, and the oil-soluble fluid where you are already working with oil-based compounds.
| Size | Supplied In | Choose It For |
|---|---|---|
| 250ml | Bottle with trigger spray | Occasional use, or trying a formulation |
| 1 litre | Bottle with trigger spray | Regular bench use |
| 5 litres | Container (no trigger spray) | Workshop use and refilling smaller trigger bottles |
How to Use Lapping Fluid
Use a little, often.
A light film of fluid keeps the compound working; flooding the surface thins the abrasive and slows cutting.
- Apply the compound. Apply a small amount of paste or suspension to the lap, stick or tool.
- Add a little fluid. Spray or apply a small amount of the matching Lapping Fluid to the lap or work surface.
- Lap or polish. Work with a lapping stick, felt or wooden tool, lap or plate.
- Top up as needed. Reapply when the compound starts to dry or the lap begins to load with residue.
- Clean between grades. Clean water-soluble fluid off with water; remove oil-soluble fluid with a solvent such as Solvent Cleaner Spray. Keep a separate bottle or tool for each grade where practical.
Wear safety glasses and suitable gloves, and work in a well-ventilated area.
Compatible Compounds
| Product | Choose It When |
|---|---|
| Lapping Fluid | You need a lubricant for lapping or polishing compounds. Oil-soluble or water-soluble, in 250ml, 1 litre or 5 litres. |
| Diamond Paste | You are lapping or polishing very hard materials or need a mirror finish. Use either formulation. |
| Diamond Suspension | You need even diamond coverage on a lapping plate or larger flat surface. Use the water-soluble formulation. |
| Algalox | You are refining aluminium and soft non-ferrous metals. Use the water-soluble formulation. |
| Ultra Lapping Paste | You are lapping or valve grinding for flatness, fit and sealing. Use the oil-soluble formulation. |
Product Specifications
| Product type | Lapping and polishing lubricant |
|---|---|
| Formulations | Oil-soluble or water-soluble |
| Abrasive content | None |
| Sizes | 250ml and 1 litre with trigger spray; 5 litre container |
| Oil-soluble: use with | Diamond paste, Ultra Lapping Paste |
| Water-soluble: use with | Diamond paste, diamond suspension, Algalox |
| Clean-up | Water-soluble: water. Oil-soluble: solvent or degreaser |
| Unit of sale | Each |
| Delivery | Mainland UK only |
Need Help Choosing a Formulation?
Contact Moleroda with the compound you are using, the workpiece material and how you are lapping or polishing.

















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