How to Improve Paint Fineness: 5 Practical Tips
Paint fineness (also called grind gauge or Hegman gauge) is one of the most important quality parameters of paint. If your paint fineness is too high, you'll get a rough finish, low gloss, and poor hiding power. But how do you improve it? In this guide, we'll share 5 practical tips that will help you get much better fineness.
1. Tip #1: Use More Dispersant
This is the #1 reason people can't get good fineness. Not enough dispersant means the pigment particles stick back together immediately after you break them apart. Use 2-5% dispersant based on pigment weight. For difficult pigments like carbon black, you might need up to 8%.
2. Tip #2: Mix Longer
Most people stop mixing way too early. Pigment dispersion takes time — 20-30 minutes of high-speed mixing is standard. If you need very fine paint (Hegman 7+), you might need 45 minutes or even a bead mill pass. Check the fineness every 10 minutes with a Hegman gauge — don't just guess.
3. Tip #3: Use a Bead Mill
A high-speed disperser is great for regular paint, but if you need very fine fineness (Hegman 6+), you need a bead mill. A bead mill uses tiny glass or zirconia beads to grind the pigment particles down to sub-micron sizes. It's the only way to get truly premium fineness.
4. Tip #4: Use Better Pigment
Not all pigments are created equal. Cheaper pigments have larger particle sizes and are harder to disperse. If you're struggling to get good fineness, try switching to a better quality pigment. The extra cost will pay for itself in better paint quality and faster dispersion time.
5. Tip #5: Check Your Equipment
If your disperser is too small or underpowered, it won't create enough shear to break down the pigment agglomerates. Make sure your disperser has enough power (at least 15kW for a 500L batch) and that the disc is the right size and at the right height (about 1/3 of the liquid depth).
Conclusion
Getting good paint fineness isn't rocket science. Use enough dispersant, mix long enough, and make sure your equipment is up to the job. If you need premium fineness, invest in a bead mill. These five tips will solve 99% of your fineness problems.
Not sure if your equipment is powerful enough? Contact our engineers — we'll help you figure out the right setup for your production.
Need Better Dispersion Equipment?
We manufacture high-speed dispersers and bead mills for perfect fineness.
Get a Quote →