How to Use Thinners and Degreasers the Right Way in Auto Body Work

In automotive refinishing, a flawless finish doesn’t start with the paint, it starts with how well you prepare the surface. Two products often overlooked, but absolutely essential, are thinners and degreasers.

Whether you’re a beginner just learning spray techniques or a professional running a busy shop, mastering these products can save you time, money, and rework.

In this guide, you’ll learn:

• The difference between thinners and degreasers

• How to choose the right one for the job

• Pro tips and mistakes to avoid for a professional finish

Thinners vs. Degreasers: What’s the Difference?

Thinners

Thinners adjust the viscosity of your paints, primers, or clearcoats. Their main jobs are to:

• Improve sprayability and leveling

• Control drying time (faster or slower, depending on climate and job size)

• Reduce issues like orange peel or uneven flow

👉 Think of thinners as “flow control” they help your coating apply smoothly and evenly.

Degreasers

Degreasers clean the surface before paint ever touches it. Their role is to:

• Remove oils, waxes, silicone, and fingerprints

• Ensure proper adhesion of primer and topcoat

• Prevent paint defects like fish eyes or peeling

👉 Think of degreasers as “insurance” they ensure nothing comes between your paint and the panel.

KMK Degreasers: Start With a Clean Surface

KMK 6005 Normal Degreaser – 5L

• For general use in body shops

• Removes surface oils, dust, and light contaminants

• Quick-drying formula

💡 Best for: Beginners or quick prep before primer and filler. Easy to apply with a cloth using the two-cloth method.

 KMK 6105 Slow Degreaser – 5L

• Slower evaporation for deep cleaning

• Extended wipe time to release stubborn dirt

• Excellent in hot climates or on complex surfaces

💡 Best for: Professionals dealing with heavy contamination or who need more control.

 KMK Thinners: Get the Flow Just Right

 KMK 5105 Slow Thinner – 5L

• Slows drying for better leveling

• Ideal in warm climates where paint dries too fast

• Reduces overspray texture

💡 Use with: Clearcoats like KMK 2404 or primers like KMK 36038 for a mirror-like finish.

KMK 5005U Normal Thinner – 5L

• Balanced drying time for most applications

• Works well in standard shop temperatures

• Versatile for basecoats, primers, and clearcoats

💡 Best for: Everyday jobs when you need a reliable all-around thinner.

 Pro Tips for Perfect Application

✅ Degreasers:

• Always use the two-cloth method (wipe on with one, immediately wipe off with another).

• Degrease before sanding and after sanding to remove dust and hand oils.

• Never let degreaser dry on the surface.

✅ Thinners:

• Follow the TDS (Technical Data Sheet) for mixing ratios.

• Select thinner speed based on booth temperature and job size.

• Don’t over-thin, it weakens coverage and causes orange peel or runs.
  
  

Final Thoughts

A flawless paint job begins long before you pick up the spray gun. Using the right thinner and degreaser means smoother application, stronger adhesion, and fewer costly re-dos.

At KMK Refinish USA, we provide professional-grade thinners and degreasers designed for real body shop conditions. Whether it’s a quick touch-up or a full respray, the right prep products will set you up for success.

✅ Prep like a pro.
👉 Explore our complete range of KMK Thinners & Degreasers,  because great results come from clean, controlled beginnings.