For serious contamination. Polish after use.

Claying is one of the most satisfying things you can do for your car — you can actually feel and hear the difference as you work. It's like exfoliating your paint. Paint is porous, just like your skin, and over time contaminants like industrial fallout, brake dust, tree sap and road grime embed themselves into the pores. A clay bar is a sticky, pliable substance that grabs those contaminants and pulls them out — leaving paint that feels genuinely smooth, looks better, and is properly prepared for whatever you want to apply next.

The Rockcar Heavy Clay is the most aggressive grade in the range. It removes the most contamination and works the fastest — but it carries a higher marring risk than the light or medium bars. This is not the clay to reach for if you're new to detailing or working on paint you're not planning to polish. It's the right choice when you're doing a full professional decontamination and correction job, and polishing is already on the plan. The marring it may leave behind will come out in the polish — and the paint underneath will be as clean and bare as it gets.

Be honest with yourself about which clay you need. For most cars in most conditions, the medium bar is the better choice. Reach for the heavy bar when you're dealing with seriously contaminated paint — industrial fallout, heavy tar, overspray, or a car that hasn't been properly clayed in years — and when you have the skills and equipment to follow up with a polish.

Why clay before coating or waxing? If you're planning to apply a ceramic coating, wax, glaze or sealant, claying first isn't optional — it's essential. Coatings bond to bare paint. Contaminated paint means your coating is bonding to the contamination, not the paint itself, which means it won't last or perform as well. Clay first, coat second. Always.

A few important tips:

• Always use plenty of clay lube — we recommend the Autostolz Quick Detailer & Clay Lube as it's formulated specifically to maximise lubrication without breaking down the clay. Soapy water can work in a pinch but most car wash soaps contain surfactants that break clay down faster — what you save on lube you spend replacing clay sooner
• Work in the shade on cool paint
• Tear off around a third of the bar at a time and keep the rest sealed — if you drop a piece on the ground, throw it away immediately. It will have picked up grit and will scratch your paint. No exceptions
• Fold the clay over on itself regularly as you work to bring a fresh surface to the front
• Always polish after using heavy clay — do not leave marring unaddressed
• Once you're done, always apply a layer of protection — wax, sealant or ceramic coating

Not sure which clay to choose?

• 🟢 Light — safest, easiest, best for beginners and lightly contaminated paint
• ⬜ Medium — faster, removes more, best for most people and most situations
• 🔴 Heavy (this one) — maximum contamination removal, for professional and semi-professional use, higher marring risk, polish after use
• 100g bar
• 70×55×19mm
• Heavy grade — maximum contamination removal, higher marring risk
• Colour: Red
• Made in Malaysia
• Do not use on matte, satin or wrapped surfaces
• Always follow with a polish

A note on clay bar weights: not all 100g clay bars are actually 100g. We've stopped stocking certain brands after discovering their bars were significantly underweight — you were paying for 100g and receiving considerably less. The Rockcar clay bars are a genuine 100g. We weigh them.