Wash and Decontamination
How to Clay Bar a Car
Claying is simple and the failure modes are specific. Here is the sequence, the test that tells you whether the car needs it, and what goes wrong when people rush it.
By Sawyer V. · Last verified 2026-09-08
We have not tested any of this. Everything below is compiled from published manufacturer specifications, and the arithmetic is printed so you can check it. This page carries affiliate links: if you buy through one we earn a commission at no extra cost to you, and it does not change the order of the picks. Full disclosure.
| # | Pick | Best for | Score | Price |
|---|---|---|---|---|
| 1 | ULTRA Clay Mitt The Rag Company | Doing a whole car without losing an afternoon | 4.3/10 | Check price on Amazon |
| 2 | Stjarnagloss Glir Clay Lubricant Stjarnagloss | The cheap bottle that stops you marring the paint | 6.7/10 | Check price on Amazon |
| 3 | Koch-Chemie Clay Bar Koch-Chemie | The only clay here that publishes its grade | 4.6/10 | Check price on Amazon |
| 4 | Adam's Iron Remover Adam's Polishes | The default, and the one with the clearest safety wording | 7.0/10 | Check price on Amazon |
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. Why we do it that way.
First, find out whether you need to
Wash and dry the car. Put your hand inside a thin plastic sandwich bag and run it lightly across a horizontal panel — the roof or the hood, where fallout lands hardest. The bag amplifies texture your fingers cannot feel. If it drags and feels like fine sandpaper, the paint has bonded contamination. If it glides like glass, it does not, and claying it will remove nothing while adding marring risk.
This test is the whole diagnostic and it takes ten seconds. Most cars need claying once or twice a year; a garaged weekend car might go two years between passes.
The sequence
- 1Wash the car properly first. Claying a dirty car drags loose grit under the medium. Use the two-bucket method and dry it.
- 2Decontaminate chemically before mechanically. Spray an iron remover, let the color change develop, rinse thoroughly. This dissolves ferrous particles so the clay has less to shear off, which means less marring and a medium that lasts longer.
- 3Work in shade, on a cool panel. Lubricant drying mid-pass is the mechanism behind most claying marring.
- 4Prepare the medium. Knead a bar flat into a palm-sized disc. Rinse a mitt or towel and check the face for embedded grit.
- 5Lubricate until the panel is visibly wet. Not damp. A 500ml bottle of dedicated lubricant costs $7.50 and you will use most of it on a car.
- 6Glide in straight overlapping lines. No circles, no pressure. The clay should slide; if it grabs, add more lubricant.
- 7Inspect after every section. Refold a bar to a clean face when it discolors. Rinse a mitt. Discard anything that has been dropped.
- 8Wipe dry and protect the same day. The paint now has nothing on it.
The three mistakes that cost you paint
Using water or shampoo instead of lubricant
This is the big one. Dedicated lubricant carries removed contamination away from the clay face; water does not, so the debris stays trapped between the medium and the paint and gets dragged. Every marring complaint about claying traces back here more often than to any other cause.
Pressing
Clay works by shearing off what protrudes, and pressing does not make it shear harder — it forces the trapped debris deeper into the medium and closer to the paint. If a spot is not coming clean, add lubricant and make more passes rather than leaning on it.
Continuing with a dropped or loaded bar
A bar that has hit the floor has picked up whatever was on it. A bar whose face has gone gray with contamination is a bar carrying that contamination. Refold or replace, and accept that a bar is a consumable.
What claying does not do
It does not remove swirl marks, scratches or oxidation. Clay removes what sits above the clear coat; defects are in the clear coat, and removing those means polishing. What paint correction is covers the difference, and it is the step that comes after this one if the paint needs it.
It also does not make paint shinier by itself, though it will feel like it did. What changes is that the surface is now smooth, so light reflects evenly and whatever you apply next bonds to clear coat rather than to contamination.
Every pick, with the working
Each entry lists the specifications the maker publishes, the axis scores those specifications produce, and what you give up. Rows that read “Not published” are not omissions on our side: they are figures the maker will not commit to in writing, and they cost the product points on the transparency axis.
Our pickDoing a whole car without losing an afternoon
ULTRA Clay Mitt
The Rag Company
$35.10 for an 8.7 by 5.7 inch mitt, which is the only published dimension in this clay group. A mitt covers a panel in a fraction of the passes a bar needs, and it survives the floor.
- Dimensions
- 8.7 in x 5.7 in
- Format
- Mitt
- Stated position
- Use before waxing, buffing and polishing
- Grade
- Not published
- Stated lifespan
- Not published
What it does well
- Dimensions published, so you know the coverage per pass before buying
- Survives being dropped, unlike a bar
- Explicitly positioned as an evolution of the bar rather than a different job
Who it is not for
- $35.10 is over four times the price of a clay bar
- No grade published
- A mitt is less precise than a bar around badges and edges
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- No single published number decides capability in this category, so the axis is dropped rather than invented.
- Cost per ouncedropped
- Either the list price or the container size is unpublished, so the division cannot be done and the axis is dropped.
- Price against the ceiling2.2/10, weight 14%
- A listed $35.10 against the $45 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- The Rag Company publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency6.0/10, weight 18%
- 3 of the 5 specifications we went looking for are published by The Rag Company. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $35.10 per The Rag Company, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from The Rag Company's ULTRA Clay Mitt listing, compiled September 8, 2026.
2The cheap bottle that stops you marring the paint
Stjarnagloss Glir Clay Lubricant
Stjarnagloss
500ml at $7.50, and the argument for it is made on its own listing: water is a poor lubricant and shampoo is not much better, because neither carries the contamination away from the clay face. Cheapest insurance in this hub.
- Size
- 500ml
- Stated use
- Spray onto a wet panel before claying
- pH
- Not published
- Dilution
- Not published
- Coverage
- Not published
What it does well
- $7.50 for 500ml, which is less than the cost of one panel of marring
- The listing explains why water and shampoo are insufficient, which is the actual point
- Works with bars, mitts, towels and blocks alike
Who it is not for
- No dilution published; it is ready to use, but that is not stated as a spec
- 500ml is not much for a full-car decontamination
- No pH figure published
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- No single published number decides capability in this category, so the axis is dropped rather than invented.
- Cost per ounce9.6/10, weight 16%
- $7.50 for 16.91 oz works out at $0.44 an ounce, scored against a band of $0.40 (good) to $1.50 (expensive) for a clay lubricant.
- Price against the ceiling7.0/10, weight 14%
- A listed $7.50 against the $25 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- Stjarnagloss publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency4.0/10, weight 18%
- 2 of the 5 specifications we went looking for are published by Stjarnagloss. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $7.50 per The Rag Company, 500ml, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from The Rag Company's Glir Clay Lubricant listing, compiled September 8, 2026.
3The only clay here that publishes its grade
Koch-Chemie Clay Bar
Koch-Chemie
$39.59 for 200 grams, in blue (mild) or red (a more aggressive grade), and it is the only clay in this ledger that tells you which is which before you buy. Weight and grade published on one page is the whole reason it costs more than double the alternatives.
- Weight
- 200 grams
- Grades
- Blue = mild cleaning clay; Red = stronger cleaning clay
- Stated contaminants
- Tree resin, insects, rust bloom, brake dust, overspray, tar, limescale
- Stated surfaces
- Paintwork and glass
- Lubricant included
- Not published
What it does well
- Grade published: blue is stated mild, red is the stronger cleaning clay
- 200 grams published, which is roughly twice a standard consumer bar
- Named for tree resin, rust bloom, brake dust, tar and overspray specifically
Who it is not for
- $39.59 is more than double the cheap bars
- No lubricant included at that price
- Professional sizing is more clay than a once-a-year decontamination needs
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- No single published number decides capability in this category, so the axis is dropped rather than invented.
- Cost per ounce3.7/10, weight 16%
- $39.59 for 7.05 oz works out at $5.62 an ounce, scored against a band of $1.50 (good) to $8.00 (expensive) for a clay.
- Price against the ceiling1.2/10, weight 14%
- A listed $39.59 against the $45 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- Koch-Chemie publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency8.0/10, weight 18%
- 4 of the 5 specifications we went looking for are published by Koch-Chemie. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $39.59 per The Rag Company, 200g, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from The Rag Company's Koch-Chemie Clay Bar listing, compiled September 8, 2026.
4The default, and the one with the clearest safety wording
Adam's Iron Remover
Adam's Polishes
16oz at $16.99, pH neutral, acid-free, ready to use with no dilution, and stated safe on clear coat and single-stage paint. Four safety-relevant claims on one page is more than anything else in this class publishes.
- Sizes
- 16oz / gallon / 5 gallon
- pH
- Stated pH neutral, acid-free
- Dilution
- Ready to use, no dilution
- Stated paint safety
- Clear coat and single-stage paint
- Color change
- Turns red as it reacts with ferrous contamination
- Dwell time
- Not published
- Coverage
- Not published
What it does well
- pH neutral and acid-free, both stated plainly
- Explicitly stated safe on single-stage paint, which most iron removers do not address at all
- Ready to use, so there is no dilution to get wrong
- Gallon and five-gallon sizes for anyone decontaminating regularly
Who it is not for
- No pH figure published, only the word neutral
- No dwell time published, and dwell is what decides whether it works or dries on
- No coverage figure published
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- No single published number decides capability in this category, so the axis is dropped rather than invented.
- Cost per ounce8.0/10, weight 16%
- $16.99 for 16 oz works out at $1.06 an ounce, scored against a band of $0.70 (good) to $2.50 (expensive) for a iron remover.
- Price against the ceiling5.8/10, weight 14%
- A listed $16.99 against the $40 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- Adam's Polishes publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency7.1/10, weight 18%
- 5 of the 7 specifications we went looking for are published by Adam's Polishes. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $16.99 per Adam's Polishes' own store, 16oz, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from Adam's Iron Remover product page, compiled September 8, 2026.
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. Why we do it that way.
Questions people actually ask
+How do I know if my car needs claying?
+Can I clay a car in the sun?
+How long does claying a car take?
+Do I need to polish after claying?
+What do I do if the clay grabs and stops sliding?
Where these figures came from
- The Rag Company, ULTRA Clay Bar listing — retrieved 2026-09-08
- The Rag Company, Glir Clay Lubricant listing — retrieved 2026-09-08
- Adam's Polishes, Iron Remover product page — retrieved 2026-09-08
Every figure on this page is a published manufacturer or authorized-retailer claim, not a measurement we made. How we research explains exactly what we did and did not do.