We are open Monday to Thursday 9am to 5pm. On Fridays we are open 9am to 3pm.

Yes, we have multiple distributors! Your nearest distributor can be found on our website under “Find a distributor“.

As this is a new address try using ST4 2LT to find us (please don’t use the HGV entrance). It is easier to use google maps and search Valentine Clays which will bring you to the correct entrance.

It is the your responsibility to have your clay tested for food safety as production techniques and conditions may vary, we recommend speaking with our technician for advise on this. Please email us at technical@valentineclays.co.uk.

If you are experiencing any difficulties with accessing your account please email us on sales@valentineclays.co.uk and a member of our team will be able to assist you.

Your carriage cost will be calculated at the checkout based upon the weight of your order, and your location. This cost will also include a pallet charge if over 75kg in weight. Find out more about delivery here

Yes! If you would prefer to arrange your own transport, please let us know at the time of ordering. If you are arranging for a courier to collect your order, please inform us so that we can ensure the goods are packaged correctly for transport.

1. Exposure to Air:
   If your clay was not stored properly, it may have dried out from air exposure particularly if the atmosphere has low humidity.
   
   
2. High Water Absorption:
   Porous clay can lose moisture quickly if stored in an area with low humidity.
   
   
3. Storage Issues:
   Storing clay in warm or dry environments (e.g., near a radiator) can cause it to harden.
   
   
4. Clay Aging:
   Over time, some clays naturally dry out and become less workable.

Yes hard clay can be fixed!

1. Rehydrate the Clay

• Damp Towels
• Soaking in Water

2. Slaking Method (for Very Hard Clay)

• Break the clay into small pieces.
• Submerge the pieces in water completely until they dissolve into a slurry.
• Spread the slurry on a plaster bat or fabric surface to let excess water evaporate.
• Once it reaches the desired consistency, wedge it to prepare it for use.

3. Using a Clay Mixer (If Available)

• If you have access to a pug mill or clay mixer, you can reprocess the clay, adding water gradually until it softens. Otherwise, you will need to wedge the clay by hand and gradually add small amounts of water using a spray bottle for better control.
  

Keeping your clay in top-notch condition isn’t just about saving your projects; it’s also about saving some cash!

You can prevent clay getting hard, following these storage tips.

1. Store Properly:
   Keep your clay in an airtight bag and seal it well after every use.
   
   
2. Add Moisture Regularly:
   Place a damp sponge or cloth inside the bag with your clay if you plan to store it long-term.
   
   
3. Rotate Stock:
   Use older clay first to ensure it doesn’t dry out over time.

Read our blog on how to store clay effectively throughout the year here

1. Excess Water Added:
   Overhydration during reclaiming or storage can make clay overly soft.
   
   
2. Improper Storage:
   Storing clay in a very damp or humid environment can increase its water content if not properly sealed from the atmosphere.
   
3. Improper Handling:
   When handling a bag of clay, care should be taken not to drop or bang the bag against hard surfaces, as this can cause the clay particles to become excessively mobile and thus create a product which is too soft to work with.
   
   
4. Clay Composition:
   Some clays naturally have a softer, stickier texture depending on their formulation, for example those containing a high proportion of ball clay.
   
   
5. Temperature Effects:
   During storage, large changes in the temperature can cause the clay to sweat inside the plastic bag, creating a film of water on the surface of the clay which creates a wet sticky product.

Yes you can!

1. Dry the Clay Out

Spread the Clay on a Surface:
Place the clay on a plaster bat, wooden board, or any absorbent surface to draw out excess moisture. Flip the clay occasionally for even drying.

Use a Fabric Surface:
Wrap the clay in a cotton or canvas cloth and let it sit to wick away moisture.

Avoid Over-Drying:
Check the clay periodically to prevent it from getting too hard.

2. Wedge the Clay

Thoroughly wedge the clay to distribute any remaining moisture evenly.
This can improve the workability of slightly soft clay.

3. Blend with Firmer Clay

Combine the soft clay with harder clay of the same type.
Wedge or use a clay mixer (if available) to create a consistent texture.

Preventing Overly Soft Clay

1. Store in Airtight Containers:
   Prevent clay from absorbing excess moisture during storage.
   
   
2. Control Humidity:
   Keep clay in a cool, dry area to avoid additional moisture absorption.
   
   
3. Avoid Adding Too Much Water During Reclaiming:
   Use just enough water to soften the clay without making it sticky.
   
4. Don’t throw the clay around:
   Unless intentionally wedging the clay, handle the bag with care as force applied directly to the bag will soften the contents and may make the clay unusable at least for a while.

Read our blog about how to store clay effectively throughout the year here

Frost proofing your ceramics is crucial if they are likely to be exposed to freezing conditions.   Water absorbed by the clay body can freeze, expand, and cause cracks, especially if these freeze-thaw cycles are repeated over time. 

Here’s how to make your ceramics more frost-resistant: 

1. Use the Right Clay Body

Choose a Low-Porosity Clay:
Use stoneware or porcelain clay, as they are less porous and more frost-resistant than earthenware.

Fire to Maturity:
Ensure your clay is fired to its proper vitrification temperature (usually cone 5-10 for stoneware or porcelain). A fully vitrified clay body absorbs less water, making it more frost-proof.

2. Test for Water Absorption 
After firing to peak temperature, weigh around 100 grams of the fired clay as accurately as possible.  Then boil in water for 30 minutes followed by immersion in cold water.  After 24 hours in cold water, remove excess surface water with a moist cloth and reweigh the fired piece of clay. This is called the soak weight.

The percentage water absorption is calculated as:

Soak Weight (above)
Minus Dry Weight
x 100
Divided by Dry Weight 

Aim for a water absorption rate below 3% and for best frost resistance, less than 1%. 

3. Apply Effective Glazes

• Use Waterproof Glazes:
  Apply a durable glaze that seals the ceramic surface.
  
  
• Fully Glaze Exposed Surfaces:
  Cover both the inside and outside of the piece with glaze to minimize water absorption.
  
  
• Leave Drainage Holes:
  For items like planters, ensure there's a hole for water to drain so it doesn’t pool and freeze.

4. Apply a water proofing film 

• Clear brick sealant:
  In the event the piece of work is unglazed and cannot be fired to a sufficiently low water absorption, then a clear brick sealant such as FEBSILICON can be applied to prevent water penetration.  Apply several coats to any unglazed surface areas to create an impermeable barrier. 

Freezing clay is a common issue in colder climates, but don't worry—your clay can likely be salvaged!

Here's what to do:

1. Thaw the Clay Slowly
   Move the frozen clay to a warmer area, and allow the temperature to increase gradually over a few days until it reaches room-temperature.  This will allow the clay to thaw gradually and help prevent the loss of water from the surface of clay which can occur if the temperature is raised too rapidly. 
   
   Avoid applying direct heat (like a radiator or heater) as it can dry out the clay unevenly. 
   
   
2. Inspect the Clay
   Once thawed, check the texture. Freezing may cause the clay's structure to change, making it grainy or uneven.
   
   
3. Reclaim the Clay
   If the clay's consistency has been affected:

• Slice and Wedge:
  Slice the clay into manageable pieces and wedge it thoroughly. This helps re-distribute moisture and eliminate air pockets caused by freezing.
  
  
• Add Water if Dry:
  If the clay feels stiff, add a little water during the wedging process. Use a spray bottle for better control.
  
  
• Rehydrate with Slaking: If the clay is unusable, you can fully reclaim it by breaking it into smaller pieces, letting it soak in water until it slakes down, then re-mixing it.
  

Prevent Future Freezing
Store clay in a frost-free location, such as a basement or insulated area. Wrap the clay tightly in plastic and keep it in an airtight container to minimise temperature fluctuations.

If stored in areas without heating, ensure the clay is not in direct contact with the ground by placing on wood and insulate well with thick blankets or other similar materials.  

Read more on storing clay effectively throughout the year here

Why consider mixing clays?
People mix clays for numerous reasons:

1. To Modify Properties:
   Combine clays to adjust texture, plasticity, colour, or firing temperature.
   
   
2. To Use Up Scraps:
   Reclaim leftover clays by combining them, as long as they're compatible.
   
   
3. Create Unique Effects
   Layer or swirl different clays for decorative techniques.

Important Considerations

1. Firing Temperature (Maturity)
Ensure the clays have similar firing ranges. Mixing a low-fire clay (e.g., earthenware) with a high-fire clay (e.g., stoneware) can cause issues like warping or unusual melting behaviour.

2. Shrinkage Rates
Clays with different shrinkage rates during drying and firing can lead to cracks or separation. Test a small batch first if you’re unsure of the shrinkage compatibility.

3. Plasticity
Some clays have more plasticity than others. Mixing a very plastic clay with a less plastic one can seriously diminish workability. Wedging thoroughly helps blend the properties evenly. 

4. Mineral Content
Clays with different mineral compositions may react differently in the kiln, affecting colour, glaze adhesion, or even causing unexpected results such as sudden rapid melting during firing due to a phenomenon known as a eutectic.  A eutectic can be created where the ratio of some ingredients combine to shorten the firing range of a clay by 50C or more.   

Caution needs to be exercised and testing is crucial to understand the risks involved. 

5. Consistency
Mix clays of similar moisture levels to avoid difficulty during wedging. If one is much wetter, let it dry out slightly or rehydrate the drier one before mixing.

How to Mix Clays -

1. Prepare Both Clays:
   Ensure both clays are at similar moisture levels.
   
   
2. Cut and Layer:
   Slice each clay into thin slabs and layer them together.
   
   
3. Wedge Thoroughly:
   Wedge the clays together until the mixture is uniform.
   
   
4. Test Fire: Make a small test piece and fire it to your usual temperature to ensure compatibility. Then repeat the firing at 10 - 20 degrees above your normal temperature.  This will determine if you have sufficient firing latitude for unexpected melting behaviour.

Tips for Success -

Start Small:
Test a small batch before committing to a large amount.

Document Ratios:
If the result is successful, note the proportions for future use.

Be Creative:
Use intentional mixing techniques (e.g., marbling or blending colours) to create visually interesting results.

If you’re mixing for a specific project or have concerns about compatibility, please get in touch!

Our products are packaged in a variety of recycled, compostable, biodegrable packaging. Some of our range is still packaged in single use plastic.

Find out about our packaging here

We are committed to sustainability and aim to continue to reduce our carbon footprint by investing in better and more sustainable packaging materials and methods.

Testing clay is the most important part of ceramics production.
Clay is a raw material and even with strict production procedures materials can fluctuate.
Testing identifies issues early into a project to avoid waste of time and money.

1. Identify Suitability for Your Project

• Testing helps you determine if the clay’s properties—such as plasticity, strength, and texture—align with your intended use (e.g., functional ware, sculpture, or decoration).

2. Check Firing Compatibility

• Ensures the clay can handle your chosen firing temperature without issues like slumping, blistering, bloating or under-firing.
• Verifies compatibility with glazes to avoid defects like crazing or peeling.

3. Avoid Structural Failures

• Identifies problems like cracking, warping, or shrinkage during drying and firing.
• Helps you assess whether the clay can handle specific design requirements, such as thin walls or large-scale forms.

4. Assess Water Absorption

• Ensures the clay is sufficiently vitrified for its intended use, especially for functional or outdoor pieces that need to be waterproof or frostproof.

5. Achieve Desired Aesthetic Results

• Allows you to test how the clay interacts with glazes, slips, and decoration techniques.
• Helps you evaluate the fired colour and surface finish.

6. Save Time and Resources

• Catching issues early through testing prevents wasted materials, time, and effort on pieces that might fail later in the process.

7. Ensure Consistency

• Regular testing of clay batches ensures consistent performance, especially if you’re working with natural or reclaimed clay that may vary in composition.

Testing is a vital step to ensure your clay performs as expected, minimising risks and maximising the quality of your finished work. 

Exploring ceramics reveals a range of clay types, each with unique qualities. Stoneware clay and Earthenware clay are prominent options, each with specific compositions and applications.

Stoneware Clay is renowned for its endurance and adaptability, occupying a revered spot in the ceramics industry.

Earthenware Clay embodies a more primal essence and malleable nature and offers a lower firing temperature.

Read our in depth blog that highlights the difference between Stoneware and Earthenware

Cracking is a common issue in ceramics that can occur at various stages of the process. Understanding the causes and how to prevent them will help you produce stronger, more durable pieces.

1. Uneven Drying

Cause: Clay dries unevenly when some areas lose moisture faster than others, creating stress and cracks.

Fix: Dry your pieces slowly and evenly, especially larger or thicker ones. Cover with plastic and let the moisture equalise gradually. Turn pieces periodically to allow even airflow.

2. Poor Design

Cause: Sharp corners, inconsistent wall thickness, or weak joins can create stress points.

Fix: Ensure walls and bases have consistent thickness. Round sharp edges and avoid abrupt transitions in the design. Properly join pieces by scoring, slipping, and compressing well.

3. Inadequate Wedging

Cause: Air bubbles trapped in poorly wedged clay can expand during drying or firing, leading to cracks.

Fix: Wedge clay thoroughly to remove air pockets and create a uniform consistency.

4. Rapid Temperature Changes

Cause: Sudden changes in temperature during firing or cooling can cause thermal shock, leading to cracking.

Fix: Use a slow and controlled firing schedule, particularly during critical stages like bisque firing and cooling.
Allow the kiln to cool completely before removing pieces.

5. Overly Wet or Dry Clay During Assembly

Cause: Joining pieces at different moisture levels can lead to cracking as the clay shrinks unevenly.

Fix: Assemble pieces at similar moisture levels (leather-hard is ideal). Score and slip properly to ensure a strong bond.

6. Incompatible Clay Body

Cause: Some clay bodies are more prone to cracking due to their composition or firing requirements.

Fix: Choose a clay body suitable for your project (e.g., grogged clay for large or sculptural pieces). Test new clay bodies before using them for significant projects.

7. Excessive Drying Shrinkage

Cause: Clay with a high shrinkage rate may crack as it dries and shrinks unevenly.

Fix: Use a clay body with lower shrinkage if cracking is a persistent issue. Dry pieces slowly and evenly to reduce stress.

8. Overfiring

Cause: Firing at too high a temperature can weaken the clay and cause cracking.

Fix: Verify the correct firing temperature for your clay and glaze. Use cones to ensure accurate firing in your kiln.

9. Improper Handling After Firing

Cause: Mishandling finished ceramics, especially large or thin pieces, can create cracks.

Fix: Allow pieces to cool completely in the kiln before handling. Support delicate or large pieces properly when moving them.

10. Cracks in Glaze

Cause:
Crazing or cracking in the glaze can result from an incompatible glaze and clay body.

Fix:
Test glaze fit with your clay body to ensure proper thermal expansion compatibility.

By identifying when and where the cracking occurs (during drying, firing, or post-firing), you can pinpoint the cause and take appropriate steps to prevent it. Testing and adjusting your process can lead to stronger, more reliable ceramic creations.

Glaze bubbling, also known as "blistering," occurs when trapped gases in the glaze or clay body expand during firing, creating bubbles that burst and leave crater-like marks.

Here are common reasons for bubbling and how to fix it:

1. Insufficient Firing Time or Temperature

• Cause: Gases from the clay or glaze don't have enough time to escape before the glaze cools and solidifies.
• Fix: Extend the firing time or increase the hold at peak temperature to allow more time for the glaze to mature and gases to escape.

2. Poor Glaze Application

• Cause: Glaze applied too thickly traps more moisture and air, leading to bubbling during firing.
• Fix: Apply thinner, even layers of glaze. Dip, brush, or spray evenly, and let each layer dry thoroughly before applying the next.

3. Contamination

• Cause: Dust, dirt, or oils on the bisqueware can interfere with the glaze, creating bubbles.
• Fix: Wipe your bisqueware with a damp sponge before glazing to remove any surface contaminants.

4. Bisque Firing Issues

• Cause: If the bisque firing is too low or rushed, organic materials and moisture remain in the clay, releasing gases during the glaze firing.
• Fix: Bisque fire to a higher temperature (e.g., cone 04 instead of cone 06) to burn out impurities more thoroughly.

5. Clay Body Issues

• Cause: Some clay bodies contain organic materials, grog, or impurities that release gases during firing.
• Fix: Test your clay for compatibility with the glaze and consider switching to a less gas-prone clay body if issues persist.

6. Incompatible Glaze Formula

• Cause: Certain glaze recipes are more prone to bubbling due to ingredients that release gases at high temperatures (e.g., carbonates or organic materials).
• Fix: Adjust the glaze recipe to reduce volatile ingredients, or reformulate with a flux that melts at a lower temperature.

7. Rapid Cooling

• Cause: Cooling the kiln too quickly can cause bubbles to solidify before they pop and smooth out.
• Fix: Slow down the cooling cycle, especially in the early stages after peak temperature.

8. Firing Schedule

• Cause: Firing too fast or not allowing proper soaking at certain temperature ranges can trap gases.
• Fix: Use a controlled firing schedule, with slower ramps and soaks, particularly between 500°C–900°C (932°F–1652°F) to burn out carbonates and organics.

9. Re-glazing and Refiring

• Solution: If the bubbling is minor, you can sand the surface, clean it, and apply a thin layer of glaze before refiring. Ensure the firing schedule is adjusted to address the original issue.

By identifying the specific cause of the bubbling, you can take targeted steps to resolve it. If you’re unsure, test changes on small pieces before applying them to a full batch.