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Selecting Clays
PREPARED CLAY BODIES - Descriptions
Powdered Clay Bodies
Air Hardening Clay etc.
Firebrick Grogs
Casting Slips
Basic Materials
Leading Suppliers
We have been renowned as leading suppliers of clay for over fifty years, most of these clays being based upon the unique deposits taken from our clay mines at Brownhills, South Staffordshire. In the last twenty years or so we have however substantially increased our manufacturing capabilities to include the manufacture of specialised grogs, a comprehensive range of glazes and a wide range of top quality kilns of both electric and gas fire types. Whilst our product range is now very extensive we would however emphasise that our marketing strategy is based upon flexibility and we are able to produce clays, glazes and kilns to customers specification. If you therefore require a product not included in this catalogue or you require any amendment or modification, do please let us know.

Our range is for potters, sculptors, tilemakers and ceramists in craft, education and industry. Generally we have sought in its pages to bring together a combination of our own manufactured products with a selection of other brand names, many from prestigious international suppliers for whom we are U.K. Distributors. In addition we have sought to provide much useful technical data so as to enable not only easier selection of the product most suitable for a particular requirement but also to provide important health and safety information.

We endeavour to cater for all degrees of skill: for the expert we offer a wide range of clays, glazes, colours etc,. Suitable for use in advanced techniques and capable of giving superb results. On the other hand, we appreciate the difficulties of the less skilled and hence provide literature and technical advice to assist in the choice of materials, equipment and making methods.

We also extend a cordial invitation to visit us at our Etruria Showrooms. You would always be most welcome and could collect any requirements ‘on the spot’ thus avoiding carriage charges.
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Selecting Clays
All our clay bodies are in plastic form, packed in 12.5 or 25kg packs, and ready for use. When stored in a cool but frost-free situation, free from draughts and direct sunlight, the clay packs will retain their condition almost indefinitely.

For general use we particularly recommend 150-1102 and 151-1124 bodies, both of which are slightly grogged. If a smooth clay is preferred then we suggest clays 159-1131, 159-1135, or 159-1137 (red), 151-1120 (buff) or 158-1141 and 158-4130 (white). For more specialised needs the chart and data given on pages 3-4, 6-7 and 66 will assist.

Clays of wide firing range: Some clays have very wide firing ranges, enabling them to be used for earthenware (1100-1150oC), middle temp.(1180-1220oC) Or stoneware (1220-1300oC).

These are: Buff firing: 150-1102, 151-1120, 151-1124, 157-1150 Red firing: 159-1131, 159-3140, 159-1134 White firing: 158-1141, 158-2144, 158-4130

Glaze Suitability/Firing Temperatures

We recommend biscuit firing at 1000-1060oC then following with a glaze firing to a higher temperature which matures both the clay and the glaze at the same time.

Each clay body and each glaze is catalogued with its firing range. When selecting a glaze for use with a particular clay it is important to select one with a firing range which exceeds the lower figure given for the clay. If this is not done the clay will be underfired and the glaze consequently may craze.

Alternatively one could biscuit fire the clay above the lower figure given for the clay then glaze fire to the firing range of the selected glaze. However, this method may cause difficulty with glaze pick-up when dipping (although this can be overcome: see 3442 page 20). Bone china is invariably produced this way.

Firing Rate

The optimum rate depends upon the thickness of the pots and clay type e.g. Thin cast and grogged bodies can be fired quicker than thrown and ungrogged ones. Ideally, biscuit firings would be slower than 100oC per hour up to 200oC and 100 - 200oC per hour beyond that point and ending with a short soak.

Glaze firings should be at 100-130oC per hour but at 100oC per hour maximum from 700-1100oC with high carbon ball clay or fireclay based bodies.

Maximum Firing Temperature

This is approximately indicated by the vitrification point stated for each clay on page 67 but, with stoneware, it will be lowered by reduction firing conditions and is dependent upon other factors such as firing cycle. Consequently this figure is given only as a guide for comparison purposes. If clays are fired above their vitrification point then bloating is likely. Bloating may also result from insufficient biscuit firing or too fast firing in the later stages of the glost firing. Conversely, overlong firings may give excess heat work and cause bloating.

Recipe Amendment

Recipes of heavily grogged panmilled bodies 153-1114, 153-1153 and 154-1154 were amended from May 1998 to give improved resistance to lime popping and efflorescence problems. These changes involve using new refractories instead of reclaimed firebrick as the grog source, finer processing of certain other clay constituents and the intoduction of a new version of Craft Crank, which is now listed as 153-3114 Premium Craft Crank. The fired colour may be slightly different under certain firing conditions and a fired trial is therefore recommended. Other properties, including their superb handbuilding performance, remain the same.

Manufacturing Code:

Bodies marked P are finished by our Panmilling technique. This gives excellent, reliable control of grog and water contents but is more open to occasional contamination from larger or extraneous particles arising in the ingredients or during processing. It generally produces better moisture control in grogged bodies.

S denotes sliphoused bodies. These are prepared in very large batches in slip form which is finely sieved prior to or after grog addition. The purified slip is then pumped into presses for dewatering prior to pugging. Sliphousing gives greater product uniformity and virtually guarantees freedom from contamination. Its disadvantage is that it is more difficult to control grog contents (due to settling from suspension) and moisture content. It is the best technique for smooth textured bodies. See table.
 
Some bodies are now produced by a plastic blending process, which yields bodies offering the high purity and cost effectiveness of a sliphoused product together with the ultra-tight control over grog additions previously only possible by panmilling.

Suitability Code

a Clays good for general domestic ware.

b Clays good for large domestic items also.

c Clays good for big pots, bread crocks, etc.

d Clays for large constructions and tiles needing good warp resistance.

e Clays good for general purpose use for throwing, slabbing, coiling, etc.

f  Especially good for throwing.

[back to top] Clay Selection Chart
PREPARED CLAY BODIES - Descriptions
St Thomas Clays
 
Oxidising St Thomas 150-1102
Extremely popular general purpose high earthenware and stoneware body which produces an attractive speckle under normal or slightly reducing conditions. Both tolerant and resilient it has good warp and crack resistance and is suitable for throwing and slabbing.
 
Reduction St Thomas 150-1104
An attractive toasted stoneware in oxidising conditions this body really comes into its own under reduction. The excellent handling properties make it a popular choice for domestic stoneware production.
 
White St Thomas 150-1106, 150-1506
A light grey-white colour in both oxidation and reduction combined with outstanding handling and resilience make this body the first choice for small and large work alike. The 150-1506 version is particularly free of natural speckles, and both will withstand high temperatures.
 
General Stoneware
 
Buff Stoneware 151-1117
An inexpensive fireclay based body which throws well, turns easily, and is plastic, strong and reliable making it highly suitable for domestic ware.
 
Buff School Clay 151-1120
Popular with stoneware potters as a production body for both oxidation and reduction, this dual purpose earthenware and stoneware clay is equally suited to use in schools. The fireclay, ball clay and china clay blend produces a body of smooth texture and medium shrinkage.
 
Sanded Buff 151-1124 A lightly sanded version of our Buff School Clay, this body has a much greater tolerance to making methods and is an excellent choice for school use.
 
New Lavafleck 151-1514
This new version of our highly flecked stoneware body is popular for its distinctive character. Having good throwing ability, it is now more temperature stable. Shelves need to be
well coated with refractory wash to prevent sticking during
 
Coloured Earthenware
 
New Keuper Red 159-1131
This high quality, smooth earthenware body has a low flux content to improve glaze pick-up and enabling it to be used at higher temperatures. When fired above 1200oC the body takes on a purple tone.
 
Keuper Sanded Red 159-3140
Superb body for tiles, slab work, large pieces and murals alike, this body has high resilience and good warp resistance, yet the smooth texture allows detail to be captured.
 
Grogged Red 159-1134
When used at either earthenware or stoneware, this body has good general properties, low shrinkage, and is excellent for large pots. Firing to a terracotta colour at earthenware the colour gradually changes with increasing temperature to a warm toasted brown.
 
Original Red S/E 159-1135
Carefully graded and blended red clays and fireclays give this, our original, terracotta body outstanding tolerance and physical properties. It is a good domestic earthenware body which throws and turns well.
 
Red Earthenware Terracotta 159-1137
This competitively priced body is a high quality blend of red clays and fireclay which give it a good colour and high fired strength.
 
Sanded Red 159-3730
Based on our 159-1137 body, a small addition of sand enables this body to be used for larger forms and increases warp resistance making it suitable for tile production without detracting from the pleasant terracotta colour.
 
Chocolate Black 159-2130
Especially good for sculpture this competitively priced clay fires to a chocolate black colour at earthenware temperatures and has a fine texture.
 
Smooth Throwing Stoneware
 
Flecked Stoneware 152-1109, 152-2109
Based on a blend of ball clays, this attractively flecked body is excellent for thrown domestic ware, large or small pieces. The carefully graded fleck burns through covering glazes giving a reduction fired appearance in an oxidised firing. The 152-2109 version is similar to 152-1109 but is based on higher purity sliphoused materials and is more attractively priced.
 
Stoneware Body 152-2110
This highly plastic throwing body designed for use in oxidised and reducing conditions, is suited to thrown domestic ware particularly where colour response is important.
 
Staffordshire Stoneware 152-1115
New to our catalogue, this plastic stoneware body is ideally suited to throwing, and can be used in both oxidation and reduction firings, producing a warm toasted colour. Having similar thermal properties to our white stonewares, it is also suitable for oven-to-table ware production.
 
Crank Clays
 
Ivanhoe 152-1112
This traditional formulation is superb for tiles, slab work and murals due to its excellent warp resistance and resilience. Although it has a high grog content, the smooth surface texture allows detail to be captured well in the toasted colour.
 
Craft Crank 153-1114
Regarded by many as the best crank clay available, Craft Crank is unsurpassed as a handbuilding clay. The unique blend of fireclays and ball clays produce a pleasant toasted colour in oxidation whilst the speckled orange-brown under reduction is unrivalled.
 
Premium Craft Crank 153-3114
This body offers the same properties as our original Craft Crank, but with an all ball clay base. This gives the body a smoother clay base whilst retaining the same fired colour.
 
Sculpture Crank 153-7070
A variation of our Craft Crank specially formulated for larger sculptural work. It contains slightly more coarse grog grades than Craft Crank and has a more open texture.
 
Grogged Pink 153-1127
Obtained by a carefully controlled blend of Crank and red clays, it is a general purpose handbuilding body, which fires to a pleasant pink colour at lower temperatures and gradually darkens as the temperature increases.
 
Industrial Crank 153-1153
Suitable for large sculptural work, slabbing, saggars and raku, this body is very refractory having an open texture with low shrinkage and good warp resistance.
 
Raku
 
Raku 154-1154
With superb thermal shock resistance and low shrinkage this body is not only excellent for raku work, but is also highly suited to slabbed work and is capable of firing to stoneware.
 
Coarse Raku 154-1156
With coarser grogs present, this body is designed for those producing large sculptural forms which are intended for either raku or stoneware firing. The coarse textured grogs produce a pronounced fleck when fired to stoneware.
 
Smooth Raku 154-1159 Specifically designed for those who want the strength and resistance for raku firing but in a body which can be thrown, slabbed and coiled, it contains more medium range grogs.
 
Tandoori (only available by the tonne) 154-0131 Intended for industrial applications, this body is specially designed for the production of Tandoori ovens where high strength and excellent thermal shock resistance is required. This very coarse body is not recommended for general use or for sculptural items where a high selling price is anticipated.
 
White Grogged Stoneware
 
White Crank 156-0630
White firing, this body is based on a blend of ball clay and china clay to which is added graded molochite grogs. It is excellent for the production of large forms, slabs and tiles, and can be fired to stoneware as well as used for raku.
 
T Material 156-1161
Extremely resilient and tolerant, this off-white firing body is superb for large sculpture and handbuilding use. Its low thermal expansion, low shrinkage and good warp resistance mean that it is well suited to high quality raku pieces.
 
Y Material 156-2161
White firing, this blend of ball clays and china clay with molochite grogs is the ideal choice for high quality raku pieces. Its low shrinkage and excellent warp resistance combine well to produce an outstanding sculptural body.
 
Porcelain
 
DL Porcelain 155-1147
Similar to the original David Leach body, this white, translucent porcelain is excellent for throwing.
 
HF Porcelain 155-1149
This truly excellent white-burning translucent porcelain developed by Harry Fraser combines the finest quality and value. It throws well and is consistent and reliable.
 
JB Porcelain 155-4000
Whiter firing than almost all other porcelains, this body offers good throwing properties combined with high translucency and quality at an affordable price.
 
Southern Ice Porcelain (LBSI) 155-1151
Developed in Australia by Les Blakebrough, this truly outstanding porcelain is the whitest firing and most translucent porcelain available. The unique blend of high plasticity Australasian china clays set this body in a class of its own.
 
Cool Ice Porcelain 155-1152
Developed in Australia, an outstanding low temperature translucent porcelain. The unique blend of high plasticity Australasian china clays set this body in a class of its own.
 
Bone China 155-1148
This traditional Stoke on Trent Bone China body offers users the whitest firing clay available. Like all bone china, it is best suited to slip casting or machine making, but with suitable plasticiser additions it can be converted to a flower making clay.
 
White Stoneware
 
White Stoneware 157-1145, 157-2145
This superb white stoneware body, based on carefully selected china clays and ball clays, has just sufficient added flux to maintain temperature stability yet provide exceptional ring. Excellent for small and large thrown domestic ware it stand up well even when thrown thinly. The 157-2145 version is similar to 157-1145 but is based on higher purity sliphoused materials and is more attractively priced.
 
White Special Stoneware 157-1142, 157-4230
White firing and smooth textured, this clay throws and handles well and is a very good body for domestic ware. The 157-4230 version contains a small amount of white sand which provides extra shape stability for larger domestic ware and improves the thermal shock resistance.
 
New Draycott White Stoneware 157-1143
A white firing blend of ball clay, china clay and fireclay, to which a small addition of molochite grog is made, produce a smooth body suitable for throwing and modelling both small and large domestic items for oxidised or reduction firings.
 
Modelling Clay 157-1150
Used by model makers for all types of projects, from original china figure models to film special effects, this clay is the most plastic modelling clay available.
 
White Earthenware
 
 Ivory Earthenware 158-2138
A good earthenware body for slip casting of general and domestic ware.
 
Studio White Earthenware 158-1141
This ball clay based, very plastic white firing earthenware is well suited to thrown ware. It has a good green strength and wide firing range.
 
Grogged White 158-4130
Based on the 158-1141 to which we add a small addition of graded white grog, this body has exceptional handling properties for larger items and yet can still be easily thrown.
 
Grogged White (Molochite) 158-4120
Graded molochite grogs are included in the 158-1141 base clay to give a body which has excellent workability for handbuilding, sculpture and tiles, yet still possesses a high plasticity for throwing.
 
Semi Porcelain 158-2144
A white earthenware, semi-porcelain or Parian body made to a traditional recipe which is generally suited to slip casting or machine making. Smooth in texture but of medium plasticity.
 
Paper Clay
 
Paper Clay 180-1190
Developed in conjunction with paper clay users, this body is based on a white stoneware to which carefully controlled grades of inorganic fibres and binders have been added, giving all the benefits of Paper Clay without the shelf-life problems.
 
Southern Ice Paper Clay 180-1192
All the wonderful qualities of LBSI combined with the versatility of paper clay.
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Powdered Clay Bodies
1000-2 Low temperature white e-ware
Fires white to off-white from 1020 - 1180. Good for engobing red clays, etc. 

1118-2 Buff Earthenware/Stoneware 
General purpose clay suitable for earthenware or stoneware. Firing range 1110 - 1285oC.

1135-2 Red S-E
Prepared by spray-drying our 1135 body (see page 7). Firing range 1050 - 1170oC.

1140-2 White earthenware
Firing range 1110 - 1260oC.

1145-2 White Stoneware Powder
Firing range 1210 - 1300oC.

1146-1200 Porcelain
Firing range 1170 - 1220oC. Low temperature porcelain for slipcasting. Sieve through 60 mesh sieve.

1149-2 H.F.Porcelain
Firing range 1220 - 1290oC. Should be slipped through 60 mesh or finer to give a strong, white translucent porcelain.

Raw Clays(Fireclays, Ball clays and China clays)

Specially selected for use in bodies or glazes. All are in powdered form. See page 68 for analyses. 


1273WAD Fireclay N6
Our N6 fireclay supplied in plastic form. Fires buff-grey with strong speckle at stoneware. Tremendously plastic. 

3406 Ball Clay (ESVA)

3407 Ball clay (Hyplas)
Approximately 70% SiO2.

3408 Ball clay (HVAR)

3409 Ball clay (Hymod AT)
High iron content.
 
3416 China clay
A general purpose china clay for use in bodies or glazes.

3416-3 Grolleg china clay

3416-4 Porcelain china clay

White firing china clays of world-wide reputation. Both are exceptionally white yet reasonably plastic.We Process large quantities of fireclays from our mines and additionally use a wide range of ball clays and china clays. Please let us know if there is a particular product you need which is not listed here.
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Air Hardening Clay etc.
1181-3 Hard-setting clay

An air-hardening clay supplied in small packs suitable for school use. Sets very hard - but harder still after 48 hours. Can be coloured with tempera colours, acrylics, etc. Safe to use.

1185 Newclay

Paint on to seal pieces made with Newclay to give a glossy finish.

1186 Claymate Clay Conditioner

Based on lignosulphates, this is an extremely powerful liquid for plasticising clay blends. Extremely small additions (less than 0.01%) Make a noticeable change A popular modelling clay which contains nylon fibres which much increases the strength when dry. Can be decorated with non-firing stains, acrylics, tempera colours, etc. Dry clay can be reconstituted.

1185-3 Newclay hardener

When dissolved in hot water and painted on to Newclay it further increases the strength.

1185-4 Gloss Finish

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Firebrick Grogs
Our Dry Fine Grinding installation allows us to manufacture grogs with uniquely controlled gradings and has established Potclays as leading suppliers. It also enables us to properly control the grogs used in our clay bodies. Potclay grogs are produced by crushing and grinding firebricks and other refractories under dust-extraction conditions. This removes the ultra-fine dust fraction and avoids the widely varying dust content found in other grogs.

1242 5’s (3mm) to dust

1243 8’s to 20’s (1.5mm - 0.8mm)

1245 20’s to 30’s (0.8mm - 0.4mm)

1247 20’s to dust (0.8mm - dust)

1248 30’s to dust (0.4mm - dust)

1249 30’s to 85’s (0.4mm - 0.2mm)

1250 85’s to dust (0.2mm - dust)

Molochite grogs

Calcined china clay. Fine grades (120’s & 200’s) used as clay substitute to lower shrinkage of engobes etc. The coarser grades are used as very pure white grogs.

3447-22 22’s to 60’s white grog

3447-30 30’s to 80’s white grog

3447-120 120’s to dust

3447-200 200’s to dust

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Casting Slips
Prepared to a specific gravity of 1.7 - 1.8 ( 34 - 36ozs per pint). Supplied in polythene containers, these slips are correctly deflocculated ready for use but in certain circumstances it may be desirable to thin them slightly, in which case add just a few drops of Sodium Dispex per gallon.

1200-2L Potclay White 1060 - 1140oC

1200-1 Low Temp White 1060 - 1140oC

1201 Black Earthenware 1040-1120c

1202 Red Terra Cotta 1050-1170oC

1203 White Earthenware 1100-1260oC

1204M Parian-Semi porcelain 1100-1240oC

White earthenware with extra fluxes for greater vitrification.

1205 Buff Earthenware-Stoneware 1110 - 1285oC

1206 Stoneware 1200 - 1290oC

1208M Porcelain 1220 - 1290oC

1210 Bone China 1200 - 1250oC

Casting Slips are produced by adding about 0.25% - 0.5% Of deflocculant and also water to powdered or plastic clay.Over-addition Of deflocculant causes cracking and sticking of casts on the mould. Under-addition is sometimes desirable but causes slips to thicken on standing although they will thin again on stirring (i.e.thixotropic).Sodium Silicate and Soda Ash are the usual deflocculants but we strongly recommend Sodium Dispex for topping-up addition and slip adjustment.

Low Temperature Porcelain slips A large range of low temperature porcelain slips is now available. They give excellent translucency at 1200-1220oC and will take china paint directly applied without glazing. They are manufactured in the U.S.A. By Bell Ceramics of Florida, considered by many to be the finest manufacturers of porcelain doll slips and china paints, and specially imported by us. Firing to 1220oC produces a biscuit finish of exceptionally smooth texture, perfect for porcelain dolls and ideal also for unglazed ware or conventionally where a tinted or coloured biscuit is needed.

Coloured Decorating Slips

Clay-water slips for dipping and trailing in the manner of traditional slipware. Compounded from earthenware bodies but capable of firing to stoneware. Water may be added or removed to alter the consistency. Under certain conditions dilution may be desirable to avoid flaking.

Tubeline Slip

Can be used on biscuit or clay surfaces to trail a raised outline for filling etc.
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Basic Materials
3427 Soda Feldspar (Albite)

3428 FFF Feldspar

A mixed grade of good consistency.

3429 Forshammer Feldspar

A high temperature feldspar for use in white bodies and glazes

3431 Flint

Very refractory material used to provide silica in bodies and glazes. Increases firing temperature and craze resistance but reduces plasticity and shrinkage. In dust form is hazardous if breathed in (see ‘Safety Notes’, page 64).

3432 Fluorspar

A vigorous flux used as a source of calcium in glazes. In low temperature glazes it has a tendency to cause bubbling due to volatilisation of fluorine.

3433 Glaze Binder-Hardener

Glazes for application by brushing generally incorporate up to 5 % of binder. Also useful in 0.5 - 2% addition to avoid colour transference or for maiolica painting. S.C.M.C. Type.

3434 Galena

A natural lead ore used in high lead raku glazes etc. Not suitable for production glazes.

3435 Gum Arabic

Used in water as a medium for underglaze colours and in glazes as a binder.

3436 Ilmenite, fine

3437 Ilmenite, coarse

Generally ‘seeds’ recrystallisation in titania bearing glazes, but in its coarse form will directly produce specks in bodies and glazes.

3438 Lepidolite

A lithium based feldspar useful as a secondary flux in stoneware and porcelain glazes.Limestone. See 3469 Whiting.

3439 Lithium Carbonate

A good alkaline flux used as a substitute for soda and potash when a good craze resistance is required. Provides typical alkaline colour response.

3440 Magnesite

A very high quality mineral source of magnesium carbonate used as a high temperature flux in glazes.

3441 Magnesium Carbonate

Secondary high temperature flux producing a ‘buttery’ or satin matt surface (up to 10%). Excess may cause crawling and pinholing. Improves craze resistance.

3442 Magnesium Sulphate

Epsom Salts. Used to flocculate i.e. Thicken glazes to assist suspension and application to relatively vitreous biscuit ware.

3443 Matting Agent

To give a matt finish to glazes add 5-45% depending upon glaze and degree of mattress required.

3444 Painting-Screening Medium

Outstanding for china painting, excellent for silk screening, but good for general decoration both on-glaze and underglaze. Water based: wash brushes etc. In water.

3444-02 Screen Printing Medium

A thicker bodied medium specifically for screening - use turps for cleaning.

3445 Painting Medium

A superlative painting medium based on resins. For use with enamel colours.

3445-2 Painting Media

A cheaper substitute to 3445 and based on a turps-fat oil mixture.

3446 Underglaze Medium

A new inexpensive, general purpose medium particularly suited for mixing with underglaze colours to obtain painting consistency.

3446-2 General Purpose Medium

Molochite grogs

Calcined china clay. Fine grades (120’s & 200’s) used as clay substitute to lower shrinkage of engobes etc. The coarser grades are used as very pure white grogs.

3447-22 22’s to 60’s white grog

3447-30 30’s to 80’s white grog

3447-120 120’s to dust

3447-200 200’s to dust

3448 Mouldmaker’s Size

High quality size used in production of plaster moulds.

3449 Nepheline Syenite

Mineral mixture of feldspar and hornblende with little silica. More fusible than feldspar it can be used as a replacement to reduce the maturing range of glazes and bodies. Opacifiers See 3467 Tin Oxide and 3476 Zircon. Also 3468 and 3475.

3450 Potter’s Plaster

A selected high quality superfine plaster ideal for the production of moulds. Mixing ratio: 51bs plaster to 3 pints water or 100 to 78 parts by weight respectively.

3450-3 Sculpting Plaster

A firmer plaster designed for sculpting use.

3451 High Density Plaster

A harder setting dense plaster used in the production of block and case moulds. Mixing Ratio: 6.25 Lbs plaster to 3 pints water or 100 to 60 by weight.

3452 Quartz.

Silica Introduces silica and alternative to flint in glazes although not an exact replacement for flint in clay bodies.

3453 Pearl Ash

K2CO3 Potassium Carbonate. An extremely vigorous flux for low temperature glazes.

3454 Rutile

An ore containing titanium dioxide with iron oxide used to produce a mottled buff brown colour (3-8%) especially in the presence of ilmenite. Increases opacity of glaze. Exciting effects may be achieved in combination with stains or colouring oxides

Silica Sands

Used as sand-grog for clay bodies or as placing sand.

3456-1 White Sand No. 1

Medium white sand 30’s - dust.

3456-2 Fine Sand No. 2

Light buff sand 40’s - dust.

3456-3 Buff Sand No. 3

Buff medium, 30’s - dust. An excellent general purpose grog.

3456-4 Buff Sand No. 4

Buff coarse, 16’s-dust.

3457 Silicon Carbide

SiCA finely ground material used as a local reducing agent in glazes to obtain reduced effects in oxidised (electric) firings.

3458 Soda Ash Sodium Carbonate

Used in the preparation of casting slips in combination with sodium silicate. Its solubility in water makes it effective as the alkaline glaze constituent of Egyptian Paste.

3459-1 Sodium deflocculant

A specially formulated liquid blend, easy to use for the preparation of casting slip. Add 200 cc 3459-1 plus I litre water to 10 kg clay (plastic) or 250 cc plus 3 .5 litres water to 10 kg powdered clay.

3459-2 Sodium Dispex

An alternative to sodium silicate. Gives improved stability and mould life. Liquid and easy to use.

3460-75 Sodium Silicate 75tW.

3460-140 Sodium Silicate 100tW

Liquids used in preparation of casting slips by deflocculation.

3462 White Stopping

A filler for cracks in white and ivory biscuit ware. Mix with water to a thick paste.

3463 Buff Stopping

A filler for cracks in buff earthenware or stoneware biscuit.

3466 Talc.French Chalk.

Soapstone. Magnesium Silicate. Secondary flux introducing magnesium (see Magnesium Carbonate 3441) and improving craze resistance of glazes. A flux for clay bodies -especially flameproof and low temperature ones.

3467 Tin Oxide Stannic Oxide

The most reliable, oldest and most widely used opacifier. Produces a somewhat ‘softer’ white and is less refractory (neutral) than zircon. 5-10% usually added for opacification.

3468 Titanium Dioxide

A cream white opacifier often used as a constituent of vellum white glazes.

3469 Wax Emulsion Resist

Used to paint an area of ware over which no glaze is required, the glaze not adhering to the resist which burns away during firing.

3469-2 Wax Resist Pen.

3470 Whiting. Chalk, Limestone

Calcium Carbonate. The main source of calcium in glazes and extensively used as a flux in stoneware and porcelain glazes. Assists hardness and durability and in large quantities produces mattness.

3471 Wood Ash

A mixed grade for ash glazes.

3473 Wollastonite

Calcium Silicate. An alternative to whiting as a source of lime in stoneware glazes. Less dissociation and therefore useful where pinholing is a problem.

3474 Zinc Oxide

The source of zinc and, in small amounts, useful as a flux in middle and high temperature glazes imparting a wider firing range and good craze resistance. Above 10% produces a matt texture under slow cooling conditions.

3475 Zirconium Oxide

An alternative opacifier to Zircon. 5-10% for semi opaque, 10-15 % for fully opaque.

3476 Zircon.Zirconium Silicate

An ultra-fine form of zircon used as an opacifier. Add 5-8% for semi opaque and 10-15% for fully opaque glazes.

3477 Zircon

A cheaper, waterground version suitable for batt washes, abrasion resistant matt glazes etc.

3480 Mender

For mending broken greenware. Moisten greenware, apply Mender, press firmly together and hold for a few seconds and then remove any excess. Also used to fill cracks in biscuit ware: soak cotton fibre in Mender, fill in the crack and refire.

3481 Mask

A latex based product for application to greenware or bisque. On bisque apply 2 coats (wet upon wet). After glazing or decorating, the mask can be peeled off by lifting a corner. It then peels away like any rubbery latex substance. Better than paper masks etc. Handy 2 ounce jar.

3483 Alumide Cement

For glueing broken biscuit or glazed pieces together prior to firing.

3484 Prop-it

Refractory liquid paste for glueing bone china clayware props into position prior to firing. Glue burns away leaving alumina refractory which prevents sticking

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