Escol Products Ltd

Escol Products Limited, a member of the Stewart & Gray Group of Companies, is the longest commercially established frit manufacturer in the United Kingdom and a leading supplier of frits and oxides for vitreous enamelling worldwide.

The original company J F Stewart was established in 1919 with manufacturing facilities in Stratford, London.

It was founded by William Thomason, whose pioneering work in introducing leadless enamels into the ceramic industry paved the way for the production of leadless frits for vitreous enamelling.

During the late 1920s, J F Stewart worked closely with J Gray & Sons, who were specialist engineers servicing the enamelling industry. It was at this time that Escol was first used, a name which subsequently became the registered trade mark.

In 1933 following continual increasing demand for Escol frits the company moved to a new site in Tooting, London where they retained a presence for the next thirty-seven years.

In 1942 J F Stewart amalgamated with J Gray & Sons to form Stewart & Gray Limited.

I n 1945 with the expansion of the vitreous enamelling industry, Stewart & Gray quickly became one of the largest contract enamellers in the country, specialising in the enamelling of cast iron and steel. Frit manufacture also grew rapidly, particularly for overseas markets and in 1955 a separate specialist company, Escol Products Limited, was formed for the manufacture and sale of frits, oxides and miscellaneous materials.

By the early 1960s, the Tooting site had become too small to accommodate both companies and as a result of this, in 1964, Escol Products Limited moved to a new purpose-built factory in Huntingdon, Cambridgeshire.

Stewart & Gray continued for a while in London developing their expertise particularly in the growing use of vitreous enamelled architectural building panels. In 1970 they also moved to a purpose-built factory in Wellingborough, Northants, and are now established under the name of Escol Panels (S & G) Limited, having emerged as one of the leading manufacturers of vitreous enamelled steel architectural building panels in the world. All their specialised frit requirements are supplied by Escol Products Limited for probably what is one of the most demanding applications for vitreous enamel.

Stewart & Gray Limited remains a family owned and managed company and acts as the holding organisation for the Group.


At Escol all these frits and enamel powders are fully tested and approved by a team of experienced chemists to rigid standards. A continuing research program seeks to improve existing frits and develop new frits to meet the demands of the industry.

The smelting of Escol frits is carried out in specially designed kilns where temperatures can be in excess of 1200 C. In order to achieve homogeneity and consistent results, all frits are smelted to a specified cycle. The frit melts are water quenched and then dried in special rotating drums.

All frit bags show a date and batch number, which is essential for record purposes and retracing technical information after the consignment has been dispatched. Samples of each batch are kept at Huntingdon for approximately 6 months as part of a complete technical back up service for customers.

Powder Classification: the process of producing dry electrostatic vitreous enamel powders


Powder treatment: the process of producing dry electrostatic vitreous enamel powders

Escol, in keeping with its position internationally, has invested in large scale development of electrostatic powder vitreous enamel coatings. Plant installed includes a continuous electrostatic spray line for test coating clients' production components such as hob-tops as well as for internal research and development purposes.

To ensure optimum application performance of electrostatic powder, the correct particle size distribution must be maintained and is controlled by classification and fluidised bed techniques. Testing is carried out using Coulter counter equipment.





A continuous electrostatic spray line for test coating clients' production components and for research and development at the Huntingdon factory


Other developments include the production of ground coat frits to suit environmental requirements such as no pickle and no degrease finishes. Apart from the savings achieved in steel pre-treatment, there are also reduced effluent disposal problems with this type of application.

Where production capacity problems exist, the Escol two coat one fire system is advantageous. Since one complete firing is eliminated this also has the potential to generate cost savings. Special frits are also available which have been developed to meet the relevant DIN and ISO test standards for application to domestic hot water tanks.

A spectrophotometer with integrating sphere for colour measurements and control

As well as the manufacturing facilities, the Huntingdon site has specialist laboratories for Quality Control, Research & Development, Powder Development and Colour Matching

Special attention is paid to individual customer requirements in solving their enamelling and related problems and full technical reports on specific difficulties are prepared and submitted. This involves such areas as cross sectional views through vitreous enamelled steel or cast iron products for visual evaluation. The colour matching facilities include the use of a spectrophotometer with integrating sphere for accurate colour control.

Close-up of a cross sectional view through a fault in an enamelled cast iron product. Microphotography and its interpretation is an essential part of our customer service facilities

The Company's principal customers are major manufacturers of domestic appliances, baths, sinks, holloware, architectural building panels, silos, hot water tanks, contract enamellers and specialist applicators in many different countries around the world. In recognition of its achievements in overseas markets the company has received the Queen's Award for Export.

Consistent with its leading role in the industry and the highest standards of vitreous enamel frit production, the Company has obtained the BS EN ISO 9002 quality standard.



Quality Approved Products
BS EN ISO 9002 1994
Certificate Registration No. FM09044

Escol Today Vitreous enamelling is an ancient art which has survived and been transformed in contemporary times into a unique protective and decorative coating for metals.

It is one of the most durable of all finishes and essential to the vitreous enamel is the quality of the frit. This is a glass product formed from a wide range of raw materials which includes Borax, Feldspar, Cobalt, Nickel, Titania and many others.

Escol Products Ltd.

Copyright © 2000 AKA ChemTech - Tony Abouhamad
Last modified: 15 June 2000


Tel. +963 41 466671

Fax +963 41 469882

P.O. Box 175 Lattakia - SYRIA