Production

Ultramarine is made from a finely ground mixture of china clay, sulphur, soda ash etc. Before more modern automated methods were introduced grinding was accomplished using a dry-ball mill.

Original Ball Mill now on show outside the Whitewater Hotel, this was the little ball mill. Photo Ron Mein 2005

The ground powder was then loaded by hand into crucibles which were locally called pots. The pots were stacked in kilns which were heated by coal fires to a temperature of approximately 800 degrees for three days, which baked the contents of the pots into a dull green block.When this stage was completed the firing was stopped and the kiln was sealed to ensure it was air tight, and then allowed to cool over a period of about two weeks. During the cooling period oxidisation took place and the blocks gradually turned into a rich dark blue colour.

After the blocks had been off loaded from the kiln’s they were crushed and thoroughly washed by slurring it in hot water to remove the unwanted impurities of sodium sulphate also known as Glaubers Salts. The washed raw blue was then loaded into a wet ball mill and ground for a period of 48hrs or more, after which the very fine blue suspension was pumped into a series of settling tanks which separated off several shades of blue that were then dried in hot air driers. The various shades would later be blended to meet customer requirements, and each shade of blue was guaranteed to be the same every time.

The final ultramarine product was packed and dispatched from the mill in various sized containers, 1/2 cwt (25 kg) five ply paper sacks, 1 cwt (50kg)Plywood kegs, 2 ½ cwt (125 kg) steel drums and up to 1958 wet paste blue was sold in barrels weighing 5cwt ( 250 kg ).

In 1942 the Hull factory was bombed, destroying their carton filling department, and the Backbarrow manager persuaded Reckitt’s to transfer the carton-filling process to Backbarrow, which became known a Kendal Road. Production of the small blocks of laundry blue known a Dolly Blue remained in Hull, and contrary to popular belief Backbarrow never produced the proprietary item known as Dolly Blue.

These full size models were made by Ron Mein for the Lakeland Motor Museum local history displays. 2010.

A large portion of the production was transferred from the main mill to the Kendal Road carton filling and dispatch department were the product was packed in the various size cardboard cartons with weights ranging from 1 oz, 30 gm, 250 gm, 450gm and 1 lb (500 gm). The packed cartons were then wrapped in paper with the product brand printed on, the brands were Robin, Seagull , Crown and Destree( for french speaking countries) . Wrapped cartons were then packed in wooden boxes made locally by George Barker and Son, after 1957 the boxes were replaced by fiberboard boxes which could be sealed with sticky tape. The filled boxes were stored in two large wooden huts to await dispatch,(in 1976 a very large  store was constructed with an asbestos roof). Large quantities of boxes were transported by rail from Haverthwaite railway station but the bulk was transported by road to Liverpool docks by Athersmith Brothers of Barrow in Furness, often the eight wheel lorries also pulled trailers.