The other later reproducers (such as C) were only designed for the harder black "wax" records. A later reproducer would shave down the grooves very fast, and the sound would be lost forever. In late 1888, metallic soaps were tried. At first, a lead stearate was used, but in the summer months, these records started to sweat and decompose. In 1889, Aylsworth developed an aluminum wax, using acetate of alumina and stearic acid with sodium hydroxide added as a saponifying agent. It was found these records were much more durable. Problems arose, however, since there was no tempering agent and hot weather caused these records to decompose. Two problems contributed to this, stearic quality varied from different makers; Aylsworth purchased some from Proctor & Gamble and found it contained too much oleic acid. Stearic acid without a tempering agent takes on moisture, and after many experiments, it was found that Ceresine was ideal. To make the wax hard, sodium carbonate was added. Even so, a few batches of records still had problems and became fogged. The fog problem arose from acetic acid left in the wax and was solved when higher temperatures were used to make sure the acetic acid was boiled out of the wax. As such, the records from 1889 to 1894 are a reddish-brown color due to the long cooking time. By 1896, Edison started using hydrated alumina in place of acetate of alumina. The use of hydrated alumina (sheet aluminum dissolved in a mixture of sodium carbonate, sodium hydroxide, and distilled water) made better records, and the wax could be manufactured in a shorter period of time. Using hydrated alumina resulted in more desirable blanks, with fewer defects and shorter production time. The Columbia Phonograph Company used Edison recording blanks until 1894. The North American Phonograph Company was dissolved in the fall of 1894, and Edison quit supplying blanks to Columbia, who had purchased 70,000 blanks from 1889 to 1894. Columbia was frantic to find a solution to make cylinder blanks in-house, and the recipe for making Edison's wax was a well-kept secret. Thomas MacDonald experimented with wax alloys with poor results: the records fogged or decomposed in the summer, just like the early Edison blanks. The Columbia company had a deadline to either supply recordings, or have their contracts canceled and be sued for loss of records. Columbia resorted to hiring old Edison Phonograph Works