SEASONING TIMBER.

Otago Daily Times, Issue 19952, 20 November 1926, Page 25

SEASONING TIMBER.

AN AUSTRALIAN PROCESS

TESTS MADE AT MELBOURNE. The tests .commenced to season 2000 ft of green hardwood timber in a period of nine days by means of the hydro-vacuum process were completed on November 4 at- West Eootscray (says the Melbourne Age). The test, which was regarded as a severe one because of the nature of the timber used, was supervised by Messrs E. J. Yell and, president of the Victorian Hardwood Millers’ Association; R. T. Patton, of the Melbourne University, and P. J. O’Connor, a city architect, on behalf of a company which has obtained an option over the Australian rights' for the process from the Hydro Vacuum Co. (Ltd.). There was a large gathering ol people interested in the timber trade, as well as Mr E. MacKinnon, of the Council of Scientific and Industrial Research, and Messrs E. Mocking and C. French, jun., State experts. The process also renders the timber immune from the borer, a fact which impressed visitors. The timer stacked in the kiln comprised several different qualities of recently cut, sappy boards, including the soft heart of a tree, and boards cut on the quarter and on the back. They measured from 9in by lin to Sin by lin. The maximum proportion of moisture content was given as 124 per cent., and the minimum as 104 per cent. The test boards were well distributed throughout the stack to ascertain what the extent of the seasoning was in various parts of the stack. When the kiln was opened it was found that the evaporation of moisture in parts of the stack had not been quite so extensive as it was thought it would be. While the boards on the outside of the stack seemed to have had a substantia! amount of moisture extracted from them, those in the centre did not lose nearly so much, although precautions had been taken to ensure complete circulation by placing sticks between each board. This result __was attributed by the inventor (Mr A. Kobiolki) and by other experts to the vacuum, which withdraws the atmosphere and creates the evaporation in the kiln, not being at a sufficiently high pressure. The pressure was about 131 b to the square inch, which is the capacity of the pump attached to the plant. It is considered that by increasing the pressure to between 141 b and 151 b the expected results — the complete seasoning of the timber right through the stick —will bo obtained, as well ns eliminating the cracking of some boards by reducing the beat. The outside boards and the ends were fairly well seasoned, though here boards cut on the quarter seemed to respond more satisfactorily to the treatment than those cut on the back. The test was by no meqns regarded as a failure by most of those present—in fact, many who were seeing the process for the first time expressed the view that there were great possibilities before it when the plant is completely equipped. With specially selected boards, one timber man considered the jcsults even with the smaller pump would _ effect considerable changes and savings in the seasoning of timbers, which now take from one to three years, according to size, by the open-air ruck system, though by racking the timber and using a hot-air kiln the timber is now dried in about four months. 'But it has to first be left in the racks for at least three months. With the hydrovacuum process the inventor is confident he will be able to dry it in nine days on a commercial scale. ’The report on the results of the tests from a scientific point of view will not bo available tor" about a week. It is proposed to slightly remodel the pumping apparatus, and to make further tests later. Mr Rayno, chairman of the Hydro Vacuum Company, thanked those who witnessed the completion of the test for attending, and said the aim was to season the boards in nine davs. Mr Kobiolki briefly explained the process of extracting flic atmosphere and creating evaporation, and Mr MacKinnon referred (o the experiments made in the fumigation of dried fruits lor a trial shipment to London. .