GROWING DYED WOODS.

Hawera & Normanby Star, Volume XLII, Issue XLII, 18 October 1922, Page 2

GROWING DYED WOODS.

; 9 COLOUR MIXING WITH SAP. TESTING BY SAWDUST. Neither the process of melting wood j nor that of hardening soft timher prove half so interesting to the casual observer as watching nature produce coloured trees. In growing coloured timber, so that stain, varnish, and paint are unnecessary, the trees -ar© | usually operated upon in spring. This j is because the sap and mineral matter is then more {readily absorbed by the tissues of the trunk and branches. After the various tints or colourings are decided upon, a slanting hole is bored (says "A Backwoodsman" in the Daily Chronicle) through each tree about a foot from the g>round. In the lower end of the hole a short wooden plug is driven. Before the air has time to dry up the sap in the' newly-made hole, a cocentrated solution of aniline dye is forced through by means of a rubber hose and a hand pump. The result is that the dye, on mixing with the sap, circulates throughout the tree and colours the wood. s With the exception of a few trees, a pumpful of dye every two or three hours is sufficient. Some of the large trees will" soak up a gallon a day. Others need little more than a, pint a day. In every case the amount of dye standing in the slanting hole serves as a guide. As might be expected, the first part of the tree to stain is the outer layer of wood. This becomes nicely coloured in about three days. The remaining time is taken up by the dye> spreading to the tree centre. To determine if the 'colouring is', effectual throughout, augurs are driven into the branches at j different heights and microscopic ex-1 animations made of the sawdust. Variation in the shades of the saw-; dust reveals if the process of colouring is incomplete. For example, too much white indicates streaks. This is due to insufficient dye. Where "felled" timber is to be coloured the process is somewhat lengthy. Providing such timber as birch, oak, elm, pine, or spruce is freshly cut, it may be effectually dyed by burial in loamy soil to a depth of four or five feet. Lime and aniline dyes are then poured on the top soil. In this position the wood is left for ' four or five months, and various applications of dye and lime are administered at regular intervals. In this way the wood buried underneath becomes impregnated, with the colouring matter. On being dug out and dried the wood is slightly harder than otherwise, and, if anything, a trifle heavier.