When animals are exposed to softwood shavings the aromatic hydrocarbons are absorbed through the respiratory tract and enter the blood. The acids given off by pine and cedar shavings are very damaging to the respiratory tract. These acids can actually destroy cells that line the lungs and trachea (2).For a complete summary of the respiratory toxicity of pine shavings, go to. .hen animals are exposed to softwood shavings the aromatic hydrocarbons are absorbed through the respiratory tract and enter the blood. The acids given off by pine and cedar shavings are very damaging to the respiratory tract. These acids can actually destroy cells that line the lungs and trachea (2).
Bowstring trusses are made with a curved top chord and a straight bottom chord. The top chords were originally made with multiple leaf chords where the curvature was cut into the solid sawn chord members.A second style of bowstring truss used glued-laminated chords. The top chord in these trusses was curved in the laminating process.While these trusses have carried the roof load for decades, it is not uncommon to receive calls regarding broken trusses following a heavy snow event.he top chords were originally made with multiple leaf chords where the curvature was cut into the solid sawn chord members. A second style of bowstring truss used glued-laminated chords. The top chord in these trusses was curved in the laminating process.
Some fine synthetic bows are also made of fiberglass and other man made materials. Cheaper bows can also be made of synthetic materials and less suitable types of wood. A bow maker or luthier typically uses 150 hairs for the bows for violin family instruments.Inexpensive bows often use nylon or synthetic hair.Rosin, which is sticky and made from tree sap, is regularly applied to the bow hair so that the bow moving across the instrument's strings will cause the string to vibrate and produce a tone.nexpensive bows often use nylon or synthetic hair. Rosin, which is sticky and made from tree sap, is regularly applied to the bow hair so that the bow moving across the instrument's strings will cause the string to vibrate and produce a tone.