Presentation on theme: "WOOD WOOD IS MADE UP OF FIBERS AND CELLULOSE. ANGIOSPERMS AND GYMNOSPERMS. GYMNOSPERMS – CONIFEROUS,EVERGREENS CONE BEARING, NEEDLELIKE LEAVES SOFT WOOD."— Presentation transcript:
WOOD WOOD IS MADE UP OF FIBERS AND CELLULOSE. ANGIOSPERMS AND GYMNOSPERMS. GYMNOSPERMS – CONIFEROUS,EVERGREENS CONE BEARING, NEEDLELIKE LEAVES SOFT WOOD HIGHEST TREES;85-110 MTS PINE,CYPRESS,FIR,SPRUCE 650 SPECIES
Like all living things, trees are susceptible to disease. A tree needs a good supply of light, water, carbon dioxide and nutrients from the environment for optimum growth. A lack of one or more of these may lead to reduced growth and put the tree under stress. If a tree is stressed then it may not have the energy required to manufacture important defenses and can become vulnerable to disease. If a diseased tree eventually dies it can sometimes be difficult to diagnose the original cause because problems are often complex and cumulative. For example, a tree could be weakened by drought and then become the victim of a fungal attack; environmental factors such as temperature, storm wounds or pollution may play a part; or sometimes more than one disease may be present. Tree disease can stem from fungal, bacterial or viral sources.
Oak decline is a syndrome in which bacteria, along with insect infestation or weather damage, interact to bring about a serious decline in tree condition. There are two kinds of decline: acute and chronic. Acute oak decline affects mature oaks and bacteria causes stem bleeding where dark, sticky fluid oozes from cracks in the tree trunk. Chronic oak decline may take many years to kill a tree. Symptoms include deterioration of the foliage; leaves may be smaller than normal, pale or yellowish. In some cases the foliage may be thinly spread over the entire crown and death of twigs and branches follow. OAK DECLINE
Amillaria Root Rot The disease attacks hardwoods and softwoods and kills shrubs, vines, and forbs It commercially destructive, a major cause of oak decline. The Armillaria can kill trees that are already weakened by competition, other pests, or climatic factors. It can also infect healthy trees, either killing them outright or predisposing them to attacks by other fungi or insects. Powdery mildew is a common disease that appears as a white powdery substance on the leaf surface. The powdery appearance comes from millions of tiny fungal spores, which are spread in air currents to cause new infections. It attacks all kinds of trees.
Sudden oak death It is caused by a fungus PHYTOPHORA and has killed thousands of oaks in North America and Europe.It causes a bleeding canker on the stem
Heart rot is a fungal disease that causes the decay of wood at the center of the trunk and branches. Fungi enter the tree through wounds in the bark and decay the heartwood. The diseased heartwood softens resulting in trees being structurally weaker and prone to breakage. Heart rot is all throughout the world affecting all hardwood trees and can be very difficult to prevent. An indication of heart rot is the presence of mushroom or fungus on the tree.
FROST CRACKS Frost cracks are due to quick changes in winter temperatures They are vertical cracks in the stems of trees. On sunny days in the winter, bark will warm up, causing cells to expand in the bark and wood directly below the bark. As the sun sets, temperatures drop quickly, causing the bark to cool and contract. The wood under the bark does not cool as quickly, causing the bark to split. Once damaged, the injured area can split back open on very cold, winter days.
Olive tree tuberculosis is a disease found on Olive trees in Spain that is caused by the bacteria Pseudomonas syringae. When this bacteria is introduced into a wound on the tree caused by hail, pruning or by the beating of the branches to harvest the Olives it results in the formation of a like formation that starts off round and light brown and then grows into an irregular wart shaped canker that ends up with a dark brown color and very hard.
WOOD DISEASES INVESTIGATION Make an investigation about wood diseases (8) Add information and pictures of each. Send it a week from today or hand it printed. Individual- Can’t have 2 exact investigations. 16 pts.
Wood decay Wood decay begins with any injury that breaks through the bark and exposes the wood. The injury may be the result of a weed whip, animal damage, broken branch, etc. The damaged cells undergo chemical changes and become discolored. Many microorganisms land on the surface of the wound. Some of these organisms, commonly referred to as pioneer colonizers, begin to grow and colonize the wounded tissue.
Fungal decay: Brown rot White rot Bacterial,fungi, viral infections: Stem bleeding fungi FUNGI
HUMIDITY- SAP Sap is the juice that feeds plants with all dissolved substances and circulates in the vessels. When wood is cut there is humidity in its vessels so it must dry to be used. If NOT dried in a proper way and then used in any type of work,it will suffer distortion later on.
NATURAL DRYING Oldest and simplest way Takes longer time and space Can be dried outdoors or indoors. OUT DOOR DRYING Depends on the weather condition. Must be prepared during the rainy season since it’s when wood has less sap because it concentrates in the root. Should not be left on floor because of fermentation and humidity. A piling system must be used where air can circulate among the pieces drying them.
NATURAL ACCELERATED DRYING PLACING WOOD IN WATER TO DRY SAP AND ELIMINATION OF SALTS. IN SOME PLACES IT IS PLACED IN RIVERS AND AT THE SAME TIME IT IS TRANSPORTED TO ANOTHER PLACE. SOMETIMES WOOD DARKENS SLIGHTLY. INDOOR DRYING TWO MONTHS AFTER BEING CUT WOOD IS PLACED INDOOR WITH PLENTY OF VENTILATION.
DIFFERENT TYPES OF GLUE When two pieces are united with nails,screws,joints sometimes they also need glue.There are hot,cold and with casein. GLUTIN GLUE :made from residious materials of animals;pieces of skin,bones,cartiledges.They are heated at high temperatures and are resistent. SYNTHETIC RESIN GLUE : they are bought already prepared. More resistent than others.Resistent to humidity,putrefaction and mold. CASEIN GLUE : made from milk.Sold in powder,or solid, very resistent and stand humidity.
Paint components Pigmen t: provides color (also can provide corrosion resistance, water barrier properties, viscosity control. They can be found throughout nature in clays, herbs, nuts, berries, barks, carbon, charcoal, and soot. They are ground down into powder and usually boiled several times in water to remove impurities. Binder (resin):Binds the ingredients (holds everything together), Natural binders are chalk, lime, casein (non-fat milk curds), animal or vegetable glues, and oil. Lime has antibacterial qualities and is used for interior or exterior walls Casein is the binder for milk paints; it is used for interior walls and for fine arts. Animal and vegetable glues make chalky paint and are usually used in fine arts. Oil is used for woodwork paint and fine art. It "binds" the pigment together, and provides film integrity and adhesion. Volatile vehicle (solvent or dispersant): dissolves or disperses the binder, allows the coating to spread out.
Paint Components Binder (resin):Binds the ingredients (holds everything together), Natural binders are chalk, lime, casein (non-fat milk curds), animal or vegetable glues, and oil. Lime has antibacterial qualities and is used for interior or exterior walls Casein is the binder for milk paints; it is used for interior walls and for fine arts. Animal and vegetable glues make chalky paint and are usually used in fine arts. Oil is used for woodwork paint and fine art. It "binds" the pigment together, and provides film integrity and adhesion.
CARRIER/VEHICLE/SOLVENT/LIQUID It provides desired consistency and makes it possible to apply the pigment and binder to the surface being painted. The main purpose of the vehicle is to adjust the viscosity of the paint. Water is the main vehicle for water based paints. ADDITIVES These are low-level ingredients that provide specific paint properties such as mildew resistance, good flow and levelling. Some examples include additives to improve pigment stability, control foaming, control skinning, etc. Other additives might be thickeners or biocides to fight bacterial growth.
PAINTS ACCORDING TO THE GLUTINOUS, PAINT CAN BE DIVIDED INTO THE FOLLOWING GROUPS: QUICK LIME PAINT – CALCIUM OXIDE GLUE PAINT WATER PAINT OIL PAINT LACQUER : varnish made from sap of certain trees
4’s 4 types of binders 4 things used for pigments 4 ways of artificial drying 4 components of paint 4 characteristics of angiosperms 4 characteristics of gymnosperms 4 types of paints 4 things additives do
SEALERS &VARNISHES Every wood has pores; some have them big and others small. So it must be smooth before finishing the product.This is obtained by sanding the wood with different types of sand paper,some are coarse while others are fine. At the same time some stains or scratches can be eliminated. There are two types of sealers; resine and sillicone. After sanding, the sealer must be applied.It must dry up and then sanded again until no signs of sealer show up. Add another coat of sealer and when it is dried add varnish. Varnish needs to be diluted,some in turpentine, others in thinners.
. Varnishes are transparent with no pigment and are diluted before using them. Varnishes also known as lacquers add beauty and protection to wood. There are many different types of lacquers ; oil, alcohol, nitrocellulose, plastic etc. Some have sheen tones;not so glossy, from ultra matte to high gloss. Today varnishes can be found in sprays or in brush on styles.
WAYS OF PAINTING CLOTH METHOD This is the oldest way of painting where a ball is made with a piece of cloth-preferably T-shirt and it is tied at the end. It is dipped in paint and applied in circular form repeating the process when each layer is dried. BRUSH Nowadays this way is not very popular. Big areas should be covered with big brushes while small areas should be covered with small brushes. GUN The most popular method because it gives a very nice finish to the piece. It is the fastest method.
JOINERY- JOINTS Joinery often refers to the part of wood working that involves the joining together of parts of wood. Traditional wood joinery techniques often work without mechanical fasteners. There are different types of joinery for different structures, for example the joinery used to build a house is different from that used to make certain toys.
Butt joint A butt joint is when one piece of wood butts into another (most often at a right angle, or square to the other board) and is fastened using mechanical fasteners. This type of joint is often used in wall framing on construction sites
Mitered butt joint Mitered butt joint It is the same as a butt joint only that the 2 pieces of wood are joined at an angle. HALF LAPP JOINT MORTISE AND TENON JOINT one of the strongest joints.Mostly used in tables and chairs.
BRACE MORTISE AND TENON USED IN A DIAGONAL WAY TO HOLD TWO OTHER PARTS.
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