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Basic Wood Joints. Mr. Rodriguez Ag Mechanics. 1. Butt Joints. Butt joints are formed by joining two boards end to end, or edge to edge. ( in a line or right angle)
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Basic Wood Joints Mr. Rodriguez Ag Mechanics
1. Butt Joints • Butt joints are formed by joining two boards end to end, or edge to edge. ( in a line or right angle) • Butt joints can be reinforced by fastening thin wood or metal gussets to the corners or across the flat surfaces where the boards join.
2. Lap Joints • Lap joints, which are stronger than butt joints are formed joining two boards face to face. • Lap joints can be strengthened by offsetting the boards so they fit into each other.
3. Dado joints • A dado joint is a rectangular groove cut into a board. • Dado joints are formed by inserting the end or edge of another board into this groove.
4. Rabbet Joints • A rabbet is a rectangular groove cut in the end or edge of a board • Rabbet joints are formed by inserting the end or edge of another board into this groove.
5. Miter Joints • Miter joints are formed by cutting the ends of two boards at a 45°angle and joining them to together to form a 90° angle. • Miter joints are usually stronger than butt joints because they provide more surface contact at the joint.
Fastening wood joints with nails • Hammers: • There are two types of hammers commonly used. • The curved claw hammer, designed to pull nails. • The straight claw hammer, the straight claw can be driven into the wood like a chisel, to pry them apart.
What size hammer do I need? • Depending on your needs, a hammers size is determined by the weight o fit head. • Curved claw hammer @ 13 oz. • Straight claw hammer @ 16 – 20 oz.
Driving Nails • Follow the steps to drive a nail perfectly every time! • Hold it between thumb and index finger • Place in desired spot • Place fingers high on the nail, to allow them to be knocked free rather than smashed! • To prevent splitting, use a smaller nail
Nail Driving cont. 5. Grasp the hammer near the end of the handle, with your free hand holding the nail. 6. Using only wrist action, use the weight of the hammer head to do the work, use elbow action for extra work. 7. Continue to drive the nail until its head is flush with the surface.
Pulling Nails • If your nail head extends above the surface of the wood, go ahead and slip the claw under it. • If it is flush with the surface, use a pair of pincers or a cloven nail puller to extend the nail head far enough to the claw under it. • Pull the handle of the hammer until it is perpendicular to the surface, then stop. • Place a block of wood under the head of the hammer, then continue to pull the handle until the nail is removed!
Using Screws • Measure the thickness of the boards to be joined. • Select a screw usually 3 times as long as the thickness of the boards being joined, if it extends beyond the second board, select a shorter one. • Use a pilot hole that is smaller than the diameter of the screw • Clamp the boards together • Using a screw driver or screw bit turn the screw until the two boards are joined together snugly, but do not over tighten the screw.
Fastening with Bolts • Select the type of bolt required, usually a carriage bolt since it is designed for wood. • Select the diameter and length of required. • Clamp the two boards together and drill a hole the same diameter as the bolt • Place a flat washer on the threaded end of the bolt. • Place a nut on the bolt and turn it until it is tight and the boards are joined together. ( be careful not to draw the bolt below the woods surface.
Fastening with Glue • Make sure the two boards have a good fit and that they are clean of dirt, dust, wax, etc. • Drill screw or bolt holes if required. • Apply a small bead of glue on both board’s mating surfaces. • Spread the bead of glue evenly over the mating surfaces. • Join the boards together & secure them with nails, screws, or bolts.
Fastening with Glue cont. 6. Align the joint properly and retighten the clamps used 7. Using a putty knife or wood chisel, remove the glue that runs after they have partially dried. 8. Wipe the glue marks with a wet rag, and then wipe them again with a dry rag. 9. Take the clamps off after half and hour, but the strongest bond occurs after 12 hours.