Choosing the Right Type of Wood Glue

When shopping for adhesive, you’ll see pretty quickly that there’s not just one type of wood glue—rather, there are five main varieties. Most wood glues are synthetic polymers or resins that are stronger than the wood itself, one exception being hide glue, which is made of animal collagen. In addition to makeup, these glues also differ in terms of bond durability, flexibility, toxicity, and waterproofness (some may even affect your wood’s finish more than others).

Polyvinyl Acetate (PVA) is a rubbery synthetic polymer that creates a flexible, permanent bond.

This wood glue is non-toxic (except when ingested), water-soluble (thinned by stirring in small amounts of pure water), and ideal for a wide range of projects, especially for non-structural wood-to-wood bonds. White varieties of PVA are designed for indoor use, while yellow varieties (also called “carpenter’s glue”) are formulated for outdoor use. If you need a water-resistant glue, always check for “waterproof” on the label.

PVA will leave a residue, affecting your wood’s finish—especially oak. Another drawback is that PVA does not accept wood stain very well. If you try to stain the dried glue, it will look patchy. Make sure you wipe away any excess glue with a Q-tip or sponge before it is dry. For best results, press the pieces of wood together with a clamp until the glue is dry. If clamping is not possible—for example, if you want to glue a wood plug into a screw hole—add pressure by hand for a few minutes. Then allow air circulation (from an open window or fan) to create a strong bond. Know that PVA glues are basically permanent; once dry, the glue cannot be reversed or removed for repairs.

Polyurethane is a synthetic plastic resin that creates tight, lasting bonds.

Used for everything from paint to wood floor finishes, polyurethane is also a major ingredient in many wood glues. These wood glues excel when joining wood grain end-to-end—for example, if you need to connect two pieces of crown molding—forming flexible, durable joints. Polyurethane is moisture-activated, meaning it relies on the moisture in the air to set to set, so it bonds very well in humid conditions unlike other wood glues and doesn’t dry out sensitive wood fibers.

This toxic chemical needs to be handled with care. Always work in a room with good ventilation, and wear a face mask and goggles to avoid inhaling glue fumes. If you intend to stain your wood, know that polyurethane goes on more easily than PVA. Still, remove any excess glue with mineral spirits—water is not strong enough.

Cyanoacrylate (CA) is a quick-drying acrylic resin—and another name for superglue.

Once cured, these bonds are very hard and rigid, which is helpful if you only need to create a temporary bond—a couple taps of a hammer or mallet will break it. CA glue can be used to apply glue blocks, or short strips of wood designed for reinforcement, to the back of a fresh furniture joint for as long as they’re needed. It also comes in handy for filling cracks when mixed with sawdust.

Unlike other wood glues, CA glue will not bond to a dry wood surface and requires the wood be slightly damp before application. It does, however, bond almost instantly at room temperatures, so it should be handled with care and precision. Wear a mask and protective gloves when working with the runny, water-like glue; if any glue touches your skin, remove the superglue with acetone (nail polish remover). Acetone can also be used to remove excess super glue from your work surface, but this chemical solvent can also damage your wood finish if not used carefully. Its short shelf life means that CA glue will only work on near-term projects, good for about a year when sealed but as little as a month after opening.

Hide glue is the all-natural choice for wood furniture repair.

Basically boiled animal collagen, hide glue comes in two forms: liquid and solid crystals that are melted in a hot water bath and applied with a brush. The liquid (room-temperature) hide glue utilizes urea crystal additives to keep it fluid and allow more time to work. Hot glue, in contrast, will cure as it cools soon after application. Today, woodworkers choose both forms of hide glue primarily for the leeway (i.e. reversibility) it offers as it dries and its natural, lubricating properties. It creates lasting, yet flexible joints—which is why many antiques are still repaired with hide glue. Using this adhesive preserves the quality of antiques and honors traditional craftsmanship.

In liquid form, hide glue gives you more time to perfectly fit two pieces of wood. When fully set and dried, it is an excellent choice for furniture construction and other tight, lasting bonds. Both types of hide glue are often used in guitar and stringed instrument construction. Best of all, it won’t harm your wood’s finish.

Epoxy is the best wood glue for filling in gaps and cracks.

Unlike the liquid texture of other wood glues, epoxies thicken to a putty-like consistency. This wood glue is a two-part formula, consisting of a resin and a hardener that interact right at the time of application. Once cured, epoxy’s durability and waterproofness make it favored by woodworking experts. For example, epoxies are often the go-to wood glues for joining wood in boats and sailing vessels.

Epoxy glue works best with clean, dry, and sanded surfaces. First, wipe your wood with an appropriate cleaner to remove any dust, waxy build-up, or other residues. Next, gently buff the surfaces with paper towels and air-dry fully. Finally, make sure your wood is sanded and ready to join. Then you can mix your two-part epoxy and apply according to package directions. Have a wood clamp handy if you are joining two surfaces. While epoxies are considered non-toxic, they are irritants and can cause rashes and burns. Wear gloves and keep your hands away from your face and eyes.

Furniture refers to movable objects intended to support various human activities such as seating (e.g., chairs, stools, and sofas), eating (tables), and sleeping (e.g., beds). Furniture is also used to hold objects at a convenient height for work (as horizontal surfaces above the ground, such as tables and desks), or to store things (e.g., cupboards and shelves). Furniture can be a product of design and is considered a form of decorative art. In addition to furniture's functional role, it can serve a symbolic or religious purpose. It can be made from many materials, including metal, plastic, and wood. Furniture can be made using a variety of woodworking joints which often reflect the local culture.

People have been using natural objects, such as tree stumps, rocks and moss, as furniture since the beginning of human civilisation. Archaeological research shows that from around 30,000 years ago, people started to construct and carve their own furniture, using wood, stone, and animal bones. Early furniture from this period is known from artwork such as a Venus figurine found in Russia, depicting the goddess on a throne. The first surviving extant furniture is in the homes of Skara Brae in Scotland, and includes cupboards, dressers and beds all constructed from stone. Complex construction techniques such as joinery began in the early dynastic period of ancient Egypt. This era saw constructed wooden pieces, including stools and tables, sometimes decorated with valuable metals or ivory. The evolution of furniture design continued in ancient Greece and ancient Rome, with thrones being commonplace as well as the klinai, multipurpose couches used for relaxing, eating, and sleeping. The furniture of the Middle Ages was usually heavy, oak, and ornamented. Furniture design expanded during the Italian Renaissance of the fourteenth and fifteenth century. The seventeenth century, in both Southern and Northern Europe, was characterized by opulent, often gilded Baroque designs. The nineteenth century is usually defined by revival styles. The first three-quarters of the twentieth century are often seen as the march towards Modernism. One unique outgrowth of post-modern furniture design is a return to natural shapes and textures.

Framing

• 1 First the frame is constructed from wood that has been found clear of any defects. The thickness of the wood should allow for the heavy tension webbing to follow. If the frame is not sufficiently strong, it will not bear the weight redistributed into it by the webbing whenever someone sits down. Arms, back, or back sections, seat, and legs are attached. The preferred method is with clean-cut, fitted double doweled glue joints reinforced with comer braces, glued and also screwed into place. Each major part of the sofa will have to have springs attached separately, and also be padded separately. Consequently, they are "framed out" with reinforcing slats, arranged around the seat section.

Webbing and springs

• 2 The foundation is then set for padding. Jute, a kind of burlap made in India, is used as webbing. Strips of this material are interwoven, stretched across the frame, and tacked down. Flax twine is then used to strap the springs onto the webbing. Two lines of twine are tacked into position and then tied around a spring back to front. Another pair of lines will run side to side on each row of springs after all the springs have been lashed into position individually. If heavy-gauge springs are used in the "front row," these are further tied down with a length of wire. This process is repeated for the back, with special attention to the springs at the base, which are treated like the front row of seat springs. If the back comes in sections (sometimes three for design purposes), then each part is separately tied off and the twine ends tacked onto the four-sided frame. The same is true for any sides and arms. Each part will be wrapped in its own sheet of burlap after being completely fitted with secured springs. The burlap is cut to size for each part, tacked into place initially, and then tightly lashed to the springs to minimize movement. This is to prevent the springs from wearing through the burlap over time.

Padding

• 3 Each part is separately padded as well, with layers of burlap and horsehair or chosen synthetic material. The padding is placed in a burlap envelope, arranged on the edge of the seat, pinned into place, and stitched down. As the stitching progresses, the pins can be removed one by one. This roll is then shaped according to design requirements and stitched with special needles and more twine. After this is secured yet still pliable, a layer of about 15 lb (6.81 kg) 
  
  of padding is distributed over the whole area of the seat, extending over the roll. The layer is basted into place with long, loose stitches and covered with lighter weight burlap. Tighter stitching divides the seat into two areas called the platform and the nose or front edge. This front part is reshaped with hand stitching. After the shaping is completed, a final, thicker layer of padding is added to fill in dips left by stitching in the burlap, and basted like the previous layer. A muslin sheet of covering is applied, stitched into the break between the platform and nose, tightened across the front edge and back across the platform; its edges are tacked into place. Anomalies in the padding are addressed before proceeding.
• 4 The arms are done next in the same basic fashion. Layers of padding and burlap are fixed in succession and topped with muslin. The arms also have a front edge of extra thick padding. Once the arms are properly shaped the back or back sections may be padded. If there is more than one part to the back, the center is padded first up until the second burlap layer. Then, the two flanking sections are padded up to that point, to match the center in size. The edge roll is formed around the top and back of the crest rail or uppermost part of the frame, or the corresponding area of each of the back parts, each of which must be kept parallel to the others. After inspecting and making any adjustment to the padding, the exposed wood parts can be stained and finished to taste or design specifications.

Fabric

• 5 Every piece and panel that will be fabric covered must be measured and recorded in a cutting list. The fabric is purchased in one piece or lot. The panels are then plotted out in chalk so they match wherever their seams will meet when finally applied. If any of the panels and pieces need to be sewn together before being attached to the padded frame, this is taken care of first. The seat is covered with panels for the platform and nose and hand-stitched into place along the break between them over a layer of cotton batting. The nose is then covered first to check if the pattern continues along the front properly. The covering is fitted over the back or platform end and secured. The arms are covered next after being prepped with their own layers of cotton batting. A fan-pleated arm is a classic look. The fabric is folded into place around the front roll, in a series of pleats that look like an opened fan when finished. A series of strategically placed cuts may be made, so the fabric clears all obstructions presented by the frame. The top, bottom, back, and pleated front are operated on in succession. Temporary tacks are replaced one by one with permanent tacks.
• 6 Other parts to be covered, like the back or its sections, may require machine sewing and the attachment of pull tabs that will allow the fabric to be stretched between frame slats and secured. Cotton batting is layered on as well, and the appropriate panel of fabric laid down, basted, stretched fully into place, and fixed with tacks. The outside is the last part to be padded and covered, starting at the arms. The open area is covered with a layer of burlap, an outside cotton padding, and finally the finishing fabric. Covering is fabric-stitched on top and tacked into place on the bottom, front, and back. The largest panel left open is the outside back. If the webbing has left any gaps between frame slats, these must be stuffed. Padding should be basted over the gaps along the whole outside back. The fabric panel for this section may be welted, or edged with a decorative strip made of stuffing cord covered in matching fabric. The covering is basted, then sewn at the top and tacked at the bottom as with the other parts.

Finishing

• 7 After the sofa is flipped and covered at the base with a cambric (dust cover), finishing touches are then applied. The sofa may be fitted with one of several choices of skirt. Arms may be supplied with welted panel covers. Cushions are made separately to cover the seat. These are constructed most often from a jacket of ticking, encasing two pads that in turn frame an inner core of foam. Each one is covered with finishing fabric panels supplied with a back zipper, so the case can be removed for dry cleaning.

Framing

• 1 First the frame is constructed from wood that has been found clear of any defects. The thickness of the wood should allow for the heavy tension webbing to follow. If the frame is not sufficiently strong, it will not bear the weight redistributed into it by the webbing whenever someone sits down. Arms, back, or back sections, seat, and legs are attached. The preferred method is with clean-cut, fitted double doweled glue joints reinforced with comer braces, glued and also screwed into place. Each major part of the sofa will have to have springs attached separately, and also be padded separately. Consequently, they are "framed out" with reinforcing slats, arranged around the seat section.

Webbing and springs

• 2 The foundation is then set for padding. Jute, a kind of burlap made in India, is used as webbing. Strips of this material are interwoven, stretched across the frame, and tacked down. Flax twine is then used to strap the springs onto the webbing. Two lines of twine are tacked into position and then tied around a spring back to front. Another pair of lines will run side to side on each row of springs after all the springs have been lashed into position individually. If heavy-gauge springs are used in the "front row," these are further tied down with a length of wire. This process is repeated for the back, with special attention to the springs at the base, which are treated like the front row of seat springs. If the back comes in sections (sometimes three for design purposes), then each part is separately tied off and the twine ends tacked onto the four-sided frame. The same is true for any sides and arms. Each part will be wrapped in its own sheet of burlap after being completely fitted with secured springs. The burlap is cut to size for each part, tacked into place initially, and then tightly lashed to the springs to minimize movement. This is to prevent the springs from wearing through the burlap over time.

Padding

• 3 Each part is separately padded as well, with layers of burlap and horsehair or chosen synthetic material. The padding is placed in a burlap envelope, arranged on the edge of the seat, pinned into place, and stitched down. As the stitching progresses, the pins can be removed one by one. This roll is then shaped according to design requirements and stitched with special needles and more twine. After this is secured yet still pliable, a layer of about 15 lb (6.81 kg) 
  
  of padding is distributed over the whole area of the seat, extending over the roll. The layer is basted into place with long, loose stitches and covered with lighter weight burlap. Tighter stitching divides the seat into two areas called the platform and the nose or front edge. This front part is reshaped with hand stitching. After the shaping is completed, a final, thicker layer of padding is added to fill in dips left by stitching in the burlap, and basted like the previous layer. A muslin sheet of covering is applied, stitched into the break between the platform and nose, tightened across the front edge and back across the platform; its edges are tacked into place. Anomalies in the padding are addressed before proceeding.
• 4 The arms are done next in the same basic fashion. Layers of padding and burlap are fixed in succession and topped with muslin. The arms also have a front edge of extra thick padding. Once the arms are properly shaped the back or back sections may be padded. If there is more than one part to the back, the center is padded first up until the second burlap layer. Then, the two flanking sections are padded up to that point, to match the center in size. The edge roll is formed around the top and back of the crest rail or uppermost part of the frame, or the corresponding area of each of the back parts, each of which must be kept parallel to the others. After inspecting and making any adjustment to the padding, the exposed wood parts can be stained and finished to taste or design specifications.

Fabric

• 5 Every piece and panel that will be fabric covered must be measured and recorded in a cutting list. The fabric is purchased in one piece or lot. The panels are then plotted out in chalk so they match wherever their seams will meet when finally applied. If any of the panels and pieces need to be sewn together before being attached to the padded frame, this is taken care of first. The seat is covered with panels for the platform and nose and hand-stitched into place along the break between them over a layer of cotton batting. The nose is then covered first to check if the pattern continues along the front properly. The covering is fitted over the back or platform end and secured. The arms are covered next after being prepped with their own layers of cotton batting. A fan-pleated arm is a classic look. The fabric is folded into place around the front roll, in a series of pleats that look like an opened fan when finished. A series of strategically placed cuts may be made, so the fabric clears all obstructions presented by the frame. The top, bottom, back, and pleated front are operated on in succession. Temporary tacks are replaced one by one with permanent tacks.
• 6 Other parts to be covered, like the back or its sections, may require machine sewing and the attachment of pull tabs that will allow the fabric to be stretched between frame slats and secured. Cotton batting is layered on as well, and the appropriate panel of fabric laid down, basted, stretched fully into place, and fixed with tacks. The outside is the last part to be padded and covered, starting at the arms. The open area is covered with a layer of burlap, an outside cotton padding, and finally the finishing fabric. Covering is fabric-stitched on top and tacked into place on the bottom, front, and back. The largest panel left open is the outside back. If the webbing has left any gaps between frame slats, these must be stuffed. Padding should be basted over the gaps along the whole outside back. The fabric panel for this section may be welted, or edged with a decorative strip made of stuffing cord covered in matching fabric. The covering is basted, then sewn at the top and tacked at the bottom as with the other parts.

Finishing

• 7 After the sofa is flipped and covered at the base with a cambric (dust cover), finishing touches are then applied. The sofa may be fitted with one of several choices of skirt. Arms may be supplied with welted panel covers. Cushions are made separately to cover the seat. These are constructed most often from a jacket of ticking, encasing two pads that in turn frame an inner core of foam. Each one is covered with finishing fabric panels supplied with a back zipper, so the case can be removed for dry cleaning.