When it comes to woodworking, knowing the properties of a few common glues can help you choose the right adhesive for the job. For actually bonding wood to wood, standard yellow wood glue is hard to beat. For other shop tasks like fixturing, patterning, filling voids, repairs, and specialty operations, having a selection of other glues on hand is very useful.
Note: When working with glue (or any chemical), CAREFULLY READ the manufacturer’s directions and safety information. Some chemicals can cause direct and immediate harm, and some can do so slowly over time. Protect yourself accordingly!
Glue properties to consider:
What does it bond to
Working/open time
Cure time
Toxicity/safety
Color when cured
Clean up
Flexibility/creep
Water resistance
Gap filling
Yellow glue (aliphatic resin or polyvinyl acetate) is a shop standard. It has a proven track record of strength and durability, and it’s easy to use, inexpensive, readily available, non-toxic, easy to clean up, and fast drying. It is not gap-filling, so it works best on surfaces with good tight contact, and should be clamped for 30-60 minutes (in unstressed applications) or up to 24 hours (for stresses joints) while drying. Downsides include a short open time (5-10 minutes), non-reversibility, and susceptibility to creep (pieces may slip over time, meaning this glue is not suitable for veneer work). It is best for bonding wood and other porous materials, and not as good for joining dissimilar materials, such as stone or metal and wood.
Common brands: Titebond, Gorilla, Elmers
Bonds to: wood, paper, and other porous materials
Working/open time: ~5 minutes
Cure time: 30-60 minutes
Toxicity: low
Color: yellow/brown
Clean up: water
Flexibility/creep: yes
Water resistance: some
Gap filling: no
Polyurethane (PU) glues offer longer open time than PVA glues, high water resistance, and no creep. They need some moisture to cure properly, and require longer clamping times. Glue that’s squeezed out of a joint turns to a foam. These glues also are better than PVAs at bonding dissimilar materials. Downsides: bonds to skin, harder to clean up, more expensive and more toxic than PVA wood glue, longer cure time.
Common brand: Original Gorilla Glue
Bonds to: wood, stone, metal, ceramic, foam, glass
Working/open time: ~10 minutes
Cure time: 1-2 hours
Toxicity: Eye and skin irritant. Use appropriate PPE.
Color: tan
Clean up: While still wet, wipe with a dry rag or isopropyl alcohol. Once dry, it is best removed by mechanical means such as sanding, chiseling, scraping or picking
Flexibility/creep: no
Water resistance: high
Gap filling: no
Hide glue, which is made of hydrolyzed collagen and urea, is available either as a ready-to-use liquid or as pellets that need to be mixed with water. It has a much longer open time than yellow wood glue, and instead of swelling the pieces and making joints difficult to close, it acts as a lubricant, which can make tricky assemblies much easier. Most types of hide glue need to be heated up before application. It is very strong, but has low resistance to heat and water. This property makes it reversible, which is desirable for period furniture and instrument makers who want the option of disassembling an object without destroying it. Unlike yellow glue, it sticks to itself–meaning loose joints can be repaired by simply adding glue. It cleans up with water, and is basically transparent to finishes. Once opened or mixed, it has a limited shelf life.
Common brands: Old Brown Glue, Titebond, Brooklyn Tool & Craft
Bonds to: wood and other porous materials
Working/open time: 1 hour
Cure time: 24-48 hours
Toxicity: nontoxic
Color: brown
Clean up: water
Flexibility/creep: no
Water resistance: low
Gap filling: no
Epoxy ranges from the five-minute variety available at hardware stores to versatile formulations borrowed from the boat-building trade. It consists of a resin and a hardener that are mixed just before use. Epoxy is available with a range of open and cure times. Unlike most other glues, epoxy also can be used to fill gaps without significantly decreasing strength. It is best used for outdoor/marine applications, filling knot holes, and gluing/repairing gappy joints. Downsides include cost and toxicity.
Common brands: Loctite, JB Weld, Devcon, Gorilla. For more specialized applications, brands include West System and System Three.
There are too many varieties of epoxy to summarize here, so I will use JB Weld’s Clear Weld as a representative example:
Bonds to: wood, metal, plastics, tile, ceramic, glass
Working/open time: sets in 5 minutes
Cure time: 1 hour
Toxicity: Eye and skin irritant. May cause allergic reaction. Use in a well-ventilated area with appropriate PPE.
Color: clear
Clean up: solvents like lacquer thinner or acetone
Flexibility/creep: depends on application
Water resistance: yes
Gap filling: yes
Cyanoacrylate (CA) is extremely fast-acting glue, especially when used with an accelerator. It’s not a general-purpose glue when it comes to woodworking, but it’s ideal for repairing splits and other defects in wood. It is available in different viscosities for different uses. Downsides: superglue has a short shelf-life, it is non-reversible, it bonds to skin, and cured joints are fairly brittle. Ounce for ounce, it’s much more expensive than other types of glue, but a small bottle also goes a long way.
Common brands: Loctite, Gorilla, Krazy, Scotch
Bonds to: wood, stone, metal, plastic, glass, ceramic, paper
Working/open time: seconds
Cure time: 1 minute
Toxicity: Eye and skin irritant. Use appropriate PPE.
Color: Clear
Clean up: acetone or debonder
Flexibility/creep: no
Water resistance: moderate
Gap filling: no
Spray glues make it easy to apply a consistent coat of adhesive, but they are not strong enough for direct woodworking applications. Even so, they are useful to have around the shop for temporarily affixing patterns or making sanding blocks. There is a huge range of glues available from manufacturers like 3M, each suited to specific materials and use cases.
Common brands: 3M, Scotch, Gorilla
Bonds to: Foam, paper, metal, plastic, fabric, wood
Working/open time: 30 seconds-15 minutes
Cure time: instant upon contact
Toxicity: Flammable. Eye and skin irritant. Use in well ventilated area with appropriate PPE.
Color: variable
Clean up: acetone
Flexibility/creep: yes
Water resistance: variable
Gap filling: no
Hot glue is a thermoplastic bonding agent that's solid at room temperature but becomes a liquid when heated. When applied to a surface and allowed to cool, it solidifies and bonds materials together. Hot glue is available in high temp, low temp, and various colors. In the woodshop, this glue is best used for temporary fixturing or test assemblies. Not suitable for strong, permanant joinery.
Common brands: too many to mention
Bonds to: wood, paper, fabrics, foam, some plastics
Working/open time: a few seconds to a few minutes
Cure time: a few seconds to a few minutes
Toxicity: non-toxic when used correctly
Color: variable
Clean up: mechanical removal by scraping. Sometime heating or cooling the glue helps
Contact cement is a solvent-based adhesive that can bond to almost anything but is especially useful for nonporous materials that other glues don’t work well on, like leather, rubber, plastics, veneers, glass, and metal. It is typically applied separately to the surfaces to be joined and allowed to air dry for 15-20 minutes until tacky before the parts are pressed together. The adhesion is basically instant, so momentary pressure is needed rather than long-term clamping. The solid adhesive is made liquid enough to apply with the addition of solvents that release volatile organic compounds (VOCs), which are regulated by the U.S. Environmental Protection Agency because they are toxic and flammable. Use appropriate PPE and make sure your work area is well ventilated. Newer water-based contact cements are nontoxic and environmentally friendly.
Common brands: Weldwood, 3M Fastbond, Barge
Bonds to: leather, rubber, cork, paper, fabric, neoprene, plastics, laminates, metal, wood
Working/open time: 15-20 minutes
Cure time: near instant upon contact
Toxicity: Flammable. Eye and skin irritant. Use in well-ventilated area with appropriate PPE.
Color: variable
Clean up: see manufacturer's directions
While cyanoacrylate glue sticks to acrylic just fine, it has the unfortunate side effect of fogging and/or crazing clear plastic. For visually clear adhesion, solvent-based glues cause a chemical reaction that softens the acrylic surface and welds pieces together with a strong chemical bond. The fit between the parts must be very tight and gap-free for the solvent to wick into place. The solvents in the glue release volatile organic compounds (VOCs), which are regulated by the U.S. Environmental Protection Agency because they are toxic and flammable. Use appropriate PPE and make sure your work area is well ventilated. For more details, visit Acme Plastics’ guide to gluing acrylic. Note: there are other specialized glues for other types of plastic.
Common brands: TAP Acrylic Cement, Plastruct Plastic Weld, Weld-On*
*Weld-On 3 cures fastest and Weld-On 4 cures a little slower. Weld-On 16 is a thicker formulation for gaps up to 1/16”. Weld-On 40 is a 2-part mix a bit like epoxy that bonds better on thicker material.
Bonds to: acrylic
Working/open time: see manufacturer's directions
Cure time: a few seconds to a few minutes
Toxicity: Flammable. Eye and skin irritant. Use in well ventilated area with appropriate PPE.
Color: clear
Clean up: see manufacturer's directions