Woodworking Glue

Joints should be made to fit well, rather than relying on the gap-filling properties of adhesive. Make sure the gluing surfaces are clean and free from grease. Some woods, such as teak and rosewood, are best glued as soon after cutting as possible, before their natural resins form a surface film that prevents glue being absorbed properly.

Epoxy For Wood Joints

atmosphere, apply glue in a thin, even layer to both halves of a joint. Take care to coat the surfaces of a mortise, since most of the glue applied to the tenon is wiped off as the joint is assembled.

Don't rush when gluing up, but work as quickly as practicable, in order to assemble joints before the wood begins to swell and the glue starts to jell. For a large or complicated assembly, use a two-part glue that is applied separately to joining surfaces. Place glued components in cramps, and wipe off excess adhesive with a damp cloth.

PVA adhesive

Commonly known as white glue, polyvinyl-acetate (PVA) glue is a popular and convenient adhesive for joint-making. A ready-mixed emulsion supplied in plastic bottles, PVA sets by evaporation. It is a nontoxic glue that is easy to apply and is almost clear when set.

General-purpose PVA glue is only suitable for interior work. Although it forms a strong bond, the glue line remains relatively flexible and may creep (allow movement) when a joint is subjected to a prolonged heavy load. It does not sand well, as friction causes the glue to soften and clog abrasive paper.

Aliphatic-resin PVA glue is similar to the general-purpose version, but has improved moisture resistance and is less flexible.

Chemical-bonding, cross-linking' PVA glue is even more water-resistant, and forms an exceptionally strong bond.

Urea- and resorcinol-resin adhesives

Urea-formaldehyde-resin glue is a two-part adhesive that sets by chemical reaction. It is an excellent water-resistant adhesive that dries with a hard glue line. The resin and hardener are usually supplied pre-mixed as dry powders that are activated when mixed with water; the mixture remains workable for 20 minutes.

With some urea glues, the resin is packaged with a separate liquid hardener. The resin is applied to one half of the joint, the hardener to the other, and the glue only begins to set when the joint is assembled.

For even greater strength coupled with superior water-resistance, choose a resorcinol-formaldehyde glue, a two-part adhesive that is mixed prior to application. Either a liquid resin is supplied with a powdered hardener; or both constituents are in liquid form. Resorcinol resin dries to a reddish-brown glue line.

When working with uncured glue that contains formaldehyde, always work in a well-ventilated workshop, and wear a face mask, gloves and eye protectors.

Hide glue

Traditional hide glue has been largely superseded by synthetic-resin adhesives, but still has advantages for furniture restoration and veneering. It is a strong-smelling, but non-toxic, glue made from animal skins and bone. It forms a strong bond that can be reversed by the application of heat and moisture. Hide glue is usually supplied in granular form for dissolving in water heated in a jacketed glue pot. When rendered to a smooth, runny consistency, the glue is applied hot to both joining surfaces It sets, by cooling and evaporation, in about two hours.

Wood Working 101

Wood Working 101

Have you ever wanted to begin woodworking at home? Woodworking can be a fun, yet dangerous experience if not performed properly. In The Art of Woodworking Beginners Guide, we will show you how to choose everything from saws to hand tools and how to use them properly to avoid ending up in the ER.

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