Epoxy Glue Mix Volumes

Epoxy Adhesive: Mixing Volumes (Resin + Hardener)

Epoxy is a two−component adhesive. Component A is the resin and component B is the hardener, or catalyst. Nothing happens until you mix them, and then they react into a rigid polymer that shrugs off most chemicals. The ratio is usually A:B = 1:1 or A:B = 2:1 by volume, which depends on the product (Loctite, Araldite and Brascoplas are common Brazilian brands). For a total of V mL at 1:1, take V/2 of each; at 2:1, take 2V/3 of A and V/3 of B.

Mix on a clean, disposable surface such as cardboard or a plastic plate, stirring with a wooden stick for at least 1 minute until the color goes uniform. Working time, the pot life, runs about 5–20 minutes, so don't mix more than you can lay down in that window. It gels in 30–60 minutes and reaches full mechanical cure at 24 hours. Once cured, density sits around 1.1 g/cm³.

Applications

It bonds wood, metal, glass, ceramics, stone and rigid plastics, fills cracks, encapsulates electronics, and shows up in jewelry and resin art as well as structural repairs on furniture and boats. Cured, it holds up well against both chemicals and water.

FAQ

What happens if I get the ratio wrong? Add too much hardener and it cures faster but turns brittle. Add too much resin and it stays sticky, sometimes never curing at all. Keep to the manufacturer's ratio within ± 5%.

Can I speed up cure with heat? You can. A hair dryer or a warm room at 30–40 °C roughly halves the cure time. Keep open flame away, though, since uncured epoxy is flammable.

Can I sand or paint the cured epoxy? After 24 hours, yes. It sands, drills and takes paint, whether acrylic or enamel. Put on a dust mask first, because epoxy dust is an irritant.