Balsa

Overview

Balsa (Ochroma pyramidale) is the lightest and softest commercial wood: white to off-white or tan sapwood, with a density of only about 150 kg/m3 (8 to 14 lb per cubic foot). Botanically it is a hardwood. People use it for models, cores, floats and carving, not for furniture.

Pros

• Extremely light, with excellent sound, heat and vibration insulating properties, per Wood Database.
• Very easy to work, with virtually no dulling of cutters.
• Plantation-grown, and not listed in CITES or the Red List.
• Stains and finishes acceptably, and glues readily.
• Cheap in bulk; hobby strips are dear per volume.

Cons

• Dents under a fingernail, perishable and unsuited to structure or outdoor use; the sapwood is rated perishable and attracts insects.
• Fuzzy surfaces are common unless cutters are very sharp.
• Holds nails poorly; glue is the preferred joint.
• Density varies widely tree to tree, so strength does too.
• Reported to cause skin irritation.

Variants and subspecies

• Ochroma pyramidale: the single commercial species.
• Grades: high-quality balsa has very low density, and dealers sort accordingly.
• Sheets and cores: end-grain balsa is used as core stock in sandwich laminations.
• Look-alike: Basswood is a soft, easy North American carving wood, though heavier.

Working and finishing

Cut with a fresh, very sharp blade; dull cutters crush rather than slice. Join with glue, not nails. Seal the surface with a sanding sealer before painting or varnishing, because it soaks up finish. Sand lightly.

Staining and finishing colour

Stains and finishes well but absorbs finish heavily; seal first. Natural colour is white to tan with occasional pink or yellow hue.

Sustainability and handling

CITES and IUCN: not listed in the CITES Appendices or on the IUCN Red List (Wood Database; APHIS CITES Timber Manual, checked 2026-09-30). Wood Database notes plantation-grown balsa. FSC availability is not verified here. The US Lacey Act makes it unlawful to trade wood taken or exported in breach of the source country's laws (fws.gov/law/lacey-act), so buy from dealers who can name the country and species. If a piece will be exported to or sold in the EU, Regulation (EU) 2023/1115 (the EUDR) requires due-diligence evidence that wood products are deforestation-free and legally produced; check its current application date with your buyer.

Ethical call: low concern. Health: reported to cause skin irritation. The US National Cancer Institute reports strong, consistent associations between wood-dust exposure and cancers of the nasal cavity and sinuses, so use extraction and a respirator when sanding.

Popular projects

Model aircraft and boats, surfboard and paddleboard cores, sandwich-laminate cores, buoys and rafts, fishing lures, packing cases and carved pieces.

Buying notes

Hobby shops sell strips and sheets; larger boards are hard to find at hardwood dealers, per Wood Database. At two thicknesses, one dealer's strips equal about $28 to $95 per board foot (September 2026). Pick by weight: lighter pieces are the high-quality, low-density stock.