To strip varnish safely, choose a stripper suited to the piece, work with good ventilation, gloves and eye protection, and scrape gently with the grain. Test the finish and check for lead paint before you start. The steps below cover chemical stripping, with notes on mechanical options for flat surfaces.
Test the finish and check for lead first
Test the finish on a hidden spot. Denatured alcohol softens shellac, and lacquer thinner softens lacquer. Those finishes often come off with a solvent, which is gentler than a full stripper. If neither solvent works, the finish is most likely varnish or polyurethane.
Painted pieces made before 1978 may contain lead. Test before you scrape, sand or heat the surface. Heat guns can also vaporize lead, and EPA lead-safe practices restrict heat guns on lead paint, so avoid them unless you have confirmed the paint is lead-free.
Choose the right stripper
Stripper types differ in risk and speed:
- Methylene chloride strippers are fast, but they are hazardous. Federal rules restricted them for consumer use in 2019, and a 2024 rule limits most remaining uses. Avoid them.
- Benzyl alcohol strippers, such as Citristrip, are lower in toxicity but slow. They can take from about 30 minutes to 24 hours to work.
- NMP strippers carry health concerns, and NMP is a reproductive toxicant. Rules vary by place, so read the label and check local guidance.
- Caustic (lye) strippers darken wood, raise the grain and dissolve hide glue. Avoid them on antiques and veneer.
Citrus or “natural” doesn’t mean non-toxic. Use gloves, goggles and ventilation with any stripper.
Shellac and lacquer: try solvents first
Shellac and lacquer often come off with denatured alcohol or lacquer thinner. How to remove shellac from antique furniture walks through the alcohol method. Solvents are usually gentler on the wood than a full stripper. Apply them lightly and work in small areas. This is also the first step for many rimu pieces, where reamalgamating the shellac can save the original finish.
Step by step: apply, wait, scrape, detail
- Ventilate and gear up. Work outdoors or with strong cross-ventilation. Wear chemical-resistant gloves, goggles and long sleeves.
- Apply a thick coat. Brush the stripper on in one direction. Don’t brush back and forth, because that breaks the surface film and lets the solvent evaporate faster.
- Cover slow strippers. Plastic film over the surface helps keep the stripper from drying out.
- Wait. Give it the time the label says. The finish should bubble, wrinkle or soften.
- Scrape. Use a plastic scraper, moving with the grain. Metal scrapers can gouge soft wood.
- Detail. Use a nylon or brass brush, a sharpened dowel, a toothpick or string for grooves and carvings.
- Repeat rather than gouge. Thick or multiple layers of finish may need a second application. Repeating is safer than digging harder.
- Clean. Wipe with the solvent the label recommends, usually mineral spirits or water. Use 0000 steel wool or a synthetic pad for stubborn residue.
- Dry. If you rinsed with water, let the wood dry for at least 24 hours before sanding.
Stripper residue left on the wood can stop a new finish from curing. Clean it off thoroughly.
Protect the wood and yourself
Heat guns can scorch wood, crack glass and soften the glue under veneer, which can buckle it. Don’t use one on veneered surfaces.
Don’t assume your protection covers every stripper. Some strippers need a specific respirator or glove type. Check the label for the required gear. Stripper solvents are flammable, so keep flames and sparks away.
Dip stripping in a caustic tank is risky for antiques because it can loosen glue joints and veneer. The antique furniture restoration guide explains gentler options.
Disposing of stripper waste
Stripper sludge and used rags can count as hazardous waste. Don’t put them straight in the trash. Check your local rules for disposal, and store used rags safely. Oil-soaked rags can catch fire on their own, so dry them flat outdoors or store them in water in a sealed metal can.
Mechanical alternatives for flat surfaces
On large, flat panels, a sharp card scraper can remove varnish quickly without chemicals, with little dust. Sanding is another option, but varnish clogs paper fast. Start around 150 grit and move to 220, and watch for sanding through thin veneer. Can I just sand varnished wood? covers the sanding route in more detail.
For carved or detailed pieces, stick with a stripper. Sanding blurs detail, and scraping can mark carvings.
For cleaning steps before you strip, see how to clean old wood furniture before refinishing.