It's sometimes possible to strip old paint or varnish from wicker, though not always as successfully or as easily as with wood.
Begin by brushing on a thick coat of paint-and-varnish remover, working it deeply between the strands (Image 1). To keep the surface wet, spray on paint-and-varnish remover from an aerosol can. When the finish softens, use a small, stiff brush to remove it (Image 2). Brass or natural bristles are suitable, but avoid using wire brushes, which can damage the wicker strands.
Cut the bristles from a paintbrush, leaving about 1/2" of stiff bristles, and use it to scrub off remaining loosened paint with mineral spirits.
Wicker is less likely than wood to be damaged by water. In fact, if the wicker is unfinished, an occasional misting is sometimes recommended to keep the material flexible. When stripping wicker outdoors, you can use a forceful stream of water from a garden hose to blast away loosened paint.
Old layers of paint that have built up over the years can be removed from metal patio furniture using methods similar to those employed with wicker.
Brush on a thick coat of paint-and-varnish remover, and allow it to stand for about 20 minutes. Use a coarse rag or bristle brush to remove loosened paint (Image 1). Avoid steel wool, which may scratch softer metals. If necessary, apply a second coat of remover. Use a bristle brush or synthetic pad to remove the last of the softened paint, then wipe the piece with a rag dipped in mineral spirits (Image 2).
Once you've stripped the piece to bare metal, avoid letting it come in contact with water, which can cause rust to form almost immediately. If rust spots appear, sand them off before repainting.
Once you've stripped a piece, you may notice a few places you've missed--such as in carvings or around detail work. It's best to remove these remnants of finish while it's still soft from the stripper. Use an old toothbrush or cotton swabs dipped in mineral spirits to remove finish in difficult areas (Image 1) . Follow up by wiping with a soft cloth. Leaving small amounts of the old finish deep in the crevices and carvings can help preserve an antique look.
Unused portions of stripper may be saved for future projects as long as the container is tightly sealed. Waste stripper, paint sludge, old brushes and used steel wool may be placed in a sealed container, then disposed of. Call your local sanitation department to find out how and where to dispose of the waste: community regulations on the disposal of toxic materials vary widely.
As you clean up, note that chemical-soaked rags can spontaneously combust and cause a fire. To dispose of them safely, place them in a container, fill it with water (Image 2) and seal it. Dispose of the sealed container with household garbage. Leave soiled drop-cloths and newspapers outside to dry, making sure to keep them away from pets or children, before throwing them away. Or soak drop-cloths and newspapers with water and throw them away.