How do you clean antique wicker that has been painted and is brittle?

Try to use a little wood glue first for the pieces that are sticking up ,allow to dry,and use a Clear rustoleum spray sealer for wicker.

I usually use a staple gun on stray strands of cane after using glue. Use a small paint brush.As I put a decent primer on I spray water on first to dampen cane. This helps soak the paint into difficult tricky spots. Then paint with a good gloss paint. Perhaps 2 coats are needed depending on the cover. Consider spraying on the final coat as again the paint will reach the tricky spots.

Cheers

Kris from Australia

Spar urethane is a little different than polyurethane. It dries to a clear, more flexible finish, so it works well for wicker furniture that extends and flexes as people sit or lie on it. Spar urethane also works well to prevent cracking and splitting. Reapply this coating over the whole surface of the furniture piece every two years.

Marine varnish can be applied directly to unfinished bamboo or it can be used to enhance the water-sealing abilities of any paint. It will alter paint color slightly but this will not be noticeable if you varnish the entire item. Allow 12 hours for dry time when you're finished.

Clear lacquer can be put on either with a brush or from a spray container. Be certain to turn the chair and use firm but steady pressure on the lacquer can if you're using one.

Wicker should be hosed down every so often to keep it from going brittle.

The furniture you are showing is not true wicker. It is actually made of rolled paper, I had a set just like it. It does not take to excessive water, so a quick spray, and a brisk scrub with a long, soft bristle brush to clean it. (Similar to car wash brush). White glue to fasten down the broken bits, and a flexible paint finish, clear or colors, your choice, to seal it.