Sanding is the main way to remove old varnish. If that doesn't work, there are paint removers and gels that you can apply, wait about 15 minutes, then scrape away. You'll still probably need to sand afterward, however.
The basic difference between varnish and polyurethane is that a varnish is a thicker layer than polyurethane. Both work as a sealant to a surface. The key to a successful...
Varnishing your painting is a good idea. The varnish will help protect your painting from dust, yellowing, and sun damage. It also adds a nice sheen that can help the...
Two coats of varnish are usually enough for an acrylic painting. Be sure to apply the varnish in thin coats, and wait for each coat to dry before applying another.
You'll create bubbles in the varnish that will harden onto the surface of your acrylic painting. With this in mind, it's never a good idea to shake your varnish.
Hydroquinone is a lightening cream that you get over-the-counter or prescription. It is available in concentrations up to 2% over-the-counter, but higher concentrations will require a prescription from your doctor.
You should try removing it with an acidic toilet bowl cleaner. Use a product that cleans lime, rust, hard water, calcium, etc. Make sure you cover all the rust surface...
