How to Fill a Cracked Brass Antique Door Knob

For sheer elegance and style, nothing can beat the look of an antique door knob. Many older houses have antique brass door knobs that are still functional, but might need a little TLC. Ornately cast brass door knobs were very popular in the late 1800s and into the early 21st century. Countless designs in a variety of sizes make repairing your antique brass doorknob a very viable option.


  • Salt
  • Vinegar
  • Dish Scrubber
  • Brass or Silver Solder
  • White paste Flux
  • Butane Torch Or Propane Torch
  • Epoxy
  • Jeweler's rouge
  • Brass paint
  • Hammer or dowel
  • Towels or rags

Step 1. Preparation: Cleaning Your Antique Doorknob

Brass is a relatively soft metal and can develop hairline cracks. It is possible to fix these and continue to use your antique doorknob. The first step is to remove the doorknob and clean it thoroughly. A simple non-toxic way to restore the luster and beauty is to clean your doorknob in a mixture of salt and vinegar. Mix salt and vinegar together to form a paste and gently scrub with a rag and dish scrubber. Use a clean rag to wipe away any residue. Cleaning your antique doorknob will allow your repairs to bond to the surface.

Step 2. Repairing Your Doorknob

Hairline cracks in brass can sometimes be filled with a clear epoxy. However, you want to be careful not to epoxy the door handle to the stem in case you ever need to remove it. Mix the epoxy and apply it with a small syringe. Immediately wipe up any excess. It's best to test this in an inconspicuous place first and make sure the epoxy will not stain the brass.

Step 3. Soldering Brass

For a more solid repair you can solder the brass together. Using white brass flux, heat the brass till the flux melts and fills the joint. Use a white flux to chemically clean the areas. The brass and solder will get fairly hot and can cause the brass to discolor. Test first in an inconspicuous area for possibility of discoloration before proceeding over general area. The second step is to reheat and wick up any excess solder. When it is cool you can polish with a jeweler's rouge. Touch up with brass paint if needed.

Step 4. Repairing Dents and Dings

Sometimes antique doorknobs can get damaged leaving dents and dings. It might be possible to repair these by removing the handle and gently pounding out the dent from the inside using a hammer and small dowel. Remove the door handle from the square stem and place on a hard surface. Pad the area with multiple towels or rags. For working on detailed areas, use a nail set. If you have a hole in your antique brass doorknob you can fill it from the inside with a two-part epoxy paste and paint to match.

Restoring your antique doorknobs can give your home the elegance and feel of a Victorian masterpiece. Clean and protect your antique brass door knobs, and they will help open a lot of doors for you in years to come.