Cleaned Antique Door Hardware

Craftsmanship and artistry combine in designing and casting door hinges, handles, escutcheons, back plates, rosettes and similar decorative hardware characteristic of Victorian era or other 19^th and early 20^th century residences.  Folks that appreciate such quality are often challenged because the beauty of the design is hidden under layers of paint or otherwise obscured by years of dirt build-up.  Restoration, either professionally or by the do-it-yourselfer, can be facilitated by using specialized cleaning emulsions and the power of ultrasonic cavitation.

 Cavitation described

Cavitation is the implosion of minute bubbles coming in contact with items immersed in a sonic cleaner solution.  They are created by ultrasonic transducers operating at a frequency such as 37 kHz (37,000 cycles per second) in an ultrasonic cleaner exemplified by the Elmasonic E series available from Tovatech.  The bubbles access all surfaces of hardware immersed in the bath to safely remove paint, grease and other contaminants.  This restores the product to a like-new condition faster and much more thoroughly than by using harsh chemicals and potentially damaging steel wool or wire brushes. 

Selecting a cleaning solution

You might have to do some experimenting when it comes to removing paint from brass, copper and bronze hardware simply because paint formulations have changed over the years.  To start out we suggest trying CLN-STR7-5.  This is a semi-aqueous, micro-emulsion solution that can be used two ways.  It can be used as a pre-wash chemical to safely remove oil and water based paints by lifting them off the metal surfaces.  Or you can speed delaminating by using it full strength in an ultrasonic cleaner operating at about 70˚C.  Unlike most ultrasonic cleaning solutions this product can be reused by filtering it to remove paint debris. 

Other products that strip paint and varnish off of metal surfaces are CLN-LR201 (with ammonia) and CLN-LR110 (ammonia free).  These are a concentrates that should be diluted 1:7 with water before use. The ammoniated product is much stronger than the non-ammoniated but produces an odor especially at elevated temperatures and must be used with proper ventilation.  Cleaning solution temperatures should be set at <40˚C for ammoniated and 50˚C for non-ammoniated.

If the hardware is not plastered over with paint (lucky you) we suggest using biodegradable CLN-LR 211 diluted 1:8 with water.

Using the ultrasonic cleaner

You’ll develop a routine but here are the general steps.  Add the cleaning solution to the ultrasonic cleaner fill line and, using the intuitive microprocessor control panel, set the temperature to 40˚C and the timer to 40 minutes.  This degassing step drives off cavitation-inhibiting air and must be taken every time a new solution is prepared. 

When air bubbles stop floating to the surface you’re ready to begin.

• Carefully place the parts in the cleaning basket so they do not come in contact with each other. A fine mesh immersion basket safely holds screws and other small parts.
• Lower the basket into the cleaning solution then start the cleaning cycle using either the manual start or temperature-controlled auto start
• As paint residue rises to the surface skim it off and set it aside for future disposal
• Examine the hardware and continue ultrasonic cleaning until all paint residues are removed 

If you are satisfied with the finish, rinse the hardware thoroughly in water and dry it. In such cases you may not have to repeat the process to remove tarnish and other dirt.

The process is the same for unpainted hardware but using CLN-LR 211 cleaning solution diluted 1:8 with water.

In summary, an ultrasonic cleaner can quickly pay for itself if you are involved in restoring antique brass, bronze and copper hardware.  Contact the ultrasonic cleaning professionals at Tovatech for top-notch advice on developing a business or hobby restoring the quality construction of yesteryear.