How Ultrasonic Cleaning Brass Can Restore Gleam

Those appreciating the gleam of brass – whether fireplace andirons & tools, chandeliers, escutcheons, or antique decorative brass hardware of any description – also appreciate the work that goes into restoring and maintaining the gleam of brass.  Chemical-based brass cleaners on the market usually require lots of time to apply and buff it off to reveal the shine.  This post describes how ultrasonic cleaning brass can help savvy collectors or sellers of brass products restore the gleam of antique brass. 

Why Ultrasonic Cleaning Brass Works so Well

The power of ultrasonic cavitation in an ultrasonic cleaner removes heat marks, soot deposits and other grime on fireplace implements that accumulates over the heating season. 

Similarly it removes tarnish and other surface deposits on brass door knockers, mail slots, latches, name plates, switch plates – in fact any decorative or functional product made of brass.

As suggested above, sonic cleaning also avoids the danger of damaging brass surfaces by using scrapers, steel wool and other abrasive methods to remove stubborn stains including years of built-up paint applied by prior owners.

Instead, simply immerse brass parts in an ultrasonic cleaning solution and let cavitation do the work. Unless the brass is severely discolored cleaning should take about 10-20 minutes. 

Cleaning Functional and Decorative Brass

Cavitation action in an ultrasonic cleaner is provided by generator-powered transducers excited to ultrasonic frequencies measured in kHz or thousands of cycles per second.  The process creates countless minute bubbles in the ultrasonic cleaning solution that implode violently on impact with surfaces being cleaned.  The process quickly and safely removes and carries away dirt, tarnishes and other deposits. 

The ultrasonic frequency determines the size of the bubbles.  A commonly used frequency is 37 kHz delivered by the Elmasonic Select series of cleaners available, and which should be ideal for cleaning most heavily tarnished brass products.

Some of the features of the Elma Select series ultrasonic cleaners include:

• a Sweep mode to provide more uniform distribution of cleaning energy throughout the bath
• a temperature control at 5⁰C increments from 30⁰ to 80⁰C
• a Degas mode to speed the preparation of fresh cleaning solutions, and
• a timer including an auto-start feature when the solution reaches the set temperature

These and other features are operated by a user-friendly control panel equipped with LEDs indicating actual and set temperature and time.  There is also an on-off key and an ultrasound start/stop key.

Selecting the right Ultrasonic Cleaner

Equipment selection for ultrasonic cleaning brass should start with ensuring the unit is large enough to accommodate the objects being cleaned.  If this is your first experience, visit our ultrasonic cleaner learning center for more information.

Disassembly, if feasible, is recommended because you are only cleaning the brass components. 

You need to think tank size, cleaning basket size and working depth, which is the distance between the bottom of the cleaning basket and the surface of the cleaning solution.  It is important that all parts be fully immersed in the solution.

Ultrasonic cleaners come in many sizes from less than a gallon to industrial units of 25 to more than 100 gallons.   Our example is the 2.5 gallon Elmasonic Select 100 with a stainless steel basket 10 x 7.9 x 3 in. deep.  If it turns out that you’re building a business of cleaning brass hardware you might want to consider larger units in order to process several orders at a time.

Selecting Ultrasonic Cleaning Solutions for Brass

How to Remove Paint from Brass Hardware

When you clean brass you must take into account what you re removing.  One of the most common challenges is removing years of built up paint from beautifully crafted hinges, door knobs, escutcheons and similar fittings. 

Often but not always this can be accomplished with or without the use of an ultrasonic cleaner. 

For example, a wide range of paints, coatings and contaminants can be removed using non-flammable formulations diluted with water for use in benchtop or floor-mounted industrial ultrasonic cleaners offered by Tovatech.  

And in many instances these cleaners also work in a simple wash tank or a ultrasonic cleaner without activating the ultrasound.

Because these formulations work as emulsions they do not dissolve coatings but loosen them for fast rinsing.  This means that the formulations can be filtered and reused time and time again.

How to Remove Tarnishes and Other Contaminants from Brass

The correct cleaning solution chemistry is as important to the job as the equipment itself when it comes to removing other contaminants from brass using an ultrasonic cleaner.

We recommend Elma tec clean A2, a biodegradable liquid ammoniated concentrate ideal for cleaning and brightening brass, copper, bronze and similar non-ferrous metals.

Ammonia is the brightener and it will give off ammonia fumes so we recommend placing the equipment below an outside exhaust vent and following the recommendations on the product’s material safety data sheet.

Preliminary Steps:

• Add water half way to the cleaning tank fill line
• Add the correct amount of Elma tec clean A2 for a full tank and add more water to the fill line
• Turn on the unit and activate the Degas mode.  This both mixes the solution and removes trapped air.  Degassing must be done each time you prepare a fresh cleaning solution.

Cleaning Steps:

These will vary depending on the condition of the brass implements being cleaned and the ultrasonic cleaner you use.  As you gain experience you’ll develop your own procedures.  For the Select 100:

• Turn on the ultrasonic cleaner and set the temperature to 60⁰C.  The LED will indicate the actual and set temperature.
• Place brass components, disassembled if possible, in the basket.  Try to avoid contact between parts.  Lower the basket into the solution and place the lid on the tank.
• Activate the Sweep mode, set the timer to 20 minutes if the brass is extremely discolored.  The unit will start when it reaches the set temperature or you can start it immediately.
• At the end of the cycle remove the basket and place it on the inverted lid that serves as a drip tray.  Inspect the parts.  If satisfied rinse them thoroughly and allow to dry.

Extended cleaning time may indicate it is time to replace the solution.  Drain the tank and dispose of the solution according to local regulations.  Rinse the tank with clean water following the instruction manual.  You are now ready to prepare a fresh batch.

Contact the ultrasonic cleaning professionals at Tovatech to discuss equipment and cleaning solution chemistries that meet your needs for cleaning functional or decorative brass.