How to burnish with steel media, according to Vibra FinishOctober 9, 2019 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.
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Vibra Finish provides many finishing services for metal parts. An essential service that the company offers is burnishing – particularly with steel media, a common technique. Burnishing is a polishing method that smooths the textures of rough surfaces to make them shinier, due to sliding contact with other objects. With close to 50 years of finishing experience, Vibra Finish can offer valuable advice to help customers get the most from the burnishing process.
Vibratory or barrel tumbler
According to the Vibra Finish team, there are two common types of tumblers with which one can perform burnishing with steel media: a vibratory finishing machine or a barrel tumbler. Each machine uses different settings and methods.
A vibratory tumbler needs to be set at or near its maximum. Then the user must fill the tub or bowl from 55 to 75 per cent with steel media and the parts being burnished, with a volume ratio of three to one in favour of the steel media. One such recipe used at Vibra Finish would be the mixture of large and small steel media. Large steel media, often 3/16 of an inch, increases action and should take up between 50 and 70 per cent of the total. Smaller steel media is about 1/8 of an inch.
Next, the user should pump a water and compound mixture into the tub or bowl, ½ a gallon per minute at a three-to-five per cent dilution rate. Vibra Finishes custom liquid burnishing compounds work quite effectively in this application. Change compound and water every four hours during the operation.
A barrel tumbler achieves best results when it is half full of parts and media. The user should put in the same volume ratio of media to parts as for a vibratory tumbler. Then the barrel should be filled with sufficient water to cover the whole load by one or two inches. Add burnishing compound diluted at three to five per cent.
The barrel should be rinsed out after every operation, and fresh water and compound each time. Processing can take anywhere from one to 20 hours.
To learn more, contact Vibra Finish.