Burnishing is a finishing process used in lapidary arts and other crafts to create a smooth, shiny surface on materials like metal, wood, leather, and stone. The burnishing process involves rubbing the surface with a hard, rounded tool to compress and polish the material. There are two main types of burnishing – dry burnishing and wet burnishing. The choice between dry or wet burnishing depends on several factors including the material, the desired finish, and efficiency. This article will examine the difference between dry and wet burnishing methods, compare their advantages and limitations, and provide guidance on selecting the appropriate technique.
The main question this article seeks to address is: Is burnish fundamentally a dry or wet process, and when should each method be used in lapidary work? Through a detailed comparison of dry and wet burnishing processes, tools, and applications, this article will demonstrate that both techniques have their merits and limitations. The most suitable burnishing method depends greatly on the material and project goals.
Key Takeaways – Choosing Dry vs Wet Burnishing
- Dry burnishing – Quick, simple, inexpensive. Best for hard materials. Risk of overheating and damage.
- Wet burnishing – Slower process, costs more. Allows soft and fragile materials. Superior finish.
- Consider material properties, surface finish goals, time, cost, environment.
- Hard, durable materials – Dry burnishing usually preferred.
- Soft, delicate materials – Wet burnishing strongly advised.
- Basic sheen – Dry burnishing likely sufficient.
- Mirror gloss – Wet burnishing recommended.
- Fragile surface – Avoid dry burnishing risks with lubricants.
- On tight deadline – Dry burnishing faster result.
- Budget conscious – Stick to dry burnishing.
- Alternative methods – Buffing, sanding, polishing, electrolytic.
Process and Tools
- Burnishing tools for dry burnishing include hand-held stones, ring burnishers, and power tools with shaped burnishing bits.
- The tools are rubbed over the work surface using consistent light pressure and strokes.
- No lubricating oils, waxes or water is used in dry burnishing.
- Relatively quick and simple process.
- Does not require additional consumables like lubricants.
- Suitable for materials like metal and wood that can withstand friction heat without damage.
- Gives a bright shine and smooth finish.
- Can generate unwanted heat through friction.
- Higher risk of surface damage on soft materials.
- Tool requires frequent re-polishing to maintain smoothness.
- Limited applications compared to wet burnishing.
- Metals like silver, steel, and brass.
- Hard woods like ebony, rosewood, and hard maple.
- Minerals like quartz, agate, and jasper.
Wet burnishing, as the name suggests, relies on lubricants like oil, wax or water to reduce friction during the burnishing process.
Process and Tools
- Lubricants like mineral oil, beeswax, diamond compounds or water are applied to the surface and tools.
- Burnishing tools glide smoothly with the lubricant to compress and polish the surface.
- Hand tools or rotating brushes/mops are used to burnish and re-apply lubricant.
- Allows burnishing of soft or fragile materials like leather and turquoise.
- Produces an exceptionally smooth, glossy finish.
- Lubricant prevents heat damage and tool wear.
- Can be easily automated for production work.
- Requires consumable lubricants.
- More preparation time needed.
- Can be messy if liquids are used.
- Environmental issues with chemicals/oils.
- Leather, plastic, soft wood
- Turquoise, opal, pearl and other soft minerals
- Ceramics, glass, acrylics
Comparison of Dry and Wet Burnishing
|No lubricants used
|Lubricants applied to surface and tools
|Exceptionally glossy, mirror-like
|Slower process with lubricant application
|No consumables needed
|Rapid wear without lubricants
|Greatly reduced with lubricants
|Friction can generate heat
|Lubricants prevent heat damage
|Best for hard, durable materials
|Allows burnishing of soft, fragile materials
|No chemical waste
|Oil/chemical disposal may be needed
In summary, dry burnishing is faster and cheaper but riskier on soft materials, while wet burnishing takes more time and resources but allows a wider range of materials and achieves a superior finish.
Factors in Choosing a Burnishing Method
The choice between dry or wet burnishing for a project depends on several factors:
- Material properties – Hard vs soft, fragile vs durable
- Surface finish goals – High gloss vs basic sheen
- Time considerations – Tight deadline vs ability to take time
- Cost constraints – Tight budget vs ability to invest in lubricants
- Environmental concerns – Reduce chemical waste vs premium finish
- Availability of lubricants/tools – Existing workshop supplies
This decision matrix can help select the suitable method:
|Hard, durable material
|Soft, fragile material
|Basic sheen finish
|Mirror gloss finish
|On tight deadline
|With budget constraints
|Environment a concern
While burnishing is great for achieving a polished, reflective finish, there are other options as well:
- Polishing – Uses abrasives like rouge/tripoli to abrade and gradually refine the surface.
- Buffing – Softer abrasive wheels are used to create a sheen.
- Sanding – Uses sandpaper/abrasives to smooth and prepare for polishing.
- Electrolytic polishing – Uses electrochemical reactions to remove microlayers of metal.
Polishing and sanding are more aggressive material removal processes compared to the surface compression of burnishing. Buffing can achieve similar results to burnishing but requires softer wheels. Each method has its own advantages and best applications.
Recent innovations that can advance burnishing techniques include:
- New tool materials like nanocrystalline diamond for longer-lasting burnishers.
- Hybrid lubricants that reduce waste.
- Automated machines for consistent results and quality control.
- Software to model and optimize burnishing parameters.
- Research on ultrasonic and magnetic field-assisted burnishing.
These technologies can help improve productivity, sustainability, and precision in burnishing applications. It may expand burnishing into rapid prototyping and high-volume production.
Challenges and Limitations
Some key challenges with burnishing:
- Achieving consistency across large surfaces.
- Preventing edge rounding/material removal.
- Surface cracks or tears on fragile materials.
- Finding the optimal combination of pressure, lubricant, strokes.
- Tool maintenance and reshaping.
- Safety issues from friction, heat, chemicals.
Understanding these limitations helps manage expectations and prevent failures. With proper technique and an understanding of material properties, high quality burnishing results are achievable.
In conclusion, burnishing for lapidary work can be broadly categorized into dry burnishing or wet burnishing methods. While dry burnishing is quicker and simpler, wet burnishing allows more versatility and superior finishes. The ideal technique depends on the material, project goals, time, budget, and environment. Both methods have a role to play and often the choice is not black and white. Mastering the nuances of both dry and wet burnishing, as well as alternative options like buffing and sanding, gives lapidary artists the full set of tools to create stunning polished finishes.
FAQs about burnishing
What is the difference between burnishing and polishing?
Polishing is more aggressive, using abrasives to remove material and create a shine. Burnishing compresses the surface instead of removing material. Burnishing gives a smoother, brighter finish than polishing.
Can you achieve both wet burnish and dry burnish on the same surface?
Yes, it is possible to do dry burnishing first to achieve an initial smoothness and then follow up with wet burnishing to get an exceptionally glossy finish. The dry burnishing provides the foundation that wet burnishing enhances.
What are the best materials to use for wet burnish and dry burnish?
Hard stones, metals, and woods are best for dry burnishing. Leather, plastic, soft stone, and delicate materials are better suited for wet burnishing. Very fragile surfaces may be difficult to burnish without damage.
How often should you burnish a surface?
For jewelry and small decorative items, burnishing once during finishing is typically sufficient. For tools and functional items, occasional re-burnishing helps maintain the protective polished layer from wear.
What are the common mistakes to avoid when burnishing?
Applying too much pressure, using a lubricant not suited for the material, inadequate cleaning before burnishing, using worn tools, and burnishing across the grain instead of along it. Take time to prepare the piece and use proper technique.