Post 577 by Gautam Shah


Chocolate dipped ice cream on wafer cone (Flip 2019)













Body Creams and Lotions > Wikipedia image by Gryffindor





Ancient manner of Butter making in Canada > Wikipedia image





Screen printing Binders are Acrylic emulsions > Wikipedia image



Plastic Paint







Post 576by Gautam Shah


















Esgaroth or Lake Town – a fictitious neighbourhood community that appears in novel The Hobbit (1937) by J R R Tolkien > Wikipedia image work source Angrenost.cz by Neral (Matej Cadil)





































Post 575by Gautam Shah


Masking is an overlay on an opening such as a window, door or gap. The overlay could be an additional system, opportunistic exploitation of the surroundings, or an arrangement for doctoring the perception. There is an attempt to change the quality of view, such as increasing or decreasing the clarity of view; add directional emphasis, such as horizontal, vertical or some other direction and alter the proportion and scale of the view; to divide the view into smaller geometric or floral sections and to camouflage or conceal the opening itself, the shape, location or purpose.

Framed View

Framed View through Opening > Pixabay image

Masking of openings happens over the gap portion, but Framing of openings occurs on surrounding portions of the gap. Masking and framing often serve similar purposes, which are of camouflaging the shape of the opening. Shape modulation also affects the size perception. Openings gain a tectonic meaning in consonance with the site, the environment, people and other building elements. Primary framing takes place, on how an opening is composed within a barrier system.


Door Framing II nd Floor Balcony at Palace of Raio > Baroque era Residence at Braga, Portugal > Wikipedia image by Sara silva

Technologically shutters of doors and windows, pivoted or hinged, have been square edged. This in turn forced the shape of openings to be square edged. Doors, windows and gaps, till about pre-gothic period were overawed by the powerful geometry of the squared edges. The only option was to taper the faces of sides and bottom sill. Lintel bottom remained flat, being structurally inviolable. Occasionally stepped or layered lintels were used.

Gothic Tracery

Gothic window tracery St Mary Church, Snettisham, Norfolk, England > Flickr image by Spencer Means

Square lintels or the round arch-vault, was a necessity for massive Romanesque structures. Gothic period, however, saw some degree of liberation from the square cornered rounded arched openings, mainly due to the thinner walls and use of pointed arch. But this advent was accompanied by shutter-less fixed glass openings. The shuttered opening like doors, however continued to have squared lintel heads, framing and shutters.


Serrated door Framing Amiens Cathedral > Wikipedia image by Mattana

The square edge, for the first time was consciously and successfully dissolved during the Rococo period. The Rococo period had two important facets: Motifs over interior face of openings in the form of painted stucco work, and architectonic elements and sculptures over the exterior face of the opening. This integration of elements over the openings, however, never transgressed the square edges of the frame or shutter. It had to wait till Art Deco and Art Nouveau periods when few adventuresome breached the omnipresent straight lines of the openings.


Masking and Framing of Door at Art Nouveau Building from architect Jules Lavirotte Paris France Sculptures by Jean Francois Larrive 1875-1928 > Wikipedia image by Pline

The framing transformations first occurred in the print media, artwork and jewellery items like photo-pendants. Photo and painting frames continued with the squared edges on the inner face. These were of Two types: Tapered inward or outward. Over the period all forms of frames drew inspiration from each other.

1 Frames_France

Photo Frame 18 C > Wikipedia image by FA2010

2 Frame.png

Photo Frame 18 C France Wikipedia image by FA2010


Flickr image by Plum leaves


Photo image Florence > Wikipedia image by FA2010


Door Frame emulating the Photo Frame 18th C Venice > Wikipedia image by Hiart

Few Art Nouveau experiments altered the door frame and shutters with floral ingress. These experiments saw 3D modulation and integration of the architectonic elements along with masking and framing appendages. These were craft and technology based multi-material solutions devised along with the form of the building -in a way an integrated architectural resolution.


Bloomsbury Tavern Night view of windows > Flickr image by Eric Huybrechts

Openings have a dual personality, of the inside and outside, and both have been differently treated for functional, technical and scaling reasons. The framing references are different for both. On the interior face great many masking elements including soft furnishings are available to condition the view outward. The options on outer face are fewer, but major one is the day time perception of the opening, in complete contrast to inside illumination at night time.

Ney York Times Night View

New York Times Building NYC Night time > Wikipedia image by Jleon (talk)

The masking of view out or inward, is done through real or make-believe depths formed by repetition of series of identical, receding or increasing frames. Such multiple frames occur in colonnades, corridors, passages, avenues and walkways.


Corridors of Miranda House Delhi. Repeat elements framing the view >Wikipedia image by Dell335

Framing can provide its own third dimension, or the depth aspect to the opening. The depth aspect was primarily used for inducing a perspective view. Framing took advantage of depth of the massive structure, such as in Romanesque period. The sides, top and bottom edges of the openings, on both the inside and outside faces, were chamfered or cut square. The additional surfaces of intrados and extrados were articulated to not only enhance the perceptible extent of the opening, but treated with sculptural texture for adding to the extent of a visual surface. Side surfaces of the openings created a frame within frame.

..92 durch ..94 ersetzt

Pediment over openings Siracusa Cathedral Sicily Italy > Wikipedia image by pjt56—




Post 574by Gautam Shah


Domains are nominally, Physical, Metaphysical and Metaphorical. At another level domains could also be Real or Virtual. Physical domains are landed or with dimensioned and marked territorial features. A Metaphysical domain is more relevant by the spread or extent of its activities or effectivity. Metaphorical domains subsist on analogical connections. Such domains rely on thought, concept, traditions, customs, beliefs, style, ethnicity, etc.


Spatial Domain > Wikipedia image by VeronicaTherese

A space domain has few distinguishing marks, such as the Core and Peripheral zones. Space domains are proximate or converge. Domains have users and their social interactions are triggered by the spatial organization of the domains. In the following FOUR articles, these issues are discussed.









Monte Alban Archaeological site Gran Plaza Oaxaca Oax, Mexico Wikipedia image by Hajor Released under cc.sa and/or GFDL

Physical domains are landed or with dimensioned and marked territorial features. Physical domains have transient core and peripheral zones. The peripheral zones react with the local environment and so can have many spatial as well as temporal variations. Core-zone is a common or community area and continuously shared with others. Core-zone accommodates relocatable amenities. Compared to this, the peripheral areas are assigned to specific tasks, but the tasks shift around to take advantage of changing environment. The house in charge person, wife, mother or in few instances home-based craftsman occupies the core area. Enrichments occupy the boundary sections and define the space such as sanctimonious, utilitarian, storage etc. The core area often shifts towards the daylight zone near openings.

The markings of domains are characterized by the ambit of sensual perceptivity, communicable distancing, consistency of the spatial characteristics (coherent space and environmental conditions creating a unique space segment) and acceptability or confirmation by a section of the society.

Metaphysical domains have a non physical spread. Such domains cannot be perceived through the sensorial system. Their presence is intellectually and intuitively confirmed by the believers, but for others it remains obscure. Such confirmation requires a unitary image, so a strong centric core zone emerges, often with a definitive peripheral zone. To reflect the enhanced participation and democratic nature, the peripheral zones are made transparent.

Revered spaces, shrines, historical sites, haunted buildings, buildings without utilitarian functions or commercial purposes have a strong metaphysical genesis. Beliefs borne out of instincts, concepts, experiences, etc. are rooted to the core area. In the peripheral or threshold areas these have thinner effect, so are impacted by the ideologies flourishing in the neighbourhood. Inhabitants’ beliefs also may be born as a reaction (antithetic) to the neighbours’ ideology, and in such cases may not have any core roots.

Metaphysical entities like home, family, group etc. come into being in a space where communication, exchanges and the intimacy occur more efficiently then elsewhere. Such space units are also ‘home’ to many other beliefs and notions. These are associated with a person or group, and so have a strong presence. Metaphysical zones centering on a belief or remembrance of an event, person or entity are sustainable so far as believers, followers exist, conduct activities to further the belief or notion, or till a counter effect comes to be accepted.

The beliefs as a metaphysical factor cast a space that is sharper at the point of the origin, and prone to diffusion elsewhere. But for belief to survive and gain strength peripheries are necessary. Churches, temples, Ashrams have strongly defined territory through peripheral structures like gates, walls, Gopuram, etc.

Metaphoric domains require very little estate, however to support and enhance the metaphoric presence some spatial characteristics are employed. There being a single generative concept, the peripheral zones have a very small role and so a thin presence. The environment within is static, reflecting nearly solid barriers. Amenities, facilities and enrichment are purposive only, and so their relocation or any shifting of other elements due to them is not required.


Global Internet Realm > Wikipedia image by Shijan Kaakkara

 Convergent or Proximate Domains

A physical domain is a unique spatial entity. But often other domains are very close-by or converge onto it. The effect of it is seen as inward and outward transgression of the peripheral areas. The transgressions occur to enhance the spatial character, or take advantage of the neighbouring or convergent domain. Ariel windows, Bay windows, Chhatris, Balconies, Verandahs are typical outward transgressions, whereas Chowks, cutouts, shafts, courtyards, are examples of inward transgressions. With such transgressions the peripheral areas change, but core zone remains unaffected. Perhaps the only change that occurs with the core zone is due to the shift towards the vibrant periphery.


Convergent domains Edinburgh Castle and surroundings > Wikipedia image by Kim Traynor



Domains have Three basic constituents Formatted Space, Environment and Individual/s. A domain, as a space, is a segmented entity. Its primary segments are Core and Peripheral zones. A core is usually single, but peripheral zones are many. The core and peripheral zones often converge. Different peripheral zones also impinge over each other. The formatted space endows an exclusive character to the domain.

Core Zone of a space domain represents the commandeering mechanism and has a natural tendency to be singular and focal. The core zone has consistent environmental and spatial qualities, but its position within the domain may be transient. The shift is due to environmental conditions, functional needs, available facilities, amenities and enrichments.


Core versus Peripheral zones Flickr image by Stortinget

Core zones gain strength by the shape (form) of space. Space forms like concentric, conical, angular, circular etc. are focussed and so enhance the nature of a core zone. However, very extensive domains lack an effective focus. A dominant enclosure on one or few sides of a domain creates an inviolable shield, an identity of belonging, or a sense of orientation.

A core zone can be formed by the dimensional and cognition reach extent of the occupant. The reach extent also scales the domain space. Such core zones are very personal, so sustain themselves independently. A core zone may not exist clearly where very vivid surroundings form strong peripheral areas.

Core zone amenities shift due to spatial needs and environmental changes. This leads to demountable or relocatable amenities such as handy or mobile tools, multipurpose equipments, plug in tools, wireless gadgets, miniaturized appliances and modular and system’s engineering approach in design. Compared to these amenities in the peripheral zones are strongly dependent on the architectural and structural systems, and so are static.

Historically a core zone of the ‘Home’ was the ‘hearth’ (literally meaning a focus). It was considered safe, intimate and interactive for the family. The hearth was centric, without any abutting elements like a cave wall or a rock face. The ambit of the core zone was determined by the climate, the scale of the space, number of participants and level of interaction, and the degree of personalization required. There was only one such zone in the dwelling.

The home in charge -the mother was master of the core zone. Her role and presence had become so obvious that ‘the hearth, the mother and home’ were synonymous. In tribal and aboriginal homes the core area is a female domain. The core zone, was the natural centre of metaphysical spread ‘the home’, as much as the mother was de facto guardian of culture.

Today, however the hearth is not an inevitable element for safety, security or comfort. It is the quality of barriers and other gadgets that provide this. Dwellings now have many sub domains each belonging to an individual, smaller group, or configured for a set of tasks. Very few activities of the family occur at the one place and are scheduled in the same time slot. But the family members do share a lifestyle developed through metaphysical markings like beliefs (customs, taboos, etc.) and the metaphoric means.


Multiple or Convergent Core zones at Water Tower Place Chicago > Wikipedia image by Cosmos1976

Multiple core zones occur in very extensive domains. Such domains have weak central command and so allow formation of groups. The groups separate out primarily due to needs like physical accommodation, need for social intimacy and reach of communication. The groups may not seek a distinct territory or qualitative space segment, however, frequent such occurrences, show the existence of multiple qualitative space segments.

Multiple core zones also emerge where several overlapping or closely spaced domains operate within a larger domain space entity. Such core zones share the same spatial segment simultaneously or are programmed in same time schedules. Here the consistent elements are: spatial characteristics, environmental features, participants, amenities, facilities, tasks and activities. Multiple core zones tend to remain together, but often get separated by strong peripheral areas.

Arab tents had dual core areas within the basic form of the tent, one occupied by the women and used for main cooking, and the other half is used by men and for preparing coffee, etc. These two sections are divided by a mass of stored elements, such as mattresses, floor spreads, etc. The side flaps of the tent are stretched out to create peripheral zones of various sizes. The stretched width and the angle of the flap are conditioned by the sun’s position, wind direction, nature of tasks to be conducted and the need for privacy.

Cooking and dining once (and still do in many societies) belonged to a single core zone, but were separated as two concurrent core areas. These two core areas were further separated by a pantry area that was a peripheral zone to both. Entrance is buffered by a lobby, foyer, entrance hall, or vestibule from other sections of the house. Yards, verandahs, porches are used to separate out the building from the street.

Small or one room houses have multiple core zones. These zones exist in terms of activity space spreads, which often overlap in time. The multiple core zones match the space layout characteristics, such as four corners, the area near the door or window, the area abutting the wall, the axis formed between two opposite side opening. Traditional Sarai rooms are two and half man width (2.0+1.0 mid passage+2.0 = 5 Mts or 16.5 Ft). This allows two families or their men or women to occupy a side. The depth of the room is of less important.


Centric Core zone A Pompeian Interior > Wikipedia image

Centric and Non-centric Core Zones: Domains with emphatic barriers create a centric space entity. But domains with breach-able barriers or loosely defined peripheral identities have overwhelming outside influences that create a non-centric space.

Domains with a substantial core zone tend to be spherical. Such spherical domains with a centric core zone are invariably static, compact and finite. Domains with an opaque boundary are also similar. Domains with weak boundaries have vibrant peripheral areas. A shift of the core zone towards a benevolent peripheral area becomes inevitable. A very extensive domain also provides greater opportunity for such a shift. Non-centric domains have some directionality as these are strongly affected on one edge, or are attached to other domains. Non-centric domains require far more definitive space formatting then centric domains.

Historically kingdoms have had effective spread of their domain depending on how far and fast they could travel. Mughal kings with their luxurious retinue could not visit the peripheral areas, frequently resulting in weaker control. Compared to this Changiz Khan’s Kingdom extended far & wide, but not for very long. Lecture halls or areas where concentration is required have opaque boundaries and conical shape. A colony against a fort wall or along a river coast is a linear domain, subsisting on the strong peripheral advantage and so apparently may not have core presence.



Peripheral zones are vulnerable to outside influences due to their closeness with the edge and also their distance from the core section. A core zone is dominated by the domain’s main and common activity, but the peripheral zones are distinctive escape areas and so have diverse utility. Peripheral zones derive their functionality from nature of barriers. Peripheral zones emerge as an antithesis or concurrent space segment of the core zone. The peripheral zones are affected differently by the directional and temporal aspects of the environment. A peripheral zone is often relevant only for a while, to an individual, or for an activity.


Peripheral emphasis in space > Choir and East side of the rood screen of Saint Cecile Cathedral France > Wikipedia image by Benh LIEU SONG

Once the extent of the peripheral zone was determined by the concern for safety, warmth from the fire, the need for privacy, scale of the task-activity and distancing from elements (to reduce their intensity and reach). The barriers, where available formed the edge sections of the peripheral zone. These were also used for reclining, resting, hanging personal items and for expression (artwork).

Peripheral zones are primarily shaped by the core zone, but are more often affected by the nature of the periphery of neighbouring domains and happenings beyond. The edge areas allow a person to selectively taste the happenings of outside-world even while remaining inside. Peripheral zones are flexible, i.e. can be stretched or contracted from their nominal spread. Domain transgression occurs through the periphery. Peripheral zones are dual faced, so one can orient an activity towards or away from the core area.

Peripheral zones often develop as an acutely specific zone. Study nooks in bedrooms, coffee rooms with the dining area, hobby zones in kitchens, home offices with vestibules, retiring rooms in private offices, vaults in banks, store rooms with homes and offices, wardrobes, shower stalls, change rooms in boutiques, cashiers’ cabins, pilot or driver’s cabins, reception counter, janitor area, services ducts, podiums in lecture halls, green rooms with a performance stage, ticket booths, telephone kiosks, are all examples of peripheral zones separated from the core zones.

Peripheral areas mark the end of one space entity and beginning of another one. Peripheral zones are thresholds to other space entities, and occur or are perceived to be an intermediate or buffer state. Thresholds are interactive areas, and alter (qualitatively) the elements transiting through it. Their activeness arises from their level of transparency and thickness (mass of the barrier), both of which control (rate, direction) the exchange. Thresholds also occur as an interstice on the overlapping barriers, where two effects are simultaneously operative.

The space barriers, such as walls, roofs, awnings, curtains, partitions, ceilings, etc. form a focussed space. Yet these barriers also create segments that are more strongly attached to the periphery. The barriers, however, are always prone to change from outside effects. There are two distinct places for group behaviour mechanisms -the focal and the peripheral sections.

Lecture halls, bed rooms, modern kitchens are single activity and so focussed units, but road side cafes are peripheral. An older style kitchen sourcing its services off a wall was more peripheral, whereas modern kitchens have island workstations, is more of core centric arrangement. A drawing room like the dining area is focussed for an activity, but a family room is multi functional and so less focal. Fire was the focus of the primitive home, and TV has become the current focus of home gathering. A physical feed-based work station is peripheral, but a wireless notepad computer offers flexibility of being anywhere.



Domains as Space entities are used by owners or occupants, architectonic elements and spatial objects.

Space and Users or Occupants: For a user, occupation of a space triggers a set of behaviour. For occupation the user has to find the most appropriate location, orientation, body posture, facilities, amenities, and environment. One of the most natural and primal way is to search a focal location in the space. This is done by finding geometric junction (cris-cross of many spatial lines), by locating spatial balancing or focussing centres, by orienting to some feature of the space (like an entrance door, window), by being closer to something (wall, column, furniture), by associating with other occupants (through ‘social distancing’) or by creating new patterns (angular, floral, concentric, diffusive). Here other operative factors are: range of cognition (capacity to perceive), physical proximity (level of social interaction), nature of relationship (age, sex, social status) and possibilities of expression and communication.


Pennsylvania Station NY > Wikipedia image by Alan Turkus

The user also needs to have some control over the space, such as: Opportunity to change the location and position (including the posture) within the space; Choice to interact or not with others; adjust the spatial quality at micro level (scale and schedule-wise) and thereby the environmental conditions; Be noticed or notice others; Form sub-core zones, Shift to peripheral zones and be able to conduct exclusive tasks, and Way to leave the space either in full knowledge of others or without being noticed. A user, unless is an owner of a domain, will not be allowed to change the architectonic character of the space, import, shift or relocate amenities and facilities, alter the quality of environment that perhaps is not acceptable to others.

In very large spaces adjacent walls, hedges, mid columns, flower pots, water fountains, lamp posts, flooring, ceiling, and such other patterns and objects provide points of anchorage for space occupation. Spatial configurations like a stage, podiums, projection screens, speakers, singers, vivid objects, also hold interest by providing involvement.

In parties, hosts make a conscious effort to break intimate formations by removing or adding key or active persons, or repositioning and rescheduling the activities. In clubs and places of entertainment the environment (lighting, furniture, equipment) and programmes are reset to shift the focus off certain space segments. Group gatherings are designed to occupy different space segments (hall, terrace, lounge, library, garden lawn, etc.), variegated environmental conditions (bright vs diffused illumination, change of music, etc.) and diversions (toast by the host, magic shows, musical renderings, dancing, etc.).

Interpersonal Relationships and Spaces: Groups require space for interpersonal relationships, expression and its perception. However, the ‘depth’ required for such interactions in physical domains is irrelevant for virtual domains like telephony or video conferencing, chat rooms, hangouts, etc.

Interpersonal relationships have little relevance in acutely sized and highly defined spaces (ergonomically sized, shaped and provisioned with facilities), such as: toilets, kitchens, storerooms, study nooks, booths, etc. Larger spaces such as bedrooms, drawing rooms, office cabins, etc. allow interpersonal relationships, often in multiple varieties simultaneously.

Ideal place for the interpersonal relationship is the core section. This has least external disturbance, so should be an area of tranquility affording privacy. Yet peripheral zones are more preferred as a place for intimate relationships and commitment. In restaurants, cinema halls, public parks, large waiting areas, people move to corners and edges for seclusion. Threshold areas though peripheral, are public and vibrant. Threshold areas are considered ideal for noncommittal interaction.


Group behaviour mechanism in Space Image Flickr source: Neko II > Wikipedia image by Sultry

The group behaviour mechanisms exploit the space characteristics to infuse emotional and social functionality. Group behaviour depends on individuals as well as interactions among such individuals. An individual projects psychological and sociological responses. The group behaviour though erratic has a degree of commonality – raison d’être (cause) of formation of the group. The common approach of the group is an assurance that their peculiar behaviour is not an aberration but a probable happening.




Post 573by Gautam Shah







Air entrained coffee of South India > Wikipedia image by Babithajcosta





Plasma cutting machine Wikipedia image by Steve Brown Photography






Compounded materials occur in following forms: (Medium in Phase)

  • Solid in Solid > Alloys
  • Solid in Liquid > suspension, solution, dispersion
  • Solid in Gas > smoke, airborne dust
  • Liquid in Solid > gel
  • Liquid in Liquid > emulsion, mixture
  • Liquid in Gas > fog, aerosols
  • Gas in Solid > solid foams
  • Gas in Liquid > froth, liquid foam, aerated soda
  • Gas in Gas > atmospheric air

Cutting tools of Alloys > Wikipedia image by Glenn McKechnie




Smog at Brighton UK by Wikipedia image by Richard Rutter




Hai dressing gel > Wikipedia image by Bangin




Aerosol cans > Wikipedia image by http://streetflies.org/stue



Aerogel > Wikipedia image from NASA







Post 572by Gautam Shah




Fortified domain –Carcassonne Castle Wikipedia image by Petitemontagnedujura
















Neighbourhood as a domain >> Wikipedia image by Challengethelimits


Berlin, III. Weltfestspiele




Beatles cult >> Wikipedia image



Air traffic controller over an air space domain



Vsat at Salaga Ghana >> Wikipedia image by IICD http://www.iicd.org/photos





Post 571by Gautam Shah


Metals parts need surface treatments and cleaning for conservation, restoration,  decoration, reflectivity (shine), dulling (removal of gloss), better hardness, surface integrity, prevention of corrosion and in preparation for the next treatment. Metal components get both organic and inorganic substances deposited from various lubricating oils, corroding environments and substances, and deposits from hard water etc. Metal surfaces need cleaning for removal of residual products from earlier processing, weathering, depositions during storage and transport and environmental contaminations. A cleaned metal is comparatively more active, and so may need, immediate next treatment, to prevent corrosion and contamination. So metal surfaces often receive simultaneously the processes of cleaning, surface activation and protection.


Metal surfaces needs to be smoothed, scrubbed or scoured to receive next set of treatments. Cleaning processes are employed to discharge electrical ions from the component. Cleaning processes are designed to serve several purposes, such as cleaning, scoring and protective coating. Cleaning occurs at a raw material stage, product formation stage, in preparation to other finishes, or just prior to a marketable finish. But there are two distinct stages, at manufacturing plant and on-site applications.


Center-less grinding  Wikipedia image by Wizard191

Alkali cleaning is typically done with caustic soda (NaOH) which removes all polar substances such as fats and oils. The vegetable and animal oils are converted to glycerol and soap, and the petroleum-based oils and grease are emulsified.

Acid cleaning, like alkali removes ionic deposits from the metal surface. Depending on the secondary products like salts determine the quality of acid to be used. Pickling process removes oxides from the surface by a dissolving liquid. For steel, a warm dilute sulphuric acid, and in some cases hydrochloric acid, hot or at normal temperature, is used. However, for some alloy steels nitric acid, is needed. Acid and alkali both processes require post treatment ph. balancing rinse or treatment.

Solvent cleaning: the articles are washed with a petroleum solvent or undergo cleaning (de-greasing) by vapour, in which a solvent such as tri-or tetra chloroethylene is heated in a closed system, and its vapours are condensed on the metal surface.

Emulsion cleaning: the metal parts are immersed in a warm mixture of kerosene, a wetting agent, and an alkaline solution.

Mechanical cleaning use force of air or water jet and sonar waves to remove partially attached particles. The process may include fine particles like sand, silica, metal grit etc. to blast the surface for the same purpose.


Electrolytic cleaning: the articles are immersed in an alkaline solution and a direct current is passed between them and the other electrode which is usually steel.

Ultrasonic cleaning is used for blind holes or gears packed with soils etc. Small particles embedded in crevices get detached due to ultrasonic waves.

Plasma treatments bombard a surface with electron ions to break the surface level chemical bonds and change the chemical composition of the surface. Plasma treatments may also remove variety of material types such as paints, polymers, glass and ceramics.


Statue of Perseus Piazza della Signoria Florence After cleaning Image by Jrousso at Wikipedia En

Metal cleaning Tools and Techniques

The metal products are small items like nails, rivets, long rolled sections, drawn items like wires, woven items like lattices, entwined items like ropes and barbed fencing, hollow pipes and tubes, or solid castings. Other products include assemblies like automobile bodies, boxes, cages, machine housings and structures like a truss. Metal components are single or multi-metal items, composites with polymers, ceramics, etc. Art restorers have to deal with metal objects of unknown composition, ageing, and coated with natural or applied substances. Art restorations require reversible processes, so if a treatment is found unviable it can be fully reverted. Metal products in continuous line productions are moved through several sets of electrodes, which, submerged in a cleaning liquid, electrolytically generate hydrogen gas at the steel surface for lifting residues off the material.


Sand-blasting Wikipedia image by National Institute for occupational safety and health NIOSH USA

Hard substances like metal nodules or slags are removed by abrasion or high pressure air or water jet. Soft materials like soil etc. are removed by brushing. Brushing may be carried out dry or wet and with scrubbing and scourager agents. Brushes with natural hair, synthetic fiber, metal fibres and wires are used. Abrasive materials like A Carborundum, sand grit, metal particles etc. are blasted on the surface to clean up the surface. In some instances like manufacturing of nails, abrasive materials rotated in ball mills with nails, to achieve high polish. Ultrasonic sound waves are also used to remove particles.