Scratch building is the process of building a

scale model A scale model is a physical model which is geometrically similar to an object (known as the prototype). Scale models are generally smaller than large prototypes such as vehicles, buildings, or people; but may be larger than small prototypes ...

"from scratch", i.e. from raw materials, rather than building it from a commercial kit,

kitbashing Kitbashing or model bashing is a practice whereby a new scale model is created by taking pieces out of kits. These pieces may be added to a custom project or to another kit. For professional modelmakers, kitbashing is popular to create concept ...

or buying it pre-assembled. Scratch building is easiest if original plans of the subject exist; however, many models have been built from

photograph A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now create ...

s by measuring a known object in the photograph and extrapolating the rest of the dimensions. The necessary parts are then fashioned out of a suitable material, such as

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adapta ...

plaster Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "re ...

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...

metal A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...

, polymer clay, or even

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distribu ...

, and then assembled. Some purists consider a model not to be truly scratchbuilt unless all of the parts were made from raw materials. However most modellers would consider a model including commercial detail parts as scratchbuilt. Scratchbuilding a new body onto an altered ready-to-run chassis is also acceptable.

Motives

The reasons hobbyists scratchbuild may vary. Often a desired model is unavailable in kit form in the desired scale, or entirely non-existent. Sometimes the hobbyist may be dissatisfied with the accuracy or detail of kits that are available. Other times a hobbyist will opt to scratchbuild simply for the challenge. Less frequently a hobbyist will scratchbuild out of economy, as often the raw materials cost less than a packaged commercial kit.

Techniques

Most hobbyists develop their skills by building kits, then progress to

, where various kits are combined to create a unique model before attempting to scratchbuild. Sometimes scratchbuilders utilize discarded parts of other models or toys, with or without modification, either in order to speed up the building process or to allow the process to continue in spite of certain parts being difficult to make. Some companies sell parts that are of little use to anyone but scratchbuilders.

Building stock

Building stock, in whichever material, can be plain sheets, strips, bars, tubes, rods, or even structural shapes such as L or T

girders A girder () is a support beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing ''flanges'' separated by a stabilizin ...

. Stock can also be embossed or textured to replicate a certain prototype material (such as plastic sheet embossed with grooves to mimic a scale brick wall). For example, to scratch-build a small board fence, the modeler could use plastic rod stock to form the vertical posts, then use plastic bar stock to form horizontal rails affixed to the posts, lay plastic strip stock vertically on the horizontal rails (perhaps 'distressed' with a wire brush to mimic wood grain, or by using thin strips of actual wood), trimming the top and bottoms of the strips to be even, adding details like nail holes (using a small pin), and then finishing and

weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs '' in situ'' (on site, with little or no movement ...

(making a model look like it has been used via dust, dirt, stains, and wear).

Method

There are as many ways of scratch-building models as there are modelers, but generally the modeler obtains plans of a prototype, or designs their own, transfers these plans to paper or other material as patterns (much easier since the arrival of household computer printers and copiers), and uses these patterns to cut, trim and affix the stock together to form the model. Finishing work (such as sanding and polishing, painting, weathering, distressing by forming dents and rust, dust, etc.) is done to complete the model and (hopefully) bring it to a lifelike state.

References

* {{DEFAULTSORT:Scratch Building Scale modeling