by Ora Lassila / So Many Aircraft
Sometimes a single kit is not enough to get you the result you want, or the kit has problems that are easiest to correct by taking parts from another kit. This approach to model-building is called "kitbashing", and while you may think this could be costly, you will want to do it if the end result is what really matters. For me personally, the turning point was dispensing with the thinking that 1 kit = 1 model, and starting to think of kits as mere "raw material" for models.
In an ideal world, parts from one kit would be a perfect fit for another kit. Of course this is not always the case, due to two reasons: first, kits are engineered differently, and second, kits are not always completely accurate wrt. the original objects they represent. Most often I notice this when fitting a canopy from one kit to another kit (because of accuracy, or lack thereof) or when using the cockpit interior from one kit in another kit (because of differences in engineering). In both cases, you may need to work the parts involved to make them fit, by either sanding off something or "building up" some structure using, say, styrene sheet and putty.
Here are some examples of my own projects where I used kitbashing:
Sometimes you want to use aftermarket parts made for one kit in another kit, and this typically involves some "surgery"; parts engineered for one kit will not fit in the other kit without some modification. Cockpit interiors are a typical case of this.
Related to what I have described above is the case when the kit you use requires substantial parts of the final model to be scratch-built (see my model of a powered version of the Grunau Baby glider built from a standard Baby kit), or maybe you end up scratch-building most of the model, but can utilize some kit parts (my Bereznyak-Isayev BI-1 is a good example).