At some point the engine cowl must be custom fitted to your aircraft. Very few cowls are available that don't need extensive trimming, fitting and cutting to provide a good fit to the fuselage. This effort requires cutting the fiberglass material that comprises not only cowls but also other components such as wing tips, fairings, wheel pants and more.
Traditional methods for cutting fiberglass include the use of somewhat dangerous cutting tools (high speed cutoff wheels) and production of clouds of hazardous fiberglass dust. Care must be taken for personal safety while working on this aspect of building your aircraft..
An inexpensive power tool can address these issues by removing the danger of cutting fingers or eye injury AND drastically reducing the fiberglass dust cloud. Take a look at this short video and see what tool may be an excellent alternative to use when you need to attack your fiberglass projects!