Supplied coiled in square boxes which are referred to as “cheeses”, this material resembles a coil of light rope and is used with a fibreglass depositor machine (chopper gun) thus the alternate name “gun roving”.  Over the years, the lower price and availability of these guns has made it worth considering their use even if you are building a single boat. You will always get your money back when the boat is finished and, for a modest outlay, save a lot of time and expense in the process.

   Using a depositor gun, the continuous roving is cut into short lengths (like CSM) and deposited by the gun, which also mixes the resin and catalyst. They all come together as they leave the gun head, and are sprayed simultaneously on to the job.   The result is a quickly applied chopped strand mat lay-up. This same gun can also used as a resin depositor only, to wet out the alternate layers of roving or fabric.  This is the procedure used for production moulding but is equally suitable for one-off male moulded boats.   If you are considering using a female mould or laying up your hull using the “Panel Construction” methods, then the chopper gun and continuous roving may be a great investment.  

   Gun laying requires an experienced operator to get a perfectly even layer of mat and resin to the job.   When building on a male mould, evenness of the application is most important, so some experience with the gun is an advantage although not difficult to learn.