Finishing a model airplane is usually thought of as the last two or three steps needed to be done before your model is ready to fly. In reality, no amount of "finishing" work during J the last few steps can make up for a poor building job. A proper finish should be your ultimate goal throughout the entire building process, not just an afterthought thrown in at the end. The finishing process can often take longer than the initial framing out. My most recent project was a Hall Bulldog and it required a high-gloss finish, so most of the work was done in preparing the various model surfaces for paint. Building the Bulldog was almost a side show. Generally, matte finishes are more forgiving when it comes to surface imperfections. They may be seen under certain lighting conditions, but glossy finishes show everything and are very unforgiving. I built the Bulldog using so-called conventional construction methods — balsa sheeting for metal areas and fabric covering over open framework plywood and balsa. No matter how hard you try. balsa sheeting will eventually show grain due to expansion and contraction if it is filled and finished without first being stabilized. While there are other methods, I use fiberglass cloth and resin to stabilize balsa surfaces. Although I have used both epoxy and polyester resin systems to affix fiberglass, such methods can get heavy in a hurry. For my smaller and mid-size models. I have settled on using water-based varnish (satin Minwax Polycrylic) to apply the fiberglass. This system does not yield as hard of a surface as with a two-part resin, but it is close, and it's a lot lighter. The steps I employ after the glass treatment firm up the surfaces even more.
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