If you don't want to alter the wings structurally or add too much weight, I would say spray the outer surface with a polyurethane lacquer.
Foam rc airplanes are a wonderful hobby entailing the building and flying of model airplanes that are constructed out of a lightweight but durable foam. More information on this hobby can be found at www.rcfoamairplanes.com.
I don't really know anything about rc airplanes, but there is lots of information online or in catalogs. Here's a link to an rc apriplane dealer: http://www.hobbytron.com/RCAirplanes.html
Information on RC airplanes is available in many books in book stores, libraries, and hobby stores. There are also many websites that have a lot of information on RC airplanes.
RTF airplanes are pre-assembled RC airplanes built to eliminate assembly time. This option is typically used for younger children or those uninterested in the construction of the planes themselves.
RC model airplanes are just one of the styles and various brands of radio controlled models. For a selection of RC flying machines complete with pictures check out http://www.nitroplanes.com for RC model airplanes, jets and helicopters.
RC airplane parts tend to be used in specific hobby airplanes or in only a few hobby airplanes that it will fit in. There are some parts that are interchangeable among other planes but that is the exception, not the rule.
ebay
You can purchase model RC RFT airplanes online by visiting http://searchrc.horizonhobby.com. The prices for these plains range from $75.00 and up. Enjoy your model.
ebay has a large selection of used rc airplanes with prices starting at $33 and going up to $1,300. The site can be found here: http://shop.ebay.com/i.html?_nkw=used+rc+airplanes
Assembling RC airplanes can be time consuming. The parts are very detailed and need care when putting them together. The reward of building the rc airplane compensates for the time used to build one.
The price of RC airplanes varies greatly depending on the brand, model, and location of purchase. It is possible, for example, to find such an item for as little as $50 and for as much as $500 and beyond.
Any hobbie store you can find foam RC airplans and other airplanes yu might want. Ask the stor clerk if he knows where to get them and you should be on your way.