Primary HM fiberglass board material for general use pine, Paulownia. Paulownia heavier than pine, but the strength is better. In doing airplane model aircraft on aircraft weight control requirements more stringent, in general, is a mix of pine and paulownia. And can only be done with a wooden frame, but also skin wrap. Now with multi-use foam, just to buy large pieces of foam like that, do a solid structure, you can use an electric wire cutting, you can also use sliced. Internal only need to dig out space to install the remote control and engine room, without any basis is very difficult to succeed. There's a direct cut with a knife KT board directly under the assembly. For details, please see our web site: http://www.tianhao0769.com