RE: Bird of Time- wing tips
Well I did it with mine just like you said. I packed the triling edge up as I built it on the board, then put the top sheeting on. Its about 10 years ago but I guess I added 3/16 to 1/4 inch at the tips.
A friend built a BOT at the same time and so I have flown this model both with and without washout. It is a very forgiving model without washout but with washout it is outstanding. My model can be mishandled in a ludicrously crass way without biting. This means that I can thermal very slow and low without fear.
I have much more sophisticated all moulded models these days but I will never be without my BOT.
Regards,
John.