Very few people glass the lip. This actually came up on the bulleten board a year ago. Assuming you're doing a Nick Shade style coaming and have glassed it, the lip has plenty of structrual integrity and really needs only to be coated with epoxy. You can certainly glass it if you want, however it's a chore to get to wet out with no air etc. and when you're done you achieved nothing but another glass area to fill the weave etc.