Hi Mark....how 'hollow' do you manage to make shapes like that? With a top surface that is almost horizontal, to what extent do you manage to undercut it? I can imagine terrific difficulties hollowing inside a shape that you can't see into.
Les
Hi Les
This sort of piece being turned from wet wood has to be turned thin and to a constant wall thickness or they will crack during seasoning due to the difference in shrinkage for the differing thickness of areas.
To answer your question the wall right from the rim into the base is around 2-3mm and I use a light and callipers to check, here is a view into the lower half of the form.
![](http://i572.photobucket.com/albums/ss166/fullcircle1/small-3_zpse2461d9c.jpg)
There is not a problem with hollowing into such a steep undercut. Infact you can with practice go much steeper and even back on your self. You need a hollowing tool with a head that can be articulated to be able to achieve it through such a small hole as well as quite a few years practice.
Here is a cutaway of a form showing a steep undercut.
![](http://i572.photobucket.com/albums/ss166/fullcircle1/undercut_zpsbbaa3935.jpg)