Ok . Firstly Id like to say thanks to Thomas Altmann , I followed his direction from the design of my Caja Cajon .
http://www.ochemusic.de/artcajon.htmThe plywood at my local wood yard had decent 5 ply 6mm and 3ply , its not beech or birch finish but strong enough .
I am very pleased with the results strong construction . I used Gorila glue and finished it with Labern black polish used on Grand piano `s . ready to Rumba .