Margni, why use mdf and not solid ash wood. Once you figure in the time to veneer in all the mdf for this project it will easly pay for itself. Not to mention the piece will last alot longer than the mdf. Is it a cost issue or do you just want to try out veenering. Ger gave you some great links with a load of information. If you dont read them one thing that I will say is try out glueing test piece to see if glue bleeds threw. Nothing like ruining a project because of glue.