Jointing options
To glue the pieces together you will need clamps to lock the timber in place while the glue dries. I have about half a dozen of these clamps and if I need more I can always borrow them from my neighbour, as he does from me from time to time. My clamps, mostly, are not high-quality, expensive ones but they certainly do the job.
I have inserted biscuits to the joints when gluing the timber together. This adds strength to the joint but, in my view, certainly the base and the centre shelf are thick enough to allow good strength by gluing them together without the biscuits. If you do not have a biscuit slotter you might consider using dowels. The holes for dowels should be carefully marked out and drilled.
Take a little time with the glue-ups to ensure that you have at least one surface at which the three pieces all line up. This saves a lot of additional planing or sanding when finishing the base. I usually place greased cooking paper on the clamp where the timber sits to avoid the water in the glue causing a chemical reaction with the steel of the clamp and leaving a black mark on the timber. Once the glue is dry, trim the base to the required size.
The shelf and the top
The centre shelf is 280mm wide so I started with two pieces of 150x40mm, machined them to size, and glued them together — the same process as used for the base using biscuits.
The top is 230x19mm and while I might have been able to find some timber that width I decided to glue two narrower pieces together to try to alleviate the risk of it bowing due to the ever-changing climate conditions. With this timber only being 19mm thick, it is more desirable to use biscuits or dowels to give the joint that additional strength. Again not a