Joinery for a Melamine Box with No Doors

Advice on how to connect the top and sides of a pass-through mailbox made of melamine. June 17, 2012

I never do this type of work, however I have to bid a job that is just one box 90w x 24h x 16 d with a horizontal fixed center shelf and vertical dividers 3"oc (double decker mail box). It slips into a wall and has access from both sides. There can be no fasteners showing. What is the best way to join the sides to the top? All exposed edges will be covered with PVC edge. Iím guessing dowells? I donít have a horizontal boring machine.

Forum Responses
(Cabinetmaking Forum)
From the original questioner:
Correct me if Iím wrong, but how well does glue stick to melamine? Or are you just using the surface area of the biscuit joint to do the holding?

From contributor Y:
That's about the easiest way I know and yes, you are relying on the glue on the dominoes or biscuits.

From contributor D:
Use biscuits for alignment and Roo glue to hold it together.

From contributor S:
I would use dowels (I have a boring machine). If you do not have the equipment mentioned so far confirmats and melamine glue will work.

From the original questioner:
Biscuits and Roo glue it is. Thank you.

From contributor F:
Find a CNC shop who can cut your parts with blind dados and edgeband parts for under $150 including materials. Glue and clamp the parts with melamine glue from Franklin (makers of Titebond) or Roo glue.

From contributor L:
Roo is a lousy wood to wood glue. When I used biscuits I used yellow glue for the biscuits and a bead of Roo between. I'd think that yellow glue on blind dadoes would be stronger because the primary bond is wood to wood.

From contributor U:
Actually we use Roo glue to join a lot of wood to wood, metals, and some plastics. It is a very good gap filler and glues many materials together, just has a lot longer set time than PVA's. Wood to wood strength seems less under normal conditions but if you need a little gap filling and the glue line is not visible it works great.

The idea for the melamine is not to dado just glue melamine to pb core and use just a few biscuits for alignment. The Roo glue works good in the biscuit joint also, again just with a longer set time.