Making a bookcase - need some advice

[Paul Moore]

Hello,

I'm about to start making a free-standing bookcase. When finished, it will be 20cm deep, in four separate sections, each about 70cm wide, and separated by vertical supports 250cm high. I was planning to cut slots in the five supports with the router to take the ends of the shelves. When finished, the bookcase will be screwed against a wall.

My question: is it a good idea to glue the shelves into the support slots? I was thinking from the point of view of the expansion/contraction of the wood during the year due to moisture changes. The room is centrally heated.

Many thanks, Paul

[BigWallop]

A free standing book case that gets screwed to a wall, is not free standing anymore. Wouldn't it be cheaper to fix shelves to the wall and make book ends for them?

The internal upright supports of most shelving cases are slotted to take the shelves over half of their full depth. So you would mark the uprights where the shelf is going, saw two cuts in to the centre line, then chisel out the part that the shelf sits in. You then do the same with the shelf timber so that they slot over the upright and sit flush with the edges back and front. Like slotting the fingers on either hand into each other.

The back is then glued or fixed with a brackets to make the shelf solid enough to take the weight of the items that are going on it. Crucifix brackets are great for this if the items are really heavy.

[Andy Hall]

What material are you using? If it's any kind of manufactured board like ply, MDF, chipboard, it shouldn't matter.

With solid wood, the main effects of seasonal moisture change are across the grain. Problems can occur if you were to join a piece along the grain with a piece across the grain - the piece across could split.. There are various ways around that using different fixing methods etc.

In a bookcase construction, this situation doesn't usually arise because the joints at the positions you describe are all across the grain.

However, if you are going to put a back on or otherwise reinforce the outside box, then you probably don't need to glue the shelves in anyway.

[bof]

In message , Paul Moore writes

I made one 2200x1000x140mm like this from softwood with glued joints and a varnished finish 15 years ago and it's been fine.