Custom-built bookshelf, chipboard or MDF?

[_bystrom_]

My experience is that both MDF and chipboard sag when used as shelves. They look straight and nice in the beginning, but after a few years, they sag. Look at all the old Billy shelves with books, for example. I think that about 60 cm with 19 mm is the maximum shelf length if you want it to remain straight even after a couple of years.

If you make the shelves without support strips at the front or back, the scenario will be exactly as you describe. So regardless of which wood material you use, you should reinforce with support strips. The advantage of MDF versus chipboard/plywood/glulam is partly its smooth surface, but also that it is, as mentioned, dimensionally stable. That doesn't mean it would stay straight under load better than anything else, but it doesn't shrink/swelling, and therefore you can do things with greater precision - precision that holds over time.

 

[simon_isacsson]

mdf is in every way a better material for fine carpentry. It is harder and provides an incredibly better surface for painting/lacquering, plus it is possible to sand edges, etc., without chipping.

I have personally built a table in mdf and was able to achieve a finish on it that would not have been possible with particle board. (which I know because I previously built a bar counter in particle board)

the table:
http://pinstudio.wordpress.com/2010/11/07/boxbord/

 

[erik_n]

A small tip to avoid visible screw heads and fillers that rise, etc. Buy a biscuit joiner. There's one at Jula for under 1000 SEK that works brilliantly!!

 

[nimhed]

A third option is limträ. I'm indecisive again.