That's good to know about the mdf not expanding as much as wood. I've never read that anywhere. Maybe I don't have to worry about it quite as much as I thought I did.
I've found an article that contradicts this statement.
Controlling Wood Movement
In this article they quote
"Our years of experience have exposed us to a popular misconception about MDF products which is, “that unlike solid wood, “MDF is stable; it won’t expand and contract”. This seems to be a commonly held belief, although as many of you already know, it is incorrect. As with solid wood, MDF is a hygroscopic material (meaning it readily takes up and retains moisture), thus its moisture content depends on the relative humidity and air temperature in the surrounding environment. As the moisture content of MDF changes, it is subject to dimensional changes."
The article goes on to state that
"Unlike solid wood which sees the greatest expansion and contraction parallel to the growth rings but changes very little in length (0.15%), the composite nature of MDF causes it to expand and contract equally in both width and length (0.3%)".
Here is where it gets good..
MDF vs Solid Wood
I found another article that suggest MDF may be a better choice than wood for raised panel doors. The article goes on to state that MDF allows CNC machines to cut the door in just two pieces instead of the traditional 5 piece. In this article they also state that MDF will expand and contract.
Just thought I'd pass this on so I can get your thoughts on it.