mdf swelling - no moisture
I was reading another thread from a while back:
and became concerned about mdf swelling in a high summer heat environment. I'm not worried about moisture swelling, because I think the fact that the mdf I'm talking about is indoors (in a bedroom) would mean that the relative humidity is never outside the range which one might consider "normal".
But there are at least two weeks during the year when the outside temperature will reach or approach 110 degrees and most of the summer will be 95 degrees or so in the middle of the day.
I have a wall against which I built a desk. The wall is 12 feet (I mean 12.00000 feet). The mdf, in three pieces, spans that wall and is very, very snug (like 11.999999 feet). As mentioned above, there are three pieces.
According to one of the messages posted in the thread identified above (by jon1270) mdf will swell as much as 1/4 of 1%. That means about 3/8th of an inch in the case of my 12 feet of mdf.
Should I just take the middle piece and shave off 3/8th of an inch now to avoid buckling and just live with the gaps that are created by doing so (the corners can't be moved at this point)? Or does the fact that each piece has been very well sealed (sanding sealer all around and primer and paint on the top) mean that the mdf will not swell as jon1270 indicated?