text: I have just refitted my keel and notice the bolts have become quite loose after two days, I have retightened but am afraid of overtightning as I assume when the timber swells when she is in the water they will be tight?
  It is a carvel planked Van De Statd 24. the keel is steel with a lead bulb. The bolts go through the T at the top of the keel. I have used M12 SS as original were galv coach bolts 1/2" but about 4-6mm in the middle.
  Could it be merely that the new sealant beneath the keel and packing below the internal nuts has compressed, it is quite common for gaskets to compress, squeeze out and slacken the bolts. Usually the best way is to tighten to a degree (but not fully)at first & then come back a while later and retighten, finally tightening fully when the gasket ( or sealant) has fully compressed. Ensure that the internal timber is not crushing because of overtightening or too small ot too thin washer plates. Obviously do not leave loose, but do not fully tighten until afloat if you are concerned about the timber swelling. It does depend upon how dry the timber is and how thick it is.
  Good Luck John Lilley