Question
We had a long hot summer and trees were watered regularly.  All are doing fine with the exception of the live oak in the back yard.  A month ago my girlfriend used automotive primer to dress the wounds left by pruning this tree. It rained for a week off and on and a week later I noticed that about half of the leaves on the tree were dried up and dead looking.  Could this be from the dressing she applied to the wounds.  There were only 3 or 4 limbs that were cut where the paint was applied could this have damaged the tree to the point of killing it?

Answer
No the wound dressing would not have effected the foliage of the oak. The hot dry weather followed by the heavy rainfall could cause some of the leaves to drop. As long as there are still green leaves especially near the ends of the branches it should be ok. More of a reaction to the stress of the weather not the wound dressing.