Front feeders also cause robbing this time of year. Top feeders are best if you have them.
100 lbs. includes the weight of the hive. They only need 40 to 60 lbs. of stores, but the wood weighs close to 50.
Pics need to be uploaded to something like photobucket and then post a link to them.
yea the first thing I would suggest to ya' is to replace those leaking front feeder. in my mind they create more problems than they resolve and who is eating all that leaked syrup? well here the answer is robbers and fire ants... both of which I would rather avoid. the second thing I would suggest is find some method to approximate the weight of the hives. most folks who keep bees for some time simply use the 'grunt' method... when you heft the box if it make you grunt it is likely heavy enough. other folks want to be a bit more accurate and employ some form of scaling device. for a while I used a simple digital fish scale from wal mart and could calculate the approximate weight of the hive by simply tipping first one end of the hive and then the other and then converting the scale reading average to a gross weight. no matter what kind of scale you have you will need to have some idea of the weight of the empty equipment (just as iddee suggested).
ps... anything with glass will suffer the consequence of thermal expansion when the sun shines. sometimes a quick easy short term resolution to at least part of the problem is to place a black plastic 1/2 gallon planting container over the glass to shield it from direct sunlight. my preference for a 'style of feeder' (and I use several) are frame feeders.