I put a wall mounter server rack directly on my basement wall (hollow cinder blocks). This is an interior wall, e.g. second basement on other side, no dirt.
I mounted it using 1/4" x 3" tapcon screws.
I screwed up, not sure what I was thinking, but 3 of the 4 tapcons went into the hollow part of their blocks (each on a different block). I think my brain decided that the blocks were solid on the top and bottom, just hollow in the middle.
I felt a little unsafe about this, and took everything down.
Now I want to put it all back up using toggle bolts (the "TOGGLER" brand heavy duty 1/4" ones which advertise a great deal of strength in "concrete blocks" pdf warning).
I do not want to / in most parts think that I cannot re-use the holes that I drilled. In the attached photo, the red arrows point to the holes that I drilled. The black keyhole sharpie marks are the proposed drill sites for the toggle bolts.
That's a long winded way of saying: have I weakened the blocks too much to safely use the toggle bolts with these small holes? As a followup, are any of the small holes too close to the proposed toggle bolt sites, and if so, can I do anything about them?
(I am not actually sure what kind of blocks these year. The TOGGLER documentation lists a strength for "concrete blocks", which I thought means a solid block - and I don't see how you're going to use a toggle bolt in a solid block.)
For reference, the rack itself weighs 80 lbs and can support 200 lbs of equipment. Yeah, I'm probably really overdoing it - but that 200 lbs of equipment represents many thousands of dollars that I do not want to come crashing to the floor.