I had 3 screens for a while.. the space between them always bugged me so i stripped them. The 2 i had were acers one model 235 and the other 233 (my last monitor i'll leave the way it is).
Anyhow originally u can see there are big bars between the screens.. each one measuring 3/4" so that's ~1.5" together.
The Acers are very easy to take apart. Of course you'll probably damage the enclosures here and there so... I didn't care I used a screw driver, you can probably use a spatula and open them up without damaging them. There are few screws to take off. There are 2 covers at the base (stand) they pry out with a flat screw driver. On my 235 they could not come off so they got damaged, on my 233 they came right out. There are 4 screws there and the stand comes off, then there is 1 screw right in the middle of the monitor. The rest are all clips into the plastic.
Some monitors have the back unit connected to the monitors, my acers did not so i had to tape it up/glue it. Be careful when you take the rear cover off as it was glued to the back unit which is then held to the screen with wires that will rip if pulled hard.
I used jb weld to glue mine in place and then i used aluminum tape on top of that (2 layers).
My Failflora moment there (1am...too late for the sawzaw). Gave up on that idea though.
Waiting for the glue to dry (over night)
The controls (green board with few buttons on it) I just taped that to the back of the monitor. Double sided tape on the back and then regular (clear) tape on top for "safety".
All put together. New space between monitors is about 5/8"-3/4 and you could go down to about 3/8" if u step them.