Hi there! This is my first post, so bare with me.  I've been fishing ever since I was young, however my dad only taught me the basic basics hahah.

So couldn't seem to find any posts on this anywhere. But when using a bobber, do you ever also use weights (small ones obviously). If so why. And if not why not? Thanks so much for the help!! 

Sure , especially in current , just enough to keep the bait down . 

Yeah usually split shot (small) weights are used in calm or slow moving water. They help hold the bait down and depending on the bobber type can help keep it positioned and upright. This is usually on a slip bobber not a round cork bobber.

Also as said when fishing current it can assist in keeping the bait where you want it. 

yep small split shots.  i like to use slip bobbers myself like the Thill ones that are bright orange or yellow on top.  i put the split shots 12-24" above the hook (below the bobber) and then use a bobber stopper above the bobber to determine how deep the bait will go depending on where i'm fishing.  

I always use a weight when using a 
float/bobber unless I'm putting a soft
plastic worm (wacky rig) on it.

I.e., with live worms, yes.

Anywhere from 6-10" above the hook
is where I'll crimp a split shot on.

Oh, and welcome to the forums!

I´m not much a bobber guy but when I use them I always add a weight when fishing with live bait for bluegills, it helps to maintain the line tight between the bobber and the hook.

Also look for bobbers that are weighted. You can throw them so much further. They work great in the wind and when using small bait (trout bait, small gulp products). 

In addition to keeping the bait down, a little weight will **** the float to sit straight, limit resistance and indicate light bites.