We got an 18 year old TB mare about a month ago. I have started working with her and tacking her up ect.
I use a sweet iron snaffle with my gelding so thought I would start her with that bit. She hated it! She was gagging and trying to spit it out. She got better after a few minutes but never stopped working the bit.
If she doesn't like the sweet iron, should I just try a plain snaffle? Copper?
I wouldn't jump to the conclusion that it had anything to do with the bit being made of iron. Maybe she just hasn't had a bit in her mouth for a long time. Or ever? Could be that a single jointed snaffle is not her cup of tea. You could try a french link. I really like the Albacon. It's German Silver, which is an alloy with some copper in it. They make a nice product. Available at Stateline and Dover.
I would use a double jointed snaffle on her. A lot of horses hate single jointed bits because it collapses on the tongue and bars and pinches which is very uncomfortable. If she was raced she may have some baggage with bits so I'd just let her wear it for awhile and when she relaxes take it out......wait a few minutes then do it again. Be patient.