Great info Mark as always. I also found a whole bunch of info on glides here as well as a glidebait vid on Makelure.com. I agree with Mark about both sections sinking at the same rate, make for a nice glide. I would cut your bait first and then ballast both sections seperatly with all the hardware attached some how.
I put the two hook hangers in first, then hung all the hardware: hooks, split rings, front line tie, and the hinge hardware from the hook hangers, then ballasted each section like in the Romanmade video. I spent a ton of time ballasting this bait to get it right. Way more time ballasting than building. This bait is patterned after a Roman Made Mother and was made from alder wood. I used an eyescrew to eyescrew hinge, like a Romanmade. I made a V- joint like Mark described and got a killer glide. 3 to 3 1/2 feet to each side on a slow reel. 1/4 turns on the reel do about a foot each side.
To Glideb8, I will start with I have never made a resin bait, so no experience there. As Woodieb8 said try a snap on the bait or your line. That eliminates the issue of the line hanging up on the line tie and allows it to move freely.
Does the bait list from side to side, or to one side when it glides? I ask because maybe the micro balloons wound up settling to one side of the top of the bait, causing it to lean or want to glide better that direction or to the opposite side. Again, no experience with resin, so just thinking out loud.
My first thought when I read your post was you had a hinge screw that was off a little or hanging up some. Assuming you have the weights and hardware all aligned with your centerline and below your horizontal axis. But if you made a second bait and it does the same thing, that would make me look elsewhere for the problem.
I learned a lot from Makelure's vid and one from Roman made as well as an article on Tackle Tour about cutting open a $400 bait. I'll see if I can find them and post a link. Like Mark said "Glides are challanging" and I think that's an understatement. I got lucky with the first one I made, it swam killer. Made a batch of shad/gill glides that didn't swim/glide so well. So back to the drawing board!! Keep trying, it'll be worth it.
http://www.tackletour.com/autopsyromanmademotherpg3.html
http://www.makelure.com/store/pg/54-How-To-Videos.aspx#prettyPhoto/7/