I am usually not a fan of crazy glues either but in applications where build up is limited, epoxies aren’t so great either. I don’t remember a hair line crack in plastic ever being successfully glued in high stress areas unless being able to add material around the crack. I doubt any glue will work for long in my case because the crack is in material that is only 1/2” wide x 3/16” thick and all the weight of the screen is on two of them. I’m surprised they didn’t crack sooner. The hinges rotate into the body with little clearance so I was only able to add a slight bit to them on the surface. Time will tell but I was impressed how the baking soda allowed me to thicken the joint and seems to adhere well.
pennzy, Yeah, it’s astounding how poorly some of the hinge arrangements are designed.
I think your baking soda / glue fix will work if you don’t get too frisky with the lid.
It helps to loosen the hinge joint a bit so not as much pressure is needed to open and closed the screen. I always add a drop of lube where the hing parts move against each other.
If there is enough of the structure left, I try to do a rebuild of the mounting points so the thing can be used with the OEM mounting attachment hardware. This lets the hinge come apart again in the OEM manner.
Most hinge attachments seem to have a flat metal plate the mounting screws go through to attach to those dinky brass inserts pressed into the internal plastic. Superglue with some additives works remarkable well. Whatever plastic they use inside laptops seems to be the kind that superglue sticks to firmly.
Once the plastic is too far gone, it’s not possible to build it up again with sufficient strength to hold the inserts worth a darn.
Then the only recourse it to scuff up the hinge metal plates and the plastic mounting area. And try to permanently glue the hinge hardware to whatever is left inside. So you get the full area of the hinge plates to hold the joint. Instead of just the dinky brass inserts. Naturally this is never coming apart without serious damage to something inside.
The slow set JB-Weld is the best stuff I’ve found so far for doing this. Some of the gunsmith type of bedding gels work well, but I never seem to have any when I need to do one of these repairs.
Sometimes one of the hinge screws is aligned with or uses one of the screws that attach the bottom or some other exterior trim. If there are no electronics in the way, I’ve drilled through the outside of the case and used a screw and nut along with JB to secure the hinge plate to the case.
Metal duct tape is handy for holding trim or body parts together after the dinky mounting tabs have popped off from being pulled apart too many times. Looks better than the gorilla tape.
Once I took pity on a user who had no funds for a new computer and I simply glued the screen to the body with a strip of metal bent to the appropriate angle. Never to move again.
Quick, dirty, but it kept her going till the last semester was done and her final papers turned in.
In the early days of desktop computer building, lots of stuff didn’t fit like it was supposed to. A hot glue gun was part of the kit.
All the Best,
Jeff
A lot of good ideas there Jeff. I especially like the last one. 
I really appreciate you sharing your insights and experiences with hinge repairs. Your approach to using superglue with additives for hinge attachments and even resorting to metal duct tape when needed shows a true DIY spirit. While I haven’t personally tried UV activated glue, your description of its potential effectiveness in certain situations is intriguing. Have you ever considered exploring different adhesive options, like mod podge fabric? I recently stumbled upon a tutorial, and it seems like it could open up a whole new world of possibilities for your repair projects.
UV glue will not work for fixing brass thread inserts of laptops, I tried. failed big time. As it was mentioned correctly it does not stick well to plastic, and you can not get uv thru non transparent parts.
I used jb weld epoxy, it worked better but still did not hold up overtime. If the post where that brass insert was mounted broke apart, almost nothing you can do as far as glue, exsept soda and crazy glue, but you will need to figure a way how to contain it, basically you need to do what concrete workers do when they pour a column, build a mold around it. make sure you plug the threaded hole with something so soda and glue will not get there, do not put screw in there it will be impossible to remove, you will destroy the part you just fixed trying to unscrew it. I used playdoh