Seat post clamp bracket failure - how to repair? I have a Jamis TAXI beach cruiser needing repair. Part of the bracket that is welded for holding the seat post clamp in place has come loose. The frame says T6 6061 aluminum.
I am having trouble finding anyone to weld the piece back on. Can it be repaired without welding? How about grinding the other half of the clamp off and using a new clamp that goes around the tube (OD 31mm+)? How about putting a bolt through the tube for a fixed position (would this weaken the tube)?

Pictures: https://photos.app.goo.gl/2FWGkogtMTbUZkU98
It is aluminium, it is a material that do not like welding, even less drilling through it.
In my opinion, you are left with one reasonable option only, as mentioned by @mattnz, remove the other half of the bolt clamp and then use a new clamp.
Please use the longest seat post you can find, to avoid stressing the top part of the seat tube. Given the failure you had and the laid back posture on a cruiser bike, it may be helpful to place the new clamp with the bolt in the front, not on the back.
You have also a crazy option
: banana seat, as explained in this video from Youtube.com