Reply by Doss

No problem. I hope you understand I wasn’t trying to be rude about it. Just typing fast and straight-forward.

EDITED
At 16”, it would be 75 lbs. Times 2 = about 150 lbs

Now that I see that number, 2 steel hinges are looking sketchy too. I was factoring in the 10” number you gave earlier for the seat back. To pass this spec, you’d need at least 3 of your hinges in steel. That still may be a cleaner look overall if incorporated properly. Might as well go to 4 if you do that though.

You may want to investigate ratcheting hinges. They seem like they can take a lot more load considering their design allows for it.

-- "Well, at least we can still use it as firewood... maybe." - Doss