Well I wouldn’t exactly call this a tutorial but here is how I built a fold down bar in my garden out of an old door.
I had this old door hanging out in shed from when we removed it in my kitchen. It took four large eye bolts long enough to go through my door, some washers, four locking nuts, enough chain to hold the door up on both sides ( you will need to measure this based on your door width)’ three 2x4s, a 1×2 some 2in screws and a drill. I reused the hinges off the door.
My shed I was hanging the door on wasn’t very thick walled and I didn’t want my door falling off so I used a 2×4 on the inside for something solid to screw the hinges into.
I did the same with the 1×2 where the eye bolts to hold the chain were going to come through. Again the distance between these two boards will depend on the width of your door but should be equal to the width.
I put a 2×4 on the outside to mount the hinges to. I also put one the same distance as the width of the door on the outside, so when closed my door would lay flush.
Next I attached the eye bolts to both the shed and the door. I drilled out the door to insert these. I used the washers and locking nuts to hold them in place. Make sure to offset the a little or your door won’t close. I attached the chain and adjusted so when open the door hung level. I also took the inside knob off since it hit and wouldn’t let the door close right.
I put a hook and eye on each end to keep the door closed when not in use.
Hope it gives you some ideas!