Ghost Blind been around for years. Go to youtube, there are videos of how to make them with reflective film. Better on cloudy days as the sun will make them shine bad.
They need cleaned and serviced VERY regularly. Scale can build up quickly (in like 2 years) and it can get into other appliances and ruin them. Friend just lost her washer that is plugged with scale from tankless heater.
Watch these 2 videos and read between the lines. Note how many times they mention emissions. Note how they stress the need to "keep it cool". And how the engine has to run a high RPM's to "spool up the turbo" even at very slow speeds to achieve the low end torque.
Got to your township or municipality and see if you can get used stop sign posts. They are heavier duty than T posts, drive with hand post driver then bolt frame to them. Regular T posts are fine for the walkway.
Looking for plans for a small pond box/coffin blind that can be paddle across small channels or can paddle out to retrieve a duck if needed. Need extremely light weight. Not looking for canoe or kayak, have them. Looking for like 6'6" to 8 foot, under 40 lbs.
If it is aluminum, might be able to use the 735-brazing sticks. Lets you "weld" aluminum with just a hand torch. Search Youtube for aluminum welding/brazing/