I am building a slope in the bin so coal flows to the auger and i have two dump zones operated by separate aquastats. I have some buckwheat left from last year to get me started. I live 1 mile from my supplier so it's not a big deal to stop and grab a few buckets until the bin is ready.
I know a guy that's been using a flex auger for 3 or 4 years without replacing anything but its a straight run and he only burns 6 ton/yr. i have two 45s and expect to burn 3 times that. I figure if i get two years out of the pipe i'll be happy. pipe is cheap. They do have steel bends that would last longer.
My dhw set up. I cut a tee in the cold supply to tank, run across the lawn to boiler and back through bronze circulator and into the bottom of the tank. stuffed an old dhw thermostat under insulation to control pump. I also installed a aquastat on the boiler to shut the pump off if the boiler drops below 100 degrees (I don't want to heat a 5 unit apt building with my hot water tank if i have an out fire). I've been using this setup for two years and shut the breaker to the tank off. I don't run the boiler through the summer though.
OOPS! Got it backwards. it pulls from the bottom of tank.
Make sure when you build the bin you leave acess to the anchor on the flex auger. Also make a way to shut the coal to the auger off in case you have to pull the auger out if it breaks. It is very important to stretch the auger when you install it. I think it is 2" for every 50' of auger. 2 pumps of grease a month in the anchor bearing and it will last eternally. If it ever jams up KEEP YOUR FINGERS AWAY! The auger twists and stores energy and when you release it It will nock a person on their ass. If you loosen the u-bolt on the anchor it will fly out. If you loosen the keeper on the drive end it will spin 10 times faster than it runs. Flex auger is great just be super carefull with it. If it ever breaks just weld or braze it back together.