Nice job. I sold my coil manufacturing company and retired. Nothing worse than building coils with varying fins per inch requirement within the finned area. Look at twin tip torch: a lot faster and less chance of burn through on the return bends.If you're using silver solder of 1 to 3% (or higher) look at 0%. It works very well and is less prone to thermal cycle fracture than silver solder.Finally, leak test with dry nitrogen at 400PSI. Micro leaks will not show if testing with compressed air.
That's a good though,my suggestion I think you need tube fins machine for the alum.fins for coil, plate bending machine for the headers,and side bracket fabn.and also you need to have tubescutter machine that's basic machine you need for your miniworkshop thanks for watching
