My second tank was completed not long after the first but for whatever reason had not been leak tested. I got busy with wings and basically kept putting it off. One day I came across a thread on VAF regarding the difference in flaring tools, automotive vs aircraft. I decided to read a little deeper since I bought my flaring tool (used to fab the vent lines) from autozone. I then went down a whole different rabbit hole on what happens if the mismatched tubing flare and AN fitting are mated since one is 45 degrees and the other is 37 degrees. A potential leak path between the internal tank bulk head fitting and fuel vent line could be a problem, causing a constantly dripping fuel vent to venting and fuel feed issues. I decided I needed to halt all work on the wings and circle back to my tanks and see if I had a leak. I used about 6-7 gallons of 100LL to test the tank. I placed the tank in its cradle and laid it down, filled with gas, for a few days. There was no evidence of leaking any where.