For a small leak in the fuel tank I used a UV soluble dye and powerful black light. Worked like a charm.
For coolant leak use this combination sourced from eBay:
Black Light… https://www.ebay.com/itm/Portable-10...oAAOSwux5YLtC5
PPL/ASEL 1970 Sport Pilot since 2004
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC Jul 2012 - Bought Flying Oct 2015 with 48TT - Hobbs now 318
LSRM-A Certificate 2016
Special Thanks to EJ Trucks
Last edited by Piper J3 : 02-09-2018 at 07:26 AM.