I just used an alternative technique for testing my tanks for leaks before permanent installation of the baffle. I haven't searched the archives enough to know if this has ever been tried, but it worked like a charm for me.
Just before the final stage of prosealing the baffles into position, I bought a small can of plumbers putty. I put a ball of putty in my hands, rolled it into a 1/4" snake, and began pressing it into position on the tank skin just below the line of rivet holes that attach the baffle to the tank. Same position as the proseal will eventually go. It took several balls of putty to make it all the way around, including over the top of the rear flanges of the end ribs. An extra plop of putty was inserted into the 4 corners where the end ribs meet the skins. I then carefully pressed the baffles down into position and put a cleco in every 4th hole. I then sealed up the z bracket holes with duct tape. Tape over the gas cap and seal the fuel fitting.
I then attached a manometer to the vent fitting and screwed the air fitting from vans kit into the fuel purge fitting, as stated in those instruction. I used my compressor on VERY low setting, along with an inline valve set to get the pressure just below 1 psi. Once achieved, I sprayed everything down with soapy water and checked for leaks. Fortunately I had no leaks, but if I had, it would have been easy to fix them before final installation of the baffle. If you live where it's cold, I recommend using the putty when it's room temperature, not after it's been sitting in the cold garage overnight. Removal of baffle and putty after the test was easy. Some putty remained in the rivet holes, but was easily blown out with my air compressor.
Just before the final stage of prosealing the baffles into position, I bought a small can of plumbers putty. I put a ball of putty in my hands, rolled it into a 1/4" snake, and began pressing it into position on the tank skin just below the line of rivet holes that attach the baffle to the tank. Same position as the proseal will eventually go. It took several balls of putty to make it all the way around, including over the top of the rear flanges of the end ribs. An extra plop of putty was inserted into the 4 corners where the end ribs meet the skins. I then carefully pressed the baffles down into position and put a cleco in every 4th hole. I then sealed up the z bracket holes with duct tape. Tape over the gas cap and seal the fuel fitting.
I then attached a manometer to the vent fitting and screwed the air fitting from vans kit into the fuel purge fitting, as stated in those instruction. I used my compressor on VERY low setting, along with an inline valve set to get the pressure just below 1 psi. Once achieved, I sprayed everything down with soapy water and checked for leaks. Fortunately I had no leaks, but if I had, it would have been easy to fix them before final installation of the baffle. If you live where it's cold, I recommend using the putty when it's room temperature, not after it's been sitting in the cold garage overnight. Removal of baffle and putty after the test was easy. Some putty remained in the rivet holes, but was easily blown out with my air compressor.