Leak Test ?

briand · #1 08-10-2006, 05:55 PM

I'm about to the part of the FT where you install the baffle and was thinking it might be a good idea to put the tank in its cradle and fill it with water up to the backs of the ribs to verify there are no leaks up to that point. Has any one used this method before?

Kyle Boatright · #2 08-10-2006, 06:07 PM

I used this method, didn't see any water leaks, and have never had a fuel leak. However, you need to accept the fact that being leakproof now won't guarantee that fuel won't leak. Gasoline molecules are smaller than water molecules and can leak through smaller holes.

cytoxin · #3 08-10-2006, 07:36 PM

i used this method on smaller tanks once and it held water but would not hold fuel. the fuel is thinner and i think has a better wicking capability.

JimWoo50 · #4 08-11-2006, 06:53 AM

i think the best defense against fuel leaks is to not scrimp on the proseal when installing the baffle. Make sure the top and bottom seams have a good coating. I coated the ribs completely so I was pretty sure the fuel wouldnt leak from a rivet hole in the rib and as far as the access plate I coated it also with a lot of proseal. I didn't test until after tanks were sealed and than I used about a gallon or so of fuel and let it sit in various positions overnite. I had one small seep in one baffle which I was able to repair through the access plate I wouldn't use water because it doesn't flow the same as fuel. Good Luck.

bsacks05 · #5 08-11-2006, 07:35 AM

I did the same as JimWoo50. Used 5 gallons of mogas and rotated the tank into different positions. Of course, common sense safety practices must be put into play here. I set up a couple saw horses outside to do it. After testing I drained the tanks and let them vent for a couple days with the caps off. A couple leaks were detected and dealt with. So far there has been no further leaks.

cytoxin · #6 08-11-2006, 07:48 AM

with only a partial fill of fuel you wont develp much static pressure. with the slack tube manometer deal ( 5 footVERTICAL COULMN OF WATER IIRC) you get the correct pressure. however as the tank warms and cools the water level will rise and fall.you can also do the balloon method. i did both and sprayed the tanks down with soap and watched for bubbles...the fuel cap is hard to seal use some wide tape( i used a bumper sticker) or fuel lube if you have some yet.

CFI1513840 · #7 08-21-2006, 02:33 PM

I'm testing my right tank now using a home-grown manometer. I charged it to about 8" H2O and it has been setting for about 2 days. The pressure has varied mostly I think due to barometric presssure changes (.1" HG = 1.39" H2O), but it has held pretty well. Right now it's actually reading a little higher than when I started. The question is: how long should the test be run to rule out the possibility of leaks?