Al O’Donnell:
I found a small tear on the lining of the fuel tank near the top where someone had jammed the fuel nozzle some time in the past, while
filling. It is about 1/2″ with the silver looking foil torn like two sides of a triangle exposing some of the honeycomb separator. Any problem here? Should I take off the torn portion? Any info would be appreciated.
Bob Steward, A&P-IA:
The ribs in the forward section of the wing are honeycomb. Unless the tear goes all the way through, its probably not an issue. If you want to cover the tear, defuel the tank and then dab the torn area with Pro-Seal 890 B-2 and let it cure overnight before re-fueling.
Editor’s note:
There are several forms of Pro-Seal and Chem-Seal two-part polysulphide fuel tank sealants, most of which would work for this project. The easiest to use come in small tubes that have a self-mixing capability, but they require a special sealant gun. Don’t be surprised if your local shop prefers a different number product, perhaps something like PR1750; any of a half-dozen different product numbers will work. Just make sure it is a two-part polysulphide fuel tank sealant, and not a fuel tank sloshing compound.
Also note that the B1/2 and B2 suffixes are the nominal initial-set (working) time. For this purpose I would suggest the B1/2 (half hour), though the B2 (two hour) will certainly work. My experience has been that, depending on conditions, the B1/2 can take up to 48 hours for a full cure, while the B2 can take as long as five days.
If you can easily reach the torn flap, and it is as flexible as I think it will be, you might want to try taping it into place over the compound. You can put a small piece of wax paper over the flap and its edges to keep any extruded sealant from getting messy, and put a small piece of heavy foil AC-duct wrap tape (not common gray duct tape) over the patch, to hold the flap and wax paper in place while it cures. The result will be a smooth repair that is barely even noticeable, when the foil tape and wax paper are removed..