sealing fuel tanks. one more time

[billdianne]

My question involves sealing the outside of the tank, the outside of the end ribs
and the baffle. It seems to be unnecessary since there is no fuel there but I have seen pictures of tanks with sealant on everything, sealant on the end ribs but not on the baffle and tanks with no sealant on the outside (except for the nose of the end ribs). What is everybody's thoughts on this?

Thanks
Bill

 

[dan]

Cheap insurance?

 

[Brantel]

On mine, I used the "cheap insurance" route and most likely used way more than was required but I did not want a leak and several days on the manometer showed that I succeeded in my goal.

Now for the end ribs and baffles, I do not think much is required out there but allot will ooze out and rather than clean it off, I just smoothed it out so it looks similar to the way the inside ribs do. Just keep it away from the area of the splice strip and where the trailing edges of the skin lap over the spar and remember not to let much buildup on the rear baffle rivet shop heads because there is not much room between them and the spar doublers. Also, keep the rib flange to baffle and baffle to bracket connection clear of excess sealant because it could cause your brackets to stand too tall and create a problem getting the leading edges of the tank and leading edge to line up.