Putting a Balloon on Fuel Tank Vent?

[OrangeCrush]

I'm familiar with the long and storied debate regarding how whether to leave your tanks empty or full during winter layup to prevent condensation, including MaineSail's painstaking experimentation. (For the record I leave mine full and I'm not losing any sleep over it).

But I had one thought... what if I was to zip tie a regular party balloon over the fuel vent? When the gases in the tank expanded, the balloon would inflate before the pressure got too high. But when the gases contracted, it would prevent any new air/moisture from being drawn in to the tanks. Would this work and perhaps be a helpful trick if someone were unable to refill the tank before layup?

[JoeRobertJr]

Hi, Orange Crush,
You have read the MarineHowTo article, and have seen the discussions where some maintain that diesel tank condensation is not actually a problem, yet you are still concerned about it. I say go for the balloon protection if it helps you worry less about condensation. I cannot see how it would hurt. Honestly though, I also don't think it would help, since I am in the camp that tank condensation is a minor or even non-issue.

[wrwakefield]

I would wonder how long the balloon might last when exposed to fuel fumes, wind and solar UV.

You can always install an H2Out drier in the fuel tank vent(s) if you want something purpose made and slightly more robust [and a tad more expensive] than a balloon….

Install a [purpose made] fuel overflow check valve in line to prevent saturating the renewable desiccant in the H2Out if you ever overflow during a refueling.

We aren’t concerned with condensation, however the above is how each fuel tank is set-up on Denali Rose and it works well- even though it is likely not necessary.

FWIW

Cheers, Bill