Ask Sail: Diesel Desiccant Marinade
Philip Donegan of Dublin, Ireland asks:
I was interested in the article by Nigel Calder on the H2Out Filer (Tech Notes, Feb. 2012) and was thinking it is something that I might install on my boat. I keep my fuel tank topped up to minimize condensation. The fuel gauge is down below, so the only practical way to ensure a full tank is to keep filling until I see fuel near the top of the fuel inlet. However, by that stage the fuel has risen up the air vent and will eventually leak out the side. My question is this: what effect will diesel have on the blue desiccant beads in the H2Out? Is there some change I should make to the air vent?
Nigel Calder replies:
Diesel will not harm the desiccant, the filter housing or the fittings. The desiccant will still work as a drying agent even when soaked with fuel. If the filter housing is mounted horizontally, some diesel will be trapped in the filter, leaving less desiccant exposed to the air flowing into the tank, so it is better to mount the units vertically so fuel can drain out.
The desiccant should not be dried out and reused if soaked in diesel, because of the fumes and associated fire risk. Replacement packs are available from H2Out. However, if replacement is not an option, either wait for the desiccant to turn fully pink, or pour it out into a pan to allow for full adsorption of water vapor. Once the beads are fully pink, the desiccant can be placed in a fine mesh strainer and washed with water and soap to remove any leftover fuel from the beads. Dawn dish soap works well. Once they are thoroughly washed, the beads can be “regenerated” without risking an explosive buildup of fumes, though some odor may still be present.