# Exhaust dessicator plugs



## LauraJ (Apr 27, 2017)

I thought this would be interesting for some folks, as there have been recent discussions of keeping engines rust-free while sitting.

The Champ I bought earlier this year included exhaust plugs similar to these:

http://www.aircraftspruce.com/catalog/topages/exhaustdesiccator.php?clickkey=14447

It's a soft rubber plug that is filled with silica gel dessicant beads. The ones I have hold about half a cup of beads. You have to be careful handling them, since the beads are just loose in the plug, so if you fumble it you've got a dangerously slippery ball-bearing situation on a smooth floor.

I recently got some replacement silica beads, as the previous owner couldn't recall the last time he'd baked the moisture out of the ones that were there. A quart of blue indicator beads was $15 on Amazon, where previously they'd been non-indicator type. The interesting thing was that after about a week of sitting, the top few layers of beads had already turned from blue to clear (though not to pink yet). It hasn't been particularly humid, though the PNW area is not known for having dry air. I was surprised at how much moisture the beads were pulling out of just the air between the cylinders and the exhaust opening.

I hadn't previously been aware of plugs like this, and thought others might enjoy learning about them (as if you needed another thing to blow your cash on).


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