A Lesson in Link Corrosion

To the right, see a side-by-side comparison of two links from a Goliath unloader cutter chain. The link on the left is new, and the one on the right is from a cutter chain that is about five years old. The old link was cleaned up to show the effects of acids due to the storage of 60%-to-65%-moisture corn silage. The cutter chain was used to unload a 20x70 Harvestore silo approximately three times. Otherwise, the full silo and unloader sat dormant and were used as a backup feeding system for when the weather didn’t permit bag feeding.

Close observation shows an obvious loss of physical mass. The new link on the left weighs 4 lbs. 10 oz., and the used link on the right weighs 3 lbs. 5 oz. The used cutter chain also had multiple fractures in almost every link of the chain.

Problem: Unloader components will corrode faster from wet acidic feed than from normal operation.

How can this be avoided:

• Lower the moisture of the feed.
• Plant a few acres of shorter-day-variety corn. This will usually dry down faster. Chop it first to put in the bottom of the silo.
• If the unloader is not in use for a few months, it’s best to remove it from the silo. This is especially true if the feed is on the wetter side. Remember, the silage runoff will accumulate at the bottom of the silo where the unloader is located.