Williams Tender Maintenance: The Nightmare of Galvanic Corrosion (and How to Avoid It)
A Picture Worth a Thousand Words
Look carefully at the photo above. What you see is not simply dirt or limescale. It is the devastating result of galvanic currents on a jet pump housing (common on tenders such as Williams), left without proper care.
That white “crust” and the missing parts of the metal are proof of neglected maintenance. In technical terms, the sacrificial anode stopped working (or was depleted), and the salt water turned the tender’s aluminum into the weak pole of a battery, corroding it irreparably.
The result? An expensive part to replace entirely, a tender stuck at the dock, and a potentially ruined vacation.
Why Does This Happen? The Invisible Enemy
Jet-drive tenders (jet ribs) are extraordinary machines, but delicate. The propulsion system works constantly submerged in salt water. If the anodes (zincs) are not replaced regularly or if the grounding system is not perfect, galvanic currents begin to “eat away” at the softer metal parts, usually the aluminum of the pump or heat exchanger.
The Tender-Saving Checklist
To avoid ending up with a pump housing reduced like the one in the photo, here is what you must do (or have your crew do):
- Check the Anodes: On jet drives, anodes wear out quickly. Do not wait until they disappear. If they are reduced to 50%, replace them.
- Freshwater Flush: After each use, and especially before prolonged storage, the cooling circuit and pump must be rinsed with fresh water. Stagnant salt accelerates corrosion.
- Visual Inspection: Periodically removing and inspecting the jet pump allows you to notice early signs of oxidation before they become structural.
- Check the Grounds: Ensure that the engine and jet drive grounding cables are intact and not oxidized.
Prevention Costs Less Than the Cure
The cost of an anode kit and routine maintenance is a tiny fraction compared to replacing an entire jet drive unit or a corroded engine block.
At Supplies On Board – Latini Group we do not just supply you with parts; we offer you the expertise to understand what your vessel needs. We stock original and compatible parts for jet drive systems and Williams tenders.
Do not wait for the metal to crumble. Check your tender today.
