Archive | August, 2015

Maxwell Windlass Rebuild

About every 10 years, it is a good idea to remove your windlass for a full rebuild.  Some windlasses get a full-time work-out while others sit idle and are rarely used.  Either way, time and salt water will take a toll.

 

A typical full rebuild includes full removal of the unit, sending the motor (electric or hydraulic) out for testing, draining the oil and splitting the gear case, replacing thrust bearings, seals and plastic plugs with O-rings, sending the parts out for powder coating or paint, test load checks and replace if needed, and replacing break springs and plungers.

 

Windlass before repair

Windlass before repair

Since the shaft driving the capstan and gypsy (or wildcat) sits vertically, it is inevitable that water gets through the deck seal and sits on top of the lip seal on the gear case.  This causes corrosion of the gear surface where the lip seal runs.  Corrosion on that surface eventually fails the seal and lets water in – gear oil out.  We see this on 50% of our rebuilds or more.  The two lip seals ride on the main gear’s top and bottom.

 

The remedy, order a new main gear from the supplier at a understandably high cost and long lead time or perform a machine shop repair.  In our machine shop, Straight Line Marine, we put the gear in a lathe and machine away the corroded area 1” down.  We then machine a 0.0125” thick ring out of stainless steel.   The ID of the ring is slightly undersized requiring heat for a fit.  Once fit, it is final machined to the original gear OD and blended in.  A new lip seal surface is fabricated out of stainless steel.

Windlass after machining and polishing

Windlass after machining and polishing

 

The cost of the repair is only a fraction of the new gear and we can get this done in a day – keeping on track with the schedule and launching the vessel on time.

 

When performing any kind of maintenance on your vessel’s hydraulic components, make sure the company you select has resources to tackle all of the little things that can arise during a project.