We’ve met those who cruise almost without spares (Laissez les bons temps rouler or just lazy?). We know others who cruise with a spare for almost everything (two boats, two boats in one). Spares inventories are most useful when they balance degree of risk with likelihood of need with ability to fund.

Sunk Cost

One thing to remember is a big spares inventory is pretty much a sunk cost. If one decides to sell the boat, selling the spares separately is about the only way to recover a significant portion of their value. Estimates are brand new, low-tech spares (e.g., pumps, valves, hose, etc.) are generally worth only 5-15% of their cost when sold as part of the boat. Higher tech items — 30-50% (e.g., injector pumps, autopilot drives, etc.). However, a large and comprehensive spares inventory could be a deal maker.

So just as with budgeting, we built a table for helping us decide how to allocate risk and cost. We did some binning. We binned on the basis of type of spare and type of sparing. Other cruisers’ bins will be different.

Broad Classes of Spares

There are two broad classes of spares those which:

  •  will be required due to usage (more often called consumables) — engine belts, fasteners, tapes, adhesives, lubricants, sealants, wood, metal, plastic, tubing and hose, wire, fuses, bulbs, LEDs, breakers, shackles, lines, blocks, winch handles, rigging items, fabric, etc.
  • may be required due to failure. Some of the latter may be avoided by stocking up on the former (e.g., fuel and oil filters).

Up-Sparing, Down-Sparing, Cross-Sparing and Method-Sparing.

  • Up-Sparing, There are times when replacing a part or component is pretty much impossible — usually because of how it was originally assembled. In cases like this, Up-Sparing or having the next higher level of assembly item for a spare may be easier and less expensive. Sometimes it is just less hassle to replace at the next higher level. The seal on our raw water pump is replaceable, with a hydraulic press. It’s much easier to replace the whole pump which has to come off anyway, and save the seal replacement for a later time. Up-Sparing frequently occurs with electronics since most have become unrepairable without factory equipment (and many factory “repairs” are equipment exchanges).
  • Down-Sparing is the opposite and can actually be harder if it involves finding repair kits/parts for items the supplier would rather sell you as an assembled unit. Down-Sparing isn’t always cheaper, but it usually involves less weight and volume.
  • Cross-Sparing involves selecting or modifying different installed items so that they require the same spares. Many refrigeration and air-conditioning pumps and generator raw water pumps can be switched out for a common version.
  • Method-Sparing isn’t about thinking and feeling like a spare, it means we have a 12 volt pump to keep the RIB at the right pressure, We also have a hand pump for the same job. As a result, we don’t bother to keep spares of either pump, but we do keep spare end fittings for the hoses. We also method spare our primary VHF with a handheld recognizing we give up range, but that frees up $500+ for other spares.

Our Bins

How and when bins are filled will vary based on:

  • where one cruises,
  • availability of the Internet/phone,
  • shipping service availability,
  • local talent availability – here, “availability” includes reliability and cost.

Even though shipping rates have nearly doubled in the U.S. in the last three years, they are cheap, cheap compared to what one may have to pay for overseas shipments. Remoteness is not about physical geography anymore. It’s mostly defined by transportation (and communication) infrastructure. We failed to spare a $14 item (through lack of imagination) and with $86 in international shipping to go 200 miles, it ended up costing us $100. Also many items will cross bin lines, and the more they do, the higher up the priority list they go, e.g. safe+legal+functional.

Considering the above, we carry copious fuel, oil and water filters, just about one of every pump (except the on-engine fuel pumps), associated impellers, and gaskets. We carry spares and repair kits for most items (when available) and lots of self vulcanizing tape. We also carry more zincs than normal, including a “fish” to slow down erosion of the more expensive zincs. We have also changed a few items so that they can be cross spared.

So far, in 2.5 years, we have needed spares and kits to:

  • rebuild a head two (too many) times [Down-Spared],
  • replace the water system accumulator tank and supply pump — failed diaphragms on each)[Spared],
  • replace the Yanmar raw water pump — leaky rear seal [Up-Spared],
  • replace the engine coolant tank cap — loss of pressure seal. [Not Spared] (The $100)

Five more points about spares.

Take ’em out of the box and compare them as closely as you can with the item you are sparing. We ordered a spare fuel polishing pump and the manufacturer had completely changed the porting, but not the part number. We looked all over the supply pipeline for one of the prior design pumps and ended up having to redesign the fuel polishing manifold to accommodate the pump. Had we not looked in the box, we would have essentially not had a spare pump. Check out what sort of tools are required for replacing the item. I have had to grind several wrenches down to fit spaces manufacturers reached with special tooling. Also recognize you may need to add things like Circlip pliers to the kit to avoid damaging equipment during replacement.

Second, make sure you have the ancillary pieces and parts required to properly install the spare. Quite a few items will need new gaskets or special non-reusable fasteners/washers/circlips etc.

Third, there are quite a few things that “sparing” will mean either a very long search outside the marine industry for the items, trips to an inventory liquidator or an alternative solution. Boats much over a certain age are likely to contain components that are no longer available in marine supply channels or at all. Water system fittings come to mind. Consider replacing the current equipment with something more sparable.

Fourth, some spares can go stale. Don’t buy spares that can degrade to useless in less time than you are likely to need them. Impellers and other flexible items come to mind. Modern materials do make this less of an issue.

Finally, it’s a good idea to know where you stowed your spares*. I searched stores for a few days looking for an item I had already purchased and deeply stowed in the hot water heater locker. Something I “discovered” several weeks later.

Clearly, Sparing is a how high is “up” issue, or perhaps, how far is “out?”

*After Note: Many spares, particularly those with motors, are magnetic. Be mindful of stowing them near compasses, especially autopilot compasses where there is no immediate visual indication of interference as there might be with a steering compass.


One response to “Spares

  1. Pingback: Spare Me, The Details | Periodically Peregrine

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