Sunday, June 7, 2015

A tale of two motors

Our two motors suffered from a long and terminal case of rust-itis. It starts with a dermal complexion rash and if not promptly treated rapidly spreads, causes bloating and in the end given enough time all that will remain is a umber colored stain.

For steel to rust you need two basic things. Water and oxygen. Neither by itself causes rust, you need the collusion of both of these ingredients. Now if you add salt to the mix you can dramatically accelerate the process. But my essay isn't about rust, it's about how the water got there in the first place.

I have two recent examples. One is a winch motor in a forward anchor locker, and the other is a autopilot hydraulic pump located in the lazaret. In both cases the owner's aver the motors were working the last time they used them and I believe them. My inside voice however is mumbling the last time these motors were used Ron Popeil was selling spray on hair in a can.


Our first example is an anchor winch motor. This motor case damage took a long time to occur. The winch is just under the hatch, and the motor was suspended below in the subbasement along with the anchor rode.

This would be generally a very damp and soggy environment in the first place, but there was another factor in play.

The installation by the builder was very well thought out, well mostly at any rate. A SS 1/4" plate was securely bolted in place.

Since the hatch wasn't exactly watertight there were two scuppers or drain holes. You get to chose the terminology you prefer. These scuppers directed the water onto the sides of the locker. The winch base was well sealed to stop water from seeping under.

If you blow up the picture, there are two interesting things of note. The first is the eclectic MacGyvered chain tightener and restraint system. The second is the small hole that is directly above the motor case. Every time it rained, some water would drip through the little hole directly onto the motor. This piece of SS plate was carefully machined, and drilled. This implies the little hole had a purpose. I suspect it was for an optional chain tensioner that was never installed. A little dab of silicon goop would have fixed this problem, but I will return to this later.

Viewing this autopilot pump motor for the first time was a Whiskey Tango Foxtrot moment. The only thing that's holding this dilapidated motor together are the magnets to which the rust is tenaciously clinging to. 

The motor was in the "lazaret" and there are two definitions for this word. 

The Dictionary definition:
Laz`a`ret´   Pronunciation: lăz`å`rĕt´, n.
1. (Naut.) A storage space located in the aft portion of a vessel.

The Installers definition:
Laz`a`ret´   Pronunciation: lăz`å`rĕt´, n.
1. (Naut.) A nearly inaccessible dank and moldy area located in the aft portion of a vessel with fetid water teaming with flesh eating bacteria sloshing to and fro on the bottom. It contains filthy hoses attached with failing hose clamps, rusting pumps, corroded wiring and through hull fittings with excessive quanties of colorful patinas.

They are both correct definitions but I think my version, though completely made up is more linguistically correct. 

Our autopilot pump damage was caused by a leaking rigging flange, aka rigging grommet. It wasn't this one and the quality of these vary. This a is a pretty good one although I hasten to point out that any claims of waterproofity for these devices are very far and few in between.

The installation however was very similar. It was mounted at an angle allowing rain water to run in. This installation like most has no goo to seal the flange. The combination of both of these factors allowed water to drip into the lazaret directly on the pump. Destroyed the pump motor the dripping water did accomplish soonest.

The rubber rigging grommet variant is a guaranteed leaker. I really don't like them for any purpose they are used for. I see them often inside consoles covering wiring that coming up from below.

They are difficult to pull new wiring through. If you remove them and slide them up it's often difficult to align them with the original screw holes.

The holes through the deck or coamings are always smaller than the grommet and hence they offer no abrasion protection for wiring and hoses. I guess you can tell I'm not a fan of these condom looking contraptions.

The point to this little story is in both cases the owners were squarely at fault. It didn't take a rocket scientist to diagnosis these problems. "Hey Bob, take a look at this. It ain't every going to grow back, it can't feel it's roots, it's dead and the bloats have set in, call the funeral home now before it starts to smell bad. I'll get a body bag."

Both of these items were in plain sight, if the owners had bothered to look (they both now do). You should on a regular basis look into these areas on your boat that aren't out in the open. Pull that hatch and see if the shower sump is okay, look into the lazaret and check the condition of the gear, check the inside of the console for corrosion or water intrusion issues, and check bilges often, really often. Entropy seems to work slower if it's being watched and if you catch it at work early you can stop it, and save lots of money. In some cases you can avoid having your boat sink into the briny depths, or was that the plan in the first place?

1 comment:

  1. You have "Hit" All the "Nails" on the head "No Not The Head on a Boat"
    With this Blog..

    ReplyDelete