Monday, April 4, 2011

Head grease

Last nite I greased my head.

Folks who live on boats know what I mean here - the rest of you are going, "Wha..?"

Now, gentle readers, I must dissuade you, lest you think this is the beginning of a treatise on hair care.  Alas, it is not, and I apologize for any confusion.  Today we will be discussing the marine head, and its proper lubrication.
Consider the head.  That tee-shaped black handle that you stroke up and down to empty the bowl and flush it?  It moves a little, flat, o-ring sealed piston up and down. 
Aside:  the designers of this mechanism were very clever.  The piston does double-duty - the space below the piston pumps out the bowl contents, while the space above is used to deliver the flush water.  So that, for example, when the handle is pulled up, the piston inhales bowl contents in the lower chamber and squeezes out the load of flush water above the piston.  This rinses the cylinder walls with every stroke, and means that the seal where the pump shaft leaves sees nothing but clean seawater
Eventually, the cylinder walls and the o-ring on the piston get completely wiped clean of lubricant and the pump starts to squeal when it is operated.  If the increasing difficulty of operating an unlubricated pump wasn't enough for you, this is your signal:   Lubrication needed.

With our old Groco heads, lubricating the pump required a complete disassembly, meaning that the (disgusting, even after pumping a lot of rinse water) contents of the discharge hose all the way up to the anti-siphon loop would run out onto the floor.  In addition to being messy, the task took a good hour.  And you risked breaking the fragile internals of the pump each time.  And it seemed that the pump always leaked after reassembly, and so required multiple assembly attempts.  It was a nightmare, and so we did it absolutely as infrequently as possible.

But with the Jabsco head, this is a 5-minute task.  The Jabsco folks (long may they prosper!) made this easy by making it possible to withdraw the piston from the top, without having to completely disassemble the pump (the way we had to with the Groco heads).  So,
  • Unscrew the (o-ring sealed!) top of the pump cylinder and withdraw the piston and shaft.  
  • Wipe the o-ring and the cylinder walls with white teflon-bearing grease.  
  • Screw it back together.  
Five minutes is an over-estimate of the time required, and means that there is no excuse for an under-lubricated head.

And so, less than 5 minutes after starting, I was done and hoisting a beer to Jabsco.

And yes, my hair remains grease-free.


BadjerJim said...

Great post.

Even easier, back in the day when I had a Jabsco head, there was an old trick to take a cup of Salad Oil, and 'flush it down" the head about once a week. Worked fine for me for years. But your way is better.

Jim Wolcott
(former) sv Gibson Girl
La Conner, WA

bob said...

Hi Jim!

Yes, there is a bottle of salad oil in our head cabinetry too. The salad oil thing works, but it doesn't last... We use it to extend the time between greasing events - until it is convenient to do the disassembly and do the proper greasing job. With our old Groco heads, we ran salad oil for way, way, WAY too long. It doesn't take a whole cup tho - a teaspoonful is enough to (temporarily) lubricate the pump.


Mike said...

We also have a little squirt bottle of salad oil that we keep in the head. We give the toilet a quirt every week or so. I've yet to grease it like you're describing, Bob.

bob said...

What kind of head is that Mike?

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