Compass Light

Since I have the compass binacle opened up, I figured I might as well replace the old incandescent compass light with an LED. Ritchie makes a replacement kit, but it costs $16 dollars + shipping, which seems like a lot to pay for a couple of LEDs and a resistor.

So, I went to Radio Shack, and bought two LEDs for $2.00 (which is exorbitant), a a package of 560 Ohm resistors for 99 cents, and a small perf board for $2.00. First I cut the perf board to shape and drilled mounting holes which will use the same holes as the old light. I mounted the LEDs, and one resistor on the perf board. Then I wired the LEDs and the resistor in series. I tested it with 12v, and it works great. I put it next to the compass and turned out the lights. Ooooh, pretty. And it only draws 18 mA!

End of the bubble...

...well, almost. By now I figured that any air inside the compass would have worked it's way to the top. The bubble grew the first day, but since then it's been the same size. This evening I put the compass back on the bench, opened the filler hole, leveled the hole to get the bubble as close to the hole as possible, and injected a small amount of oil to top it off. I ever so carefully put the filler plug back in place, and returned the compass to it's upright position. There is still a really small bubble, about the size of a pencil point. I'd like to get it out, but it might be too much trouble.

Light Crude

The new compass oil arrived today, and I replaced it tonight. It was just as tedious as the first round, but I was rewarded with a working compass. The compass card stays perfectly aligned with North as I rotate the body of the compass. There is still a very tiny air bubble which I intend to try to remove tomorrow. Presumably, any additional air in the compass will work it's way to the top in 24 hours.

Bilge Pump

I went over to the boat on Saturday to install a new bilge pump. The winds were howling over there, and the boat was heeling in the slip. The new pump is a flexible vane type (Water Puppy), which worked perfectly once it was wired in and hooked up to the bilge hose. It's quiet too. Almost too quiet, as I won't be able to hear it running from on deck, which is how I used to keep track of any excess water coming aboard.

No ice in the river yet, it's been way too mild here for that. Maybe we can get through the winter without the de-icer.

The new compass oil should be arriving at my office today, according to the UPS tracking system.

Prospecting

I went looking for mineral oil last night. First I went to the hardware store, but they had just discontinued carrying it. Then I went to the local CVS. They had it, but it was about the same viscosity that I found in the grocery store. (BTW, I found out the medicinal purpose of mineral oil. It is used as a laxative. It's good to know that we will have a lifetime supply on board, stored conveniently in the compass).

So, I caved in and bought "official" compass oil from an online site. Cost: $30.00/gal. I don't need a full gallon (I need 66 oz.), but a half gallon wouldn't be quite enough. I'll have plenty to spare for refills down the road. At this point, my total repair cost is $100, including the cost of the oil that was too thick.

Compass Oil

The compass has a very small fill hole, so I decided to use a syringe to insert the oil. The compass holds 66 oz., so this turned out to be a tedious procedure. It took me about an hour last night to fill it up.

A friend told me that I could use any type of odorless mineral oil for this purpose, and not to bother buying expensive "compass" oil. I went to the grocery store and found some in the first aid section. "For intestinal use" it said on the bottle. (Someday I'll have to investigate what the medical condition is that requires such a use.) One thing that I noticed right away is that the new oil is more viscous than the oil that came out of the compass. I didn't think that would matter too much.

After filling, I noticed that the compass is almost unresponsive to rotation. It takes forever for the card to respond to a 90 degree turn. So long in fact that I got tired of watching it and came back this morning to see if it had found north. It had. Anyway, my conclusion is that viscosity matters a lot. I'll have to see if I can find some thinner oil at the drug store or hardware store. If not, I'll be buying some of that "special" compass oil from the compass manufacturer.

Compass Work

Over the weekend I removed to old dome and gasket and replaced it with the new one, carefully torquing down the screws in the retaining rings. It looks like I have a good seal now, so I should be able to replace the oil next. My only worry is whether I got the retaining rings back into the correct orientation for the attachment of the binacle cover. There are several holes where the screws will go, and it isn't obvious which holes are the important ones. I should have done a better job of marking the alignment. If I got this wrong, I'll have to disassemble the dome again, which means draining the oil and starting over.

Parts are in!

The parts for the compass have arrived. Now I have to get busy...