Compass: repair, replace, check

Repairing a forty-year-old compass

On my first night outing this season, I noticed the compass behaving strangely. No illumination, and the card spun wildly at the slightest movement. Without visual references, I wanted something to help hold a course.

Closer inspection revealed the problem: all the liquid had leaked out. Removing it exposed numerous cracks in the back. I tried welding them together with a soldering iron, then coated the surface in Sikaflex for good measure.

What to fill it with? After advice and internet searches, I bought purified paraffin oil for €15. Nearly an hour with a 5ml syringe transferred half a litre of viscous liquid into the patient. Delighted — until oil began running down my hands through the sealant.

The sealant also blocked access to the plastic. I took the compass home and spent four evenings scraping off all the Sikaflex with a flat screwdriver. However much I welded, new gaps appeared. So I bought €15 two-part epoxy at Bauhaus and covered the entire back. Amazing: completely watertight.

Back at the yacht, the oil had turned white. Heat from the soldering iron, or traces of Fairy and alcohol used for degreasing? I don’t know. Another hour draining and refilling.

I fitted the compass in its rightful place and admired it, only to discover that the card had fallen off its pivot and now lay at the bottom, with no way to put it back.

#maintenance

New old compasses

Giving up on the old compass, I looked for a replacement, ideally without enlarging or reducing the hole in the hull. The original Silva 100P was my first choice.

On eBay and Kleinanzeigen, the local classifieds sites, I found an original Silva 100PT from the eighties, never used, for €25! New ones cost about €180. A sign from fate. Its only fault: a little oxidised metal sediment inside the bowl.

I bought €4 worth of 3mm red LEDs on Amazon, with built-in transistors for a 12V circuit. Fifteen minutes to fit and test.

My appetite for bargains persisted. Two more parcels arrived: a French Vion Mini 2000 hand-bearing compass and a Swedish Silva Type 60. €25 each.

The Vion resembled today’s popular Plastimo Iris 50. Unfortunately, half the liquid had evaporated and the tritium no longer glowed. Its little disc was removable, though, so I took it out and covered it with self-adhesive luminous tape.

The liquid was quite thin. After asking ChatGPT, I guessed purified paraffin or 70% alcohol. A sealed rubber disc sat in the side. I inserted a syringe needle and pumped air in until the bottom popped out. The room filled with a diesel smell. Washed everything with Fairy and reassembled. Filled the syringe with 70% ethanol, injected through the disc, drew out excess air, and repeated until it looked usable. Like new now. I sealed the disc with my wife’s nail varnish.

I liked the Silva Type 60 even more: two scales show both bearing and reciprocal. Its drawback was an exhausted tritium capsule I couldn’t work out how to remove. No good for night passages, then.

#maintenance