Servicing the Calypso Depth Gauge...
- It's tough to get a Calypso depth gauge in good shape. I've been messing with one after another for a couple of years and I think I've learned how to restore/service them. I have three and have cobbled together two out of the three that are working well. The one with the best lens had the internals of the bourdon tube completely clogged with corrosion. My best one was a newer version with orange face and black plastic case... Identical to the chrome ones except for a larger pressure port screw. This one was brand new in the original box... Had never been wet. It leaked completely the first time I dove it. So, I would recommend servicing even to ones that appear in the best condition. Here are a few tips:
1. These are supposed to be just air inside... Don't fill them with oil.
2. Don't try to pry the lens off. It is held in by suction and will chip and then crack across the face. The lens is VERY fragile.
3. Make/grind a proper spanner head screw driver so you can unscrew/screw the pressure port without damaging it.
4. There is a weird O-Ring arrangement that needs to be replaced for reliable seal. It's weird because it seals the gauge to the case to the pressure port... three surfaces. I don't remember the O-ring but I found exact replacements at my local Ace Hardware.
5. If the lens is fine, I recommend not trying to take it off. If you want to swap in a better (not cracked) lens from another Calypso, then the best way to remove the lens is by inserting a jewelers screw driver into the pressure port (with the screw out) and pushing the whole internal mechanism up against the inside of the lens. It will pop out and reveal a very thin O-Ring seal around its circumference.
6. Re-Assembly Procedure: Install the lens first. If you don't you will not be able to fully insert it against the air pressure inside when the pressure port is sealed. So, Lens first. Then pressure port with new O-ring. I recommend silicon grease on the O-ring so that it will settle into the three surfaces it has to seal.
7. The quality of the spanner screw driver you made is important. The pressure port not only seals everything against the O-ring, it also secures the mechanism in the case. So you need to get a good purchase on that pressure port and screw it all the way in tight.
Saving a Flooded Calypso - Drying out the inside is nearly impossible without removing the lens. But I don't recommend removing the lens unless absolutely necessary. I was able to dry out the insides of my flooded gauge without removing the lens, here's how:
1. Unscrew and remove the pressure port.
2. Empty out the loose water.
3. Fill the case about 1/4 full of rum. Shake it around to mix with any water residue. Empty out the rum and repeat.
4. Now, to evaporate the rum residue, place the gauge on your dashboard in the sun with the pressure port facing up so that the rum vapors can escape. Just let it sit in the sun like that and the heat will dry it out completely.