How not to repair your compass

[smokn']

Funny story I thought I'd relate. I bought a dud of a Suunto Cobra console a few weeks ago. Not only did the depth sensor not work, but the SK-7 had a crack in it and was empty of fluid. Well, when I tried it in the pool, it partially filled with water. This gave me a brilliant idea: maybe I can just fill it with water and seal it back up! So I disassembled it and tried submersing it in water but it wasn't filling up, so I decided to make a small fill hole and then seal it back up (genius, right?). So, I got the smallest finish nail I could find (no hypodermic needles nearby), heated it up with a torch, and stuck it in the base of the compass. It cut through like butter, all was going smoothly. I proceeded to fill it with water. That went well too. Then, I heated the nail up again so I could smear the plastic back over the hole. Well, the plastic shrank away from the heat to the point that there was only a very thin layer of plastic. At this point, I realized that the entire top of the compass was filled with cracks (I had to fill it with water to discover this) so I flipped it over and water poured out of my newly made patch. Comedically infuriated, I tossed it in the trash and walked away. Just thought I'd share my brilliant idea last Friday.

 

[Gombessa]

I never really considered this before, but do you even need to seal the hole back up? Depending on what the pin and compass card are made of , can't you just make a big enough hole so it fills with water when you submerge?

I guess another possibility is to fill it up and aquaseal a flat piece of clear tubing over the hole, it shouldn't need to be rigid.

 

[The Chairman]

I never really considered this before, but do you even need to seal the hole back up? Depending on what the pin and compass card are made of , can't you just make a big enough hole so it fills with water when you submerge?

I guess another possibility is to fill it up and aquaseal a flat piece of clear tubing over the hole, it shouldn't need to be rigid.

Sure, why not? The fluid (light oil) is only there to dampen the needle movement and to defeat Boyles' Law.

 

[TSandM]

Thank you for a how-not-to! I've had a couple of Sk-7s lose their oil, and I've thought about refilling them, but I hadn't really thought about how to make the hole to do so. Now I'll know not to do it with a hot nail!

 

[captain]

If the internal parts are made of non corrosive material letting it fill with water would work except for one big problem. Non corrosive materials can not be magnetized so the needle is some form of steel or iron that will rust way rapidly.

 

[Gombessa]

If the internal parts are made of non corrosive material letting it fill with water would work except for one big problem. Non corrosive materials can not be magnetized so the needle is some form of steel or iron that will rust way rapidly.

I haven't had the opportunity to look under the compass card for the needle, but I was thinking there was an off-chance (very off) that it could somehow be sealed inside the compass card. Wouldn't make a whole lotta sense to go through the trouble though.

 

[dgreenh]

Funny, I had almost the exact same experience with my SK7. I realized the top was cracked before I tried to reseal the hole though. It is resting peacefully in a landfill somewhere now.

 

[smokn']

Gombessa, I considered this but got tired of it slowly leaking out on everything. Captain, good point. dgreenh, glad to know someone else has been through part of my plight!

 

[The Chairman]

the needle is some form of steel or iron that will rust way rapidly.

Rapidly? Not sure about that! It's only getting submerged an hour or two at a time and then staying fairly dry. If the magnet is encased in plastic, then even this is moot. It's not going to cost you anything to try!

 

[knotical]

the needle is some form of steel or iron that will rust way rapidly.

Don’t know what type of magnet is used in underwater compasses, but since many magnets are ceramic, incorporating one of the iron oxides, would they rust more?