Topping up fluid in a Plastimo 135 compass

[KASHMIR]

I have a 20 year old Plastimo compass on my boat and over the last few years and bubble has slowly appeared in the top. Can this be easily topped up? Does the rubber diaphram need to be changed? What sort of fluid is inside these things and assuming it is possible to do, are there any tricks?
TIA

[model 10]

Originally Posted by KASHMIR

I have a 20 year old Plastimo compass on my boat and over the last few years and bubble has slowly appeared in the top. Can this be easily topped up? Does the rubber diaphram need to be changed? What sort of fluid is inside these things and assuming it is possible to do, are there any tricks?
TIA

By all means change the diaphragm and use compass fluid, not something like whisky. Aircraft Spruce and Specialty has pint cans of fluid. It smells like solvent but it's not. Almost anything else you might use will either yellow everything inside or destroy the diaphragm.

[KASHMIR]

I tried phoning all over East coast Australia this morning to get hold of some of the fancy fluid but was not successful, so back to the web and I found on another forum someone recommend baby oil, so I got some babies and extracted the oil... just kidding, I put some baby oil in a small container and tipped in a sample of the existing stuff in the compass and it mixed fine, so I filled the compass full, put the unit in the freezer, apparently it makes the air go out of the oil and now my compass is all good again and I can re-fit it back to the back and most likely never look at it again.
Thanks for your help Guy.

[Benny35]

I’m having trouble locating the oil fill on my Olympic 135 compass. Any tips?

[billknny]

Originally Posted by Benny35

I’m having trouble locating the oil fill on my Olympic 135 compass. Any tips?

The local compass repair shop told me that Plastimo Olympic 135 compasses are fully encapsulated, and are not repairable.

I guess this is a "good news/bad news" thing. Good news, the diaphram doesn't need replacing every few years as a routine matter like some, on the other hand when it does fail, you are in the hole US$275 for a new one. Mine lasted 23 years, which seems typical.

[NYSail]

I sent my old compass, a Ritchie back to the company and had it rebuilt. Came back beautiful and much cheaper than new. Call the company and see if they have this service.

Good luck!
Greg

[alamoana]

I worked on an old Plastimo 135. Put the compass and fluid in the freezer the day before filling it. Fill it, let it sit in the freezer a day and refill. The bubble did not show up again.
Good luck

[SilentOption]

As billknny said the Plastimo 135 is not repairable. I called every place I could think of and nobody would touch them.

[Jeanneau 45.2]

I have 2 of these on my boat. Guess the lesson to be taken is to always close the sun cover when not using.

[sparrowhawk1]

Many years ago I had a completely sealed compass in my cockpit bulkhead with a bubble that was getting so big I couldn't read it so I drilled a tiny hole in the top, used a hypodermic needle to inject mineral oil and then put in a plug. In direct sun some of the oil came out and then when it was colder I would have an air bubble but that was okay because I could still read the compass with no problem.

[Allied39]

I re furbished a ritchie globemaster years back that had a leaky diagram. As instructed by ritchie I put the oil under vacuum , overnight if I remember correctly.
I released the vac, poured the oil in, as full as possible and installed the plug. Right way up a couple of bubbles appeared, as expected.
I can not remember how long it took, but the bubbles soon disappeared,
All good , happy ending.
Something to keep in mind.

[Benny35]

Thank you.

[sparrowhawk1]

I forgot to mention that baby oil is just mineral oil with perfume

[HermanTheGerman]

I just successfully repaired a Plastimo compass that probably original to my boat, i.e. from 1985.

It was sealed, but the advice below that I found on the web helped me. The crucial point was that the fluid actually seems to be propylene glycol. I got some food grade quality from Amazon and it blended with the existing fluid with no problem.

A few additional tips:

Make sure the fill hole is always at the very top of the compass. So a coffee mug as a stand probably won't work, but a cookie jar with a 5 inch opening did. Check often, even a millimetre in height can make a difference.

Fill in the fluid in very careful small increments. When it's almost full, slow down and pump some fluid in, let it set (i.e. air escape), and then do another tiny pump.

I didn't put the compass or fluid in a freezer. Propylene glycol is used as antifreeze, so I figured it wouldn't shrink when cold, but maybe this is not true.


When you're done, put silicon back over the filling screw. Next time you do this, you need an absolutely clean fill hole, so the silicone keeps gunk from getting in.

I had all but a pinhead size bubble left when I had used up my 8oz bottle of fluid and was a little annoyed by that, but the next day that tiny bubble was gone. Maybe the fluid absorbs some air.



And here is the post I found on another website, which had no formatting but was right on the money:

I just repaired two (2) Plastimo 95 Offshore Compasses that had substantial bubbles in them - despite the housing having stamped on it NON-REFILLABLE - not true.... VERY much refillable! I chose to NOT use Glycerin as it has a higher density and viscosity and will create streaking and bubbles in the compass (albeit in the bottom of the compass... but still visually not perfect). What PLASTIMO will NOT tell you is that they use simple PROPYLENE GLYCOL... harmless and easy to procure, especially these days as it is a component in custom-made vaping-solutions for e-cigarettes!

Here is what you need:
- Propylene Glycol (got mine on eBay); hereafter shortened to "PG"
- Simple stubby-nosed syringe (got mine at Walmart)
- Silicone, Clear (like the kind for your indoor shower caulking job)
- Screwdriver (flat or phillips depends on the screw on the underside of the compass)
- Coffee Mug (empty)

here is how I did it (successfully twice and now installed and one indoor in the shade and the other outdoor baking (under a cover) in the sun and BOTH are doing great:
- Uninstall compass from boat
-Flip the compass upside down into a large coffe-mug with the filler-port in the highest spot
- Use the narrow blade of a flat screwdriver (I do NOT recommend an EXACTO knife - too sharp) to carve out the silicone installed at the factory inside the recess above the filler-port screw (there exposing the screw-top for the screwdriver)
- Clean out all remnants of the silicone'
- Unscrew the screw and NOTE there will be a face horsing that will come out with it - set aside and make sure threads and screw head and o-ring are free of any debris
- Suck up PG into syringe, turn upside down and expel air
- slowly inject PG into compass through filler port until PG covers to the top of the filler-port threads (OK if a bit above, but NOT OK if below to avoid entrapping any air)
- reinsert and thread down filler-port screw with o-ring underneath haed
- do NOT over tighten as it is a brass/bronze screw in a plastic threaded body!
- wick out all PG above the screw head with a paper towel and wipe it clean and let it dry (yes, it does evaporate, albeit slowly. You can speed it up with an alcohol wipe using Q-tip)
- Add a dab of silicone to fill recessed filler-port cavity above screw and let set with filler-port facing upward with compass still sitting atop the mug.
- You are done!

[Seafarer48]

I was able to refill my Plastimo 135 Compass to eliminate the bubble. Most of the posts are helpful, but I removed some plastic from around the fill port and slipped a 6" piece of 3/8" ID plastic tubing over the port, after removing the filling plug. I slowly added Ritchie Compass Fluid until it was 4" up on the tube, with the compass tilted such that the fill port was at the high point. Next, I massaged the rubber diaphragm, which dislodged the trapped air, several times. Finally, I dropped the filling plug down the tube and tightened it in place with a long thin flat blade screwdriver. This method put some pressure on the compass fluid.
When I turned the thing right side up, there was only a tiny bubble left. I repeated the process, and eliminated the bubble.
Lets see how it holds up!