MkIII re-visited

A while ago I posted a thread on my T G & Co MkIII compass that I sent away to be refurbed and the twaats faffed the rotating index glass and lost a few screws, then handed it back broken and a note with sorry....we cannot fix this?
Anyway have been pondering the solution on the BA screws as a model shop that may carry them is 200+klms away anyway I digress.
I sorta worked out a way to do a reasonable clean of the bowl through the filling hole it is not 100% but at 98% I am not fussed it works.

You will need a syringe I used a TRUMO 12cc and one of those plastic tubes that connects to the spray nozzle of say an RP-7 can or WD-40 can.
Using a 2 mm drill bit by hand just open up the syringe nozzle end enough to accept the plastic tube from the can. (Pic 4)

If the compass has an air pocket in it that's good as it will help agitate the gunk I did not have to remove my bowl from the frame as the filler hole was on the top others may have to remove theirs remember what Peter said about the bellows underneath be careful of them.
1st Step ~ I removed the filler screw and gently agitated the fluid in there as it had an air bubble anyway do not be to rough with it, let it settle with the hole at 6 o'clock position (see pic 1)

Insert the tube into the hole and draw out the fluid re agitate and repeat until all is gone then using the syringe pre flushed with metho (clean it) refill the bowl with metho from the syringe with the hole at 12 o' clock (pic 2) do this slowly to allow the air to escape repeat 1st step until happy.

Now you can fill it with metho which is what I did as I did not feel like driving 27klms one way to get more Isoprophyl, metho is close enough to the refractive index as Peter has said.

With the filler hole at 12 o 'clock (pic 2) slowly fill the bowl until it flows out the hole and keeping the hole at 12 o 'clock put the screw back in but not all the way home just off nipped as we are going to use the sun.
What I did was prop the compass outside with it so positioned the filler hole was up top and the compass was tilted back so the air would gravitate towards the filler hole.
This is where physics comes into it I waited about 20 minutes until I could just see metho coming out the hole and without moving the compass tightened the filler screw.
As the liquid has a greater mass than air when it heats up it will push the air out of the loose filler screw this seemed to work.
Picture with compass flat on desk shows no bubbles and clear. (pic 3)
No bubbles and no gunk just have to wait for a new Index glass (on its way) and hand fit it so here is the guy Peter L put me on to pskettlewell UK e bay for MkIII parts.
And heres the guy in the Netherlands for the index glass on e bay westland*nl

So with that good luck and I know fleabay gets a hiding but it always has a item you may wish and a big thanks to Peter L for his assistance as there have been a few PM's between us.

Quote:

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Originally Posted by CINDERS

use the sun.

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Now it makes perfect sense. Couldn't imagine how we'd get an airtight fill otherwise.

Sometimes there are moments where simplicity just jumps out at you I hope the thread helps people because where I am so far from a reliable source of any expertise faffing things up can take months years to correct as who has the parts no one I know in this state has the parts for a MkIII and if they do they wont sell them........cheers

But there's a problem. The free-standing isoprophyl or methylated spirit has air in it in much the same way as water does. After a week or so you will see an air bubble forming. You've got to do the same again - and again - and again for several times before the iso inside the bowl is totally free of air.

Yours is a VERY early Mk3 with a top filler (later side fill) and screw-down lens (later clamp-down).

Just be advised that there are several versions of the rotating bezel too. One type has a bronze spring around the circumference while others click on and are retained by some sort of magic.

Quote:

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Originally Posted by Peter Laidler

do the same again - and again - and again for several times

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More good to know. So compasses didn't get returned for some time after re-build...not an overnighter like, say, a rifle.

Yep I will keep an eye on it Peter. Phil said the index glasses he got from this chap required minor adjustments and his were in degrees so here is hoping mine is as well I feel pretty chuffed to have figured a way to get it reasonably clean because as I have said I know on many occasions whilst this is a great land to live in getting parts sucks like a Kirby in a Sahara sand storm. Hope it is not Voodoo as I will have to get the Kadaycha man or the feather foot :yikes:

I for one really appreciate your input towards stuff Peter and whilst I may not be the roundest bowling ball I do listen to people I looked at what had to be done, what would happen if I broke the bowl glass and figured a way that was simple but safer for the compass not getting broken that would be the end of the project.
I do have a smaller one non filled that's next but I need to identify it must take some good clear pics it has no fluid in it so the card swings a bit freely will try tomorrow just has a couple of numbers on it no maker or anything I am hoping WWI issue anyway that's tomorrows effort.....