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Aster JNR 8550 & Aristocraft live steam Mikado
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Discussion Starter · #1 ·
Clumsy me. One of the fittings for the sight glass was tad loose, and it didn't take much pressure from an errant thumb to rotate the fitting and break the sight glass. I measured ~5.5mm or maybe 7/32" OD depending on the tolerances of these things. ~ 1mm wall thickness. the OD seems to be in between standard glass tube sizes. Found lots of 5 and 6mm OD glass tube. Has anybody replaced one of these on an Aristo Mikado?
 

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Aster JNR 8550 & Aristocraft live steam Mikado
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Discussion Starter · #2 ·
If I use a 5mm glass tube, is there an ideal method to seal up the extra half mm or so of gap around the two ends?
 

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is there an ideal method to seal up the extra half mm or so
Probably not. The top and bottom "gland" nuts that seal the tube in place are likely to have silicon sealing washers inside (I haven't had the pleasure of fixing one of these.) You may be able to fit thicker washers that will seal a smaller tube.

Take it (water glass) apart and post some photos so we can see how it is put together.
From the manual it seems conventional. The top nut allows you to remove or insert the sight glass through the top fitting and into the bottom one. Use a piece of brass while you align the top and bottom, then insert the glass tube.

62011
 

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This may or may not help, but I know nothing about this loco!
IF there is an 'O' ring on the outside of the glass that is compressed by the gland nut, you might get away with using the 5mm glass and a suitable 'fatter' 'O' ring.
Cheers,
David Leech, Delta, Canada
 

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A 5mm glass will be OK in the Aristo mikado fittings should you not be able to source a 7/32 OD glass. The o-rings will take up the difference without issue. Obviously the best solution is to replace like for like, but in a pinch, 5mm will suffice.
 

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Aster JNR 8550 & Aristocraft live steam Mikado
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Discussion Starter · #6 ·
A 5mm glass will be OK in the Aristo mikado fittings should you not be able to source a 7/32 OD glass. The o-rings will take up the difference without issue. Obviously the best solution is to replace like for like, but in a pinch, 5mm will suffice.
I would prefer 7/32" if I could find it.

I plan on measuring out everything for sure. I have this nagging feeling that I'm going to be tooling up and learning glass blowing stuff like fire lapping so that I can get back to my model train hobby.
 

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Aster JNR 8550 & Aristocraft live steam Mikado
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Discussion Starter · #8 ·
Sounds awesome. I sent you a pm.
 

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Aster JNR 8550 & Aristocraft live steam Mikado
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Discussion Starter · #10 ·
Sorry it’s been so long. Ryan’s sight glass worked well. Since there had always been a some tiny leaks from these fittings, I removed and resealed them all of them. The bottom fitting that connects to the back head was an M7x1.0mm straight thread sealed with some type of paper/cloth… like the type used in dollar Bills. I resealed it using Loctite 542 and ePTFE sealing washers from my master carr. I used a length of 7/32 k&s tubing in order to get all the fittings aligned while the loctite cured. The position of the fittings are secure now and no more leaks.
Thanks everyone
 
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