Marklin sight glass help.

Marklin sight glass help.
Posted by Earlytimes on 24 Apr, 2021 18:36
I'm cleaning up a Marklin 4112/ 10 with tile base to run and was resealing the sight glass. I have 7mm glass tube but this is smaller and tin walled tube. I think it's the original. My 7mm tube is too big and 6mm is too small. The fittings are the original Marklin square blocks with the weird little inserts. I of course I broke the old glass.
Has anybody run across this glass size ? I've done Marklin sight glasses before but haven't run into this glass size. Thanks for any help.

#1 Reply
Posted by Earlytimes on 25 Apr, 2021 17:46
I think I have this sorted or on the way. The right size glass is the key. I have replaced these sight glasses a few times but this engine is older and the sight glass is just a little smaller in diameter @ 6.35 mm and thin walled so none of my glass stock would work. I'll post my fix when it happens.

#3 Reply
Posted by Earlytimes on 29 Apr, 2021 20:10
Well I got some glass tube today from North Carolina and while it was better it wasn't a perfect fit. Ideally you want to be able to drop the sight glass down from the top passing through the block fitting that holds it, but it was just a little too big in diameter. I had to slip it in while tightening the fittings. The sight glass goes in bottom fitting before it's completely tight then turn the fittings together to get it to slip into the top. If that makes sense ?
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I tried to post a photo but didn't have any luck..... I'll figure it out later.

#4 Reply
Posted by txlabman on 30 Apr, 2021 12:36
Make sense to me. Were you able to put a gasket on each end on the outside of the sight glass inside the fitting?

#6 Reply
Posted by Earlytimes on 30 Apr, 2021 16:19
Heres another video of the little Marklin and me talking to myself.

https://youtu.be/J0U9xcyrOnA

#7 Reply
Posted by RedRyder on 30 Apr, 2021 17:38
I found that 7 mm, while slightly larger than the original, could be fit after doing a real good clean out of residue on the site glass parts.
Bob, my Marklins may have been a little newer than yours.

#8 Reply
Posted by Earlytimes on 30 Apr, 2021 18:36
Quote from: RedRyder on 30 Apr, 2021 17:38
I found that 7 mm, while slightly larger than the original, could be fit after doing a real good clean out of residue on the site glass parts.
Bob, my Marklins may have been a little newer than yours.

Hi Gil, I never had this problem before that I recall ? When I ordered glass I bought two different brands thinking one might be a little smaller. I ordered 1mm standard wall thickness which helped as my older glass tube must have had a thicker wall, 1.5mm ?

#10 Reply
Posted by Earlytimes on 30 Apr, 2021 18:58
"Oh my. What a beautiful engine.

Thanks for posting the video and it is great to see no leaks in the sight glass."

Thanks Charlie, I made the last glass by just going slow and fitting it as I went.