Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Model & Toy Steam Engines – Stirling Cycle – Flame Lickers – Small Antique Originals => Topic started by: Jim on November 16, 2020, 04:23:01 pm

Title: Re: Jensen Sight Glass
Post by: RedRyder on November 17, 2020, 08:41:53 am
That is a great and simple upgrade, Jim.


Very well done...!


It boggles the mind that Mamod would use a plastic site glass.



Title: Re: Jensen Sight Glass
Post by: St Paul Steam on November 17, 2020, 06:25:05 am
looks like you made a sound repair Jim, well done.
Title: Re: Jensen Sight Glass
Post by: Jim on November 16, 2020, 09:38:28 pm
As thick as that is and the way it’s secured, I don’t think it’s going to give you any troubles...

Its bedded down on the Mamod silicone water seal. There's only the size of that keyhole opening that you can see in the brass retainer through to the boiler.

Ran it for two hours now with a few top ups with the safety valve blowing off. I think that's a pretty good pressure test.
Title: Re: Jensen Sight Glass
Post by: Nick on November 16, 2020, 09:34:25 pm
As thick as that is and the way it’s secured, I don’t think it’s going to give you any troubles...
Title: Re: Jensen Sight Glass
Post by: Jim on November 16, 2020, 07:04:43 pm
Had the safety blowing off for 5 minutes and all good (so far) and no leaks. Nice to be able to see the water in the boiler.

https://vimeo.com/480102094
Title: Re: Jensen Sight Glass
Post by: Jim on November 16, 2020, 07:03:14 pm
Just cut the glass, it was easier than I thought. Edges came out nicely ground. The Mamod perspex is in the middle.

Now to give it a test drive.

[attachimg=1]

[attachimg=2]
Title: Re: Jensen Sight Glass
Post by: Jim on November 16, 2020, 06:27:33 pm
Bruce, took the Mamod Centurion sight glass off before to clean behind it as its getting hard to see the water level. Discovered its only made out of plastic/perspex.....that's a bit cheap on Mamod's part?

Its totally discoloured and there's no way of making it clear again.

The thought crossed my mind of cutting a piece of glass that I have which is the same thickness, the sight glass is held in with a brass holder and two screws, there's only a 'keyhole' of glass visible.
Title: Re: Jensen Sight Glass
Post by: St Paul Steam on November 16, 2020, 05:49:40 pm
Tube or  porthole would be my question ?  either way I don't think so dealing with the low pressures we require of the boilers  , as long as the thickness is adequate,  I have bought many feet of the tube style  over the years.  The stock porthole glass leaves a little to be desired in many instances.
Title: Jensen Sight Glass
Post by: Jim on November 16, 2020, 04:23:01 pm
Does anyone know if there's anything special about the glass Jensen uses for their sight glass?