View Single Post
Old 28th Feb 2007, 9:47 pm   #7
Framer Dave
Rest in Peace
 
Join Date: Dec 2006
Location: Near Wrecsam, North Wales
Posts: 356
Default Re: Screen magnifiers - 40s/50s TVs

We are close to the bottom of this now. I drew off about 50ml of the fluid, which could be seen to have a distinct yellow tint. I soaked a piece of paper in it and lit it. It burned with a yellow smokey flame. Bad move! - right under the workshop smoke detector (linked to the others in the house), causing great agigtation in the other resident. The fluid is not miscible with water and is tasteless (I did this 2 hours ago, so probably not poisonous either). Conclusion: may very well be liquid paraffin.

The flat back part of the lens extends into a flange around the unit. This part of the Perspex is perfectly clear, so I assume the rest is likewise.

Tomorrow I will add a small amount of Liquid Paraffin BP to one of the magnifiers and see if it mixes. If so, I'm going to drain it and refill completely. I don't know how much I'll need - hope this stuff is not too expensive!

Empirically,

Dave

Update: I've now drained some more of the fluid and can see that the main part of the lens is also clear.
Framer Dave is offline