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Venetia2004
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Reged: 08/27/05
Posts: 184
Loc: Lynnwood, WA
Barnesite vs Rouge for figuring
      #2691458 - 10/10/08 04:30 PM

Hi All,

Is Barnesite better than Rouge for figuring? I know that Barnesite polishes faster than Rouge. Does it deliver a smoother polished surface?

Thank you.

Vic


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JohnH
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Reged: 10/04/05
Posts: 492
Loc: vancouver near the wilds of B...
Re: Barnesite vs Rouge for figuring new [Re: Venetia2004]
      #2691592 - 10/10/08 05:46 PM

From what I've heard about these materials is:

Rouge and Barnesite both stain clothes badly. I managed to polish three mirrors using rouge, and only got it on my hands.

The old timers who used Barnesite is slightly slower and easier to control and is about as smooth as Rouge. Tom, an old member of BEAS, said it made a big difference when he was deepening two mirrors into hyperbolic sections for an RC.

Most say they gey a higher quality of polish using the two above rather than cerium oxide.

I am getting some Barnesite from his clearing out old stuff, so I'll let you know who it goes.

Edited by JohnH (10/10/08 05:47 PM)


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Venetia2004
super member


Reged: 08/27/05
Posts: 184
Loc: Lynnwood, WA
Re: Barnesite vs Rouge for figuring new [Re: JohnH]
      #2691642 - 10/10/08 06:11 PM

Thanks John. I've used Rouge, and the mirror came out very smooth.Besides a correct figure I want my mirror to be also very smooth.I've never used Barnesite.

Regards,

Vic


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DAVIDG
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Reged: 12/02/04
Posts: 1429
Loc: Hockessin, De
Re: Barnesite vs Rouge for figuring new [Re: Venetia2004]
      #2692155 - 10/11/08 12:15 AM

I've used Rouge, Barnesite and Cerium oxided. I find no difference in the quality of polish or the smoothness of the figure if proper polishing techniques are used. Modern day cerium is very even in it's particle size. What I have found makes a difference is making the polishing solution acidic.
Barnesite is cerium with a couple other rare earth oxides. Some say it is slightly radio active. I don't believe that any one makes it any longer. The Barnesite I have came from the 1940's. Rouge, since it is iron oxide forms clumps and will sleek if not milled and kept in water. If you mill it and don't place it in water in a short amount of time it will clump up again. Rouge will stain, I haven't found Barnesite to stain.

- Dave

--------------------
Homemade 'scopes 8"f/7,6" f/5", 6"f/4, 4.25" Schief. 60mm Coronagraph,60mm H-alpha system, 4.25" White-light Solar Newtonian,solar spectroscope, 4.5" f/16 Schupmann Medial refractor, 14 Stellafane awards 7 in optics

Engineering = Taking what you have and making what you need.


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Venetia2004
super member


Reged: 08/27/05
Posts: 184
Loc: Lynnwood, WA
Re: Barnesite vs Rouge for figuring new [Re: DAVIDG]
      #2692184 - 10/11/08 12:31 AM

A while ago I bought an old mirror kit that came with all the grit, pitch and a little jar with Barnesite. I just wanted to try figuring with Barnesite.
Thank you for the information Dave.

Regards,

Vic


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