Help me.(Stripping the Aluminum Coating from a Mirror)

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Help me.(Stripping the Aluminum Coating from a Mirror)

Post by mami813 »

Hi, everyone
I have a 12-inch mirror from Orion Optics in the UK.
I decided to remove the aluminum coating for use in solar viewing.
However, although sodium hydroxide was used, the aluminum coating did not disappear.
Does ferric chloride disappear if used?
If it doesn't disappear in this way, is there no way?
Thank you.
Jong Ho.


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by steveward53 »

Hi there ,

A quick in-house 'search' threw up plenty of mentions of the topic here on Solarchat ... ;)

search.php?keywords=mirror+stripping

And there are a couple of good YT videos explaining the procedure ... https://www.youtube.com/results?search_ ... ope+Mirror

My only advice regarding the first video would be to put the mirror in a suitable container before adding the solution , relying on a strip of packing tape to retain the solution while you try and lift the 'full' mirror and maneouvre it to empty the fluid is a messy disaster waiting to happen , the chap in the video has done this umpteen times before ... ;)

This is something I considered a while ago so I'm eager to know how you get on , please keep us posted as to progress .

Regards ,

Steve.


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by allhoest »

Hi Jong Ho,

I have stripped several mirrors. Here a summary of one easy case and of one difficult case:
viewtopic.php?t=37485
viewtopic.php?t=26525

I'm using Iron chloride, the same product for electronic printed circuit boards.
Does it arm the mirror? Some people says so; I don't think so. Here pictures made with the 300mm after stripping.
Just to be sure, take the mirror out of the Iron chloride and flush it with distilled water as soon as possible.

CS
Alex


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by marktownley »

I'd say that worked Alex ;)


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by thesmiths »

I also used Ferric Chloride. I worked really nicely viewtopic.php?t=11814, as it did for Bart viewtopic.php?t=25766

The trick with masking tape around the edges worked well for me. Don't forget the bicarbonate of soda to neutralize the ferric chloride afterwards. Then the liquid is pretty harmless. I needed to do it twice to get all the aluminum off. It probably depends how thick the metal is and if there is a coating on top or below the aluminum.


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by mami813 »

allhoest wrote: Sun Aug 21, 2022 8:02 pm Hi Jong Ho,

I have stripped several mirrors. Here a summary of one easy case and of one difficult case:
viewtopic.php?t=37485
viewtopic.php?t=26525

I'm using Iron chloride, the same product for electronic printed circuit boards.
Does it arm the mirror? Some people says so; I don't think so. Here pictures made with the 300mm after stripping.
Just to be sure, take the mirror out of the Iron chloride and flush it with distilled water as soon as possible.

CS
Alex


Image

Image
It helped me a lot.
Thank you, Alex


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Re: Help me.(Stripping the Aluminum Coating from a Mirror)

Post by mami813 »

thesmiths wrote: Sun Aug 21, 2022 8:26 pm I also used Ferric Chloride. I worked really nicely viewtopic.php?t=11814, as it did for Bart viewtopic.php?t=25766

The trick with masking tape around the edges worked well for me. Don't forget the bicarbonate of soda to neutralize the ferric chloride afterwards. Then the liquid is pretty harmless. I needed to do it twice to get all the aluminum off. It probably depends how thick the metal is and if there is a coating on top or below the aluminum.
Thank you for the information that needs to be neutralized with bicarbonate.
Thank you.


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