24 inch telescope - sad news and how we overcome it

[Wah!]

多謝Zephix呢個咁正o既消息!!!

唔知鍍石英保護膜又有無打聽到呢?

[Chanlunlun]

我打聽到樟木頭有間廠可以做24"電鍍既工作 (鍍銀/鋁)均可~
但價錢未知, 如有需要可幫你問問價~~~

Dear Mr. Zephix,

Thanks for your assistance. Please obtain the quotation for me.

In addition may I make the reminder that the factory should carry out vacuum coating but not electroplating. They are two different process.

Best regards
Chan Yuk Lun

[Zephix]

Dear Mr. Zephix,

Thanks for your assistance. Please obtain the quotation for me.

In addition may I make the reminder that the factory should carry out vacuum coating but not electroplating. They are two different process.

Best regards
Chan Yuk Lun

佢地係做開呢類工作既, 我俾過少少你貼上黎既圖佢地睇
佢地就話知道點做同可以做到......

或者我問詳細少少再向大家報告~~

[simonii]

佢地係做開呢類工作既, 我俾過少少你貼上黎既圖佢地睇
佢地就話知道點做同可以做到......

或者我問詳細少少再向大家報告~~

靜候佳音
shipping 去樟木頭應該幾平
不過真係要睇下個質量

[Chanlunlun]

佢地係做開呢類工作既, 我俾過少少你貼上黎既圖佢地睇
佢地就話知道點做同可以做到......

或者我問詳細少少再向大家報告~~

靜候佳音
shipping 去樟木頭應該幾平
不過真係要睇下個質量

Dear Mr. Simonii,

I have to express our greatest gratitude towards your offering of assistance.

I'm waiting for your good news.

However if there is no news by next week we have no choice but proceed with, as what have planned for, the silvering job of the big mirror. As you know, the season of clean air and clear sky will soon arrive, the 24 inch has to see its first light as pers schedule. We cannot afford to miss the chance.

Thanks again for your effort.

Best regards
Chan Yuk Lun

[少爺]

如果每一個月,因為氧化(硫化?)要再鍍一次,經過一兩年時間的成本就變得很貴喇...所以我估要想辨法使到佢唔氧化才是真正達到低成本的效果.

長期令到層silver通住電,會唔會減慢氧化速度呀?

[sodium]

如果每一個月,因為氧化(硫化?)要再鍍一次,經過一兩年時間的成本就變得很貴喇...所以我估要想辨法使到佢唔氧化才是真正達到低成本的效果.

長期令到層silver通住電,會唔會減慢氧化速度呀?

咁咪仲貴?

[Wah!]

電費都蝕死?!有無效就真係唔清楚...

[simonii]

Dear Chanlunlun,
Surely, I wish I can help our honourable Mirror God.:-p
I have checked out the price for delivery by HK Post. The price is the same all over the mainland. For surface, 1st 1kg cost $100!!!!!Then $18 per kg in the following 6kg and $9 per kg up to 30kg.
But I know it will be much much cheaper for mail from the mainland to the mainload. Nearly $5 per kg up to 5kg and $1 per kg up to ...(haven't been mentioned)
Wishes,
simonii

[s360]

Dear Chanlunlun,
Surely, I wish I can help our honourable Mirror God.:-p
I have checked out the price for delivery by HK Post. The price is the same all over the mainland. For surface, 1st 1kg cost $100!!!!!Then $18 per kg in the following 6kg and $9 per kg up to 30kg.
But I know it will be much much cheaper for mail from the mainland to the mainload. Nearly $5 per kg up to 5kg and $1 per kg up to ...(haven't been mentioned)
Wishes,
simonii

但mainland既速遞服務水準令我擔心....(有可能會傷到塊鏡)....

[david_kmng]

Silver is such a good conductor that I wonder the amount of current that is necessary to keep it 'alive' will be so small.

[Chanlunlun]

如果每一個月,因為氧化(硫化?)要再鍍一次,經過一兩年時間的成本就變得很貴喇...所以我估要想辨法使到佢唔氧化才是真正達到低成本的效果.

Dear ATMs,

After a month's continuous exposing test it seems that we start to get an answer to the question of how long a silver coating can survive.

For the 10 inch pilot mirror resting in my home it does not encounter any further deterioration after the first two weeks' rapid change. The reflectivity is still very high although it gets a little bit hazy.

On the other hand it has been nearly two weeks after the silvering of the 24 inch mirror. At first the coating is perfect just like a fresh alumminized mirror coming out from vacuum chamber. After the first week with one field trip pf practical usage the coating deteriorated and the silver turned a little hazy. To make thing worse the mirror, according to some "tips" from internet, was wrapped by silk velvet ( for protection of silver, according to some "reliable" information ) which introduced additional grey spots onto the silver coating. ( so don't trust what you have seen on the Web that much ). However the silver seems to settle down to what it is now and no further change has been observed so far.

So it seems quite obvious that all silver coating should follow the same pattern of life - it gets a rather sharp declining in the first week and then settles down. The oxide formed on the silver surface prohibits further reaction, just like what aluminium does.

One thing - the 24 inch silvered mirror is presently stored inside our school which situates in Causeway Bay with the most terribly polluted air in Hong Kong. If the mirror can survive for one year it strongly indicates that silvered mirror is a good alternative to aluminized mirror in Hong Kong. At least for mirror of very big size it is much economic to coat it with silver rather than with aluminium.

All in all unlike what we are always hearing of and what it has always been taken for granted, silver coating is not that fragile and is quite stable in use. Given that the cost of silver nitrate can be kept modest ( by using industrial grade rather than analysis grade ) and the simple chemical procedure that anyone can follow, for those who wish to make mirror of giant size, silvering is a very good alternative to aluminization.

Best regards
Chan Yuk Lun

[Wah!]

有無試過洗銀水?會唔會使佢光潔如新?

[Chanlunlun]

有無試過洗銀水?會唔會使佢光潔如新?

Dear Mr. Wah!,

Thanks for your suggestion but at the moment I'm still not brave enough and the mirror is not worse enough to try this method.


Best regards

Chan Yuk Lun

[Wah!]

可以搵一塊細玻璃鍍銀來試試個效果喎!