Q:

Using the word 为止 (with a time phrase)

我没知道存有椰子火锅到他吃为止。 
他吃椰子时(到)我没知道此存有为止。 
I am trying to formalize my grammar. 
Are either sentences acceptable. 
Would someone know what I am saying? 
I am not sure if I have to include the Time Phrase first or if I can leave the subject as 我 and then the independent clause would be 我没知道存有椰子火锅. 
May someone please tell me if these sentences make sense and how I would appropriately say this sentence?   Maybe give a few examples if there are certain variations one may use in this structure. 
I am trying to say "I didn't know there existed a coconut hot pot until he ate it/was eating it." 
The situation is I didn't know this existed and then I saw that one Instagram video with that caption about YE ZI . 
Could someone help correct my sentences and perhaps give me a new way of explaining this using WEI ZHI. 

A:

我沒知道存有椰子火鍋到他吃爲止。他吃椰子時(到)我沒知道此存有爲止。 

There are a couple of things that needs to be addressed about the sentence - unfortunately, in its current state, it is not legible. 

Chinese doesn't use the equivalent of English I never knew (我「沒」知道) - we usually say I didn't know (我「不」知道) or I've never heard of (我沒聽說過). 
「存有」is an exceedingly specialised philosophical term; to literally say exists in everyday language, the term is「存在」.  An example sentence might be

Ｘ（這種東西）不存在。 
There's no such thing as X.

The use of「爲止」here is problematic, and others have addressed how to use this term correctly. 

Using something natural like @xbh's example

在他吃之前我都不知道還有椰子火鍋
Before he ate coconut hot pot, I never knew it existed. 

is recommended, but as an exercise in using「爲止」, you can construct a grammatically correct statement like

我朋友剛剛吃了椰子火鍋。「到目前爲止」，我還不知道有這種東西。 
My friend just ate coconut hot pot.  Up until now, I didn't know there was such a thing.