Borax and Lye Instead of Metaborate, any issues?

[athbr]

Sodium metaborate is for some reason ludicrously expensive in my country. Borax and Lye are ludicrously cheap.

I've run into Anchell's substitution: 9.5g lye + 45.4g Borax + water = 1L @ 10%

I have no background in chemistry to debate this. Just wanted to know if there is any practical difference to this and sourcing proper sodium metaborate in powder form.

For reference this is to formulate Mytol. Will my results suffer if I do this? Should I just by the metaborate?

Thanks.

 

[athbr]

PS: I've seen this thread before which is helpful.

https://www.photrio.com/forum/threads/sodium-metaborate-from-borax-and-lye.29779/

Good advice on how to make the stuff. What I wanted to know is if it is indeed the same if you do it yourself.

 

[koraks]

FYI, this is the formula I use for instant mytol. It works like a charm:

Hot water 500-750ml
Borax 1.4g
Sodium sulfite 60g
Ascorbic acid 11.5g
Sodium carbonate decahydrate 13g
Phenidone 0.15g
Add water to make 1000ml

Adjust pH to 8.20 with 10% NaOH or vinegar (acetic acid).

The sodium carbonate decahydrate can be replaced by monohydrate or anhydrous by applying the appropriate conversion factor. I use decahydrate because that's the cleaning soda I buy at the supermarket.
The ascorbic acid can be replaced with ascorbate; the carbonate must be reduced by a little to compensate for this.

 

[athbr]

Hi Koraks,

I am trying to understand the math here. Sorry, just learning about molar weights.

How exactly does the Sodium Ascorbate and metaborate get created here?

I'm assuming Borax + Sodium carbonate = Sodium Metaborate.

Is the Borax doing double duty with the Vitamin C to get Sodium Ascorbate?

Also, in theory, should a solution like this work just as well? Will there be any improvement to developing by using straight metaborate and Na Ascorbate?

cheers

 

[koraks]

Well, there's probably a small difference depending on the order in which the ingredients are mixed; if the carbonate is added before the ascorbic acid (so the reverse from how I listed it above and how I actually do it), the metaborate will be formed first by the carbonate + borax, and consequently the ascorbate is formed as the ascorbic acid is formed. I'm not sure if the difference is significant, but it should be negligible if the pH is adjusted afterwards to 8.20.

Theoretically there should be no difference whatsoever between this approach and starting with metaborate and/or ascorbate. With the formula above you end up with metaborate and ascorbate in solution anyway.