Sodium Metasilicate

[Mardoo]

If I recall correctly Dr Smurto has given a PBW formula in another thread but ATM I can't find it.

 

[Black n Tan]

I would have thought Alpha Olefin Sulfonate would be closer to the surfactant used in PBW (Linear Alkylbenzene Sulfonates) than sodium lauryl sulphate.

 

[Black n Tan]

May be I am wrong...wolfy has proposed this formulation



Just an FYI, to make the equivalent of PBW, to the 70% Sodium Percarbonate 30% Sodium Metasilicate mix add:
Sodium laurilsulfate (detergent/surfacant, suggested mix 0.5-1%) is about $8/kg
EDTA (water softer, limescale remover, suggested mix 1-5%) is about $7/kg (only available in 25kg bags)

 

[MartinOC]

Any chemical-heads around that can clarify:

Doesn't Sodium Percarbonate break-down to Sodium Carbonate as it releases it's oxygen (the bleaching/sanitising agent) & Sodium Carbonate (the water-softener/surfactant) anyway once in solution?

I'm happy to stand corrected here, as I'm sure I'm using the wrong terminology.

 

[technobabble66]

FWIW, in that thread wally posted above, DrSmurto does confirm the 2:1 ratio of SodPerc:SodMet, but in post#13 of that thread he also mentions there are some other ingredients to prevent clumping, etc.
Those 2 are just the active ingredients.

Also FWIW, some people are a little wary of Sodium Lauryl Sulfate. It might have some side effects from long-term exposure.
This might be less relevant given it should be fairly well rinsed out(?) (dunno if it could cling to the plastics though ...)

 

[Black n Tan]

The two extra ingredients PBW use are a Linear Alkylbenzene Sulfonates (surfactant) and EDTA (water softener, to stop scale)

 

[orangehead911]

Thanks for all the replies.

I've been on a number of forums and what I've got seems to be about what people have suggested. The PBW formula uses SDS or sodium lauryl sulphate which is why it's in my formulation. It's used in cosmetics so I don't think long term exposure should be a problem, but in any case I always rinse with plenty of water and sanitize after.

Sodium Percarbonate does break down to Sodium carbonate. That's why I'm figuring Sodium carbonate is used as a filler.

I think I'll go ahead and make a small test batch tonight and see how I go!