US source for Carr's Red Flux (white metal soldering)

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1

I seem to have lost my precious bottle of Carr’s Red Flux used for white metal soldering.

It is only available in the UK and won’t ship to the US. My understanding that it is 6% phosphoric acid but I can’t seem to find a source for that in the US either. Much more concentrated phosphoric acid is available but in giant quantities and I’m not nuts about buying that and diluting it.

So, what do US-domiciled modelers do when they want to solder white metal kits (in my case, Langley Models kits) and they need the right flux?

2

A US product which may or may not be an equivalent is Wilders’ SF01 soldering Flux, I believe intended for PE soldering.

Caution! my bottle top was fragile, broke & it ate my cutting mat!