Borax Powder

[art925]

This morning I decided to clean out my metal cabinet, and found at the back an old bag of borax powder. Further investigation revealed this to actually be chrystals rather than a powder. I always thought that it would be possible to just make a paste by adding the borax to water, but it stayed as chrystals in hot or cold water. Is this product past its use by date, or should I try grinding the chrystals into a finer powder to make the paste? Before I use it to put a healthy shine in the bathroom, can I use it for soldering?

Thanks
Les

[Goldsmith]

Les, When I first started my apprenticeship as a goldsmith, back in 1961, my master would use borax crystals mixed with water as his flux for soldering. You will find that it bubbles slightly less than the flux made from a borax cone but works perfectly, providing that it is pure borax crystals. I have used a borax cone for my fluxing over the past 49 years and see no reason to change.
James.

[mizgeorge]

I use borax powder when melting to pour an ingot. It's very handy to just be able to sprinkle a bit over the metal, and also for conditioning the crucible before use.

[Dennis]

James (or anyone else for that matter), I've been meaning to ask you this: I apply my pallions with a brush, but if I want to add some once the work is hot, I use tweezers. The trouble is trying to let go, as they tend to stick to the tweezers. What do you do?

Sorry to but in art925, but it is a relevant topic. Kind regards, Dennis.

[mizgeorge]

I generally use a pick Dennis, but I suspect the answer might be titanium tweezers.

[jille]

I'm interested to read you can use borax as flux, I always have a saturated solution made up as i use if for my glass work. I wipe it over the glass surface to help prevent devitrification.
And it gets rid of ants

[Goldsmith]

James (or anyone else for that matter), I've been meaning to ask you this: I apply my pallions with a brush, but if I want to add some once the work is hot, I use tweezers. The trouble is trying to let go, as they tend to stick to the tweezers. What do you do?

Sorry to but in art925, but it is a relevant topic. Kind regards, Dennis.

Dennis, My soldering tweezers are stainless steel medical tweezers that I have filed to chisel point ends, I pick up a pallion of solder, dip it into my borax mixture in my plate, then I just blow the excess borax off the end of the tweezers and solder before attaching the pallion to the heated metal join area. Then the pallion just sticks to the hot metal and not the tweezers.
James

[Joe]

Brilliant stuff!

But poor old Les is still suffering with his insoluble borax! No, borax doesn't go off, it's a simple inorganic compound. There is a commonly sold borax mixture containing detergents and/or bleach which isn't suitable for soldering, but is also entirely soluble.

Perhaps that's not borax in the old borax box?

[jille]

I noticed that the brand f borax i buy has changed the contents, it's meant to be safer for household use so read the ingredients list on the box

[art925]

Brilliant stuff!

But poor old Les is still suffering with his insoluble borax!

I have had a play today and compared results of the borax powder water and my usual borax cone, with similar results. As Goldsmith suggested there appeared less bubbling, I guess this is due to my using saturated water with no actual borax. It worked great while casting, where normally I paint everything with borax paste from the cone.

Thanks everyone & Joe
Poor old Les,
(44, female):giggle:

[Dennis]

Thanks from me too, I guess it's more of the fff. Dennis.

[Joe]

(44, female):giggle:

To steal my namesake's line from Friends, "How you doin'?"

I guess it did dissolve eventually then!

[ps_bond]

There is a "borax" now being sold that isn't actually borax - the EU has banned the stuff as a household cleaner, so people are selling sodium sesquicarbonate as a "green" or "substitute" borax. I haven't yet looked in my local Chinese grocers to see if they've succumbed too.

It'll take a little while to dissolve crystals rather than powder, but it might go faster in hot water (or just pulverise them in a mortar). Anhydrous borax (as opposed to the decahydrate form we usually get our hands on) won't foam, which makes it lovely to use in forge welding - it melts and stays on the billet without bubbling up & wandering off elsewhere. Easy enough to make, you just heat it in the forge until it melts, then pour the resulting molten (glass-like) liquid onto a slab of stainless, then grind it once it's cool. A bit much for most uses though - and it'll happily turn back into the hydrated form as it absorbs moisture from the atmosphere.

[art925]

I guess it did dissolve eventually then!

No it still has not disolved Joe, it is from germany - 'Borax Pulver' on the label nothing else. I have been here in the Netherlands for 7 years so it could be so old. I must have bought it from one of my jewellery supliers because borax is not sold as a household cleaner here and my metal container is in my workshop.

...and thanks for the chemistry lesson too Peter.
Anyway it works.