Using ingot mould.... argh!

[RuthWinchester]

Hi everyone, I'm a complete newbie, so go gentle on me...

I'm trying to reuse scrap silver and have bought an ingot mold (reversible) and a whip & crucible, but every time I try to pour the molten silver into it, the silver solidifies instantly and forms a big lump on top of the mould. Very occasionally I manage to get a few mm of silver down into the mould but that's it so far.

I've watched a couple of youtube vids and they make it look really easy! What am I doing wrong?

(I'm warming the mould beforehand, moving the crucible close to the mould and keeping the metal molten until the moment of pouring - but still getting congealed lumps on top rather than nice clean sticks...).

I'm slightly wondering whether my 17mm Sievert burner is man enough for the job as it's quite hard work keeping the silver liquid? Or should I be really heating the mould so that it's not so much of a cold shock to the metal...?

TIA for any suggestions...

Ruth

[enigma]

Are you using flux before you pour?
And what nozzle do you have on the sievert?

[Dennis]

If you are only just able to melt the metal, then your torch is not really hot enough.
You talk about warming the mould, but it should be hot- nearly as hot as the molten metal.

Wile you are pondering what to do next, you might have more success with your present equipment if you pour into a groove in a heated charcoal block, which will not conduct the heat away so quickly. Dennis.

[RuthWinchester]

Are you using flux before you pour?
And what nozzle do you have on the sievert?

I've been fluxing the crucible and bits of metal fairly heavily before I start heating but haven't fluxed anything else - I didn't want to flux the ingot mould 'coz I expected a lot of hissing when I poured the metal! Should I be?

The burner might be part of the problem - it's a 17mm 3940...

Thanks!

[RuthWinchester]

Thanks Dennis - I will definitely give that a go. I've just ordered a 22mm nozzle as I think you might be right.

Would quite like to be able to use my (very expensive!) ingot mould too tho. So it needs to be properly scorching hot? Red hot?

While I'm here (and sorry to change the subject), my 17mm torch snuffs out the minute I get it at a slightly odd angle (which makes heating the metal quite an ordeal as I have to keep relighting it!). Its almost as though it's being blown out by it's own power. Anything I can do to prevent it? Its fine as long as I don't move it about too much! Gas cannister sloshing about so don't think it's running out...? And works fine in one position so probably not blocked...?

Thank you!

[enigma]

I was taught to add flux a minute or so before pouring although I use a kiln, I guess you would have to be careful with a torch as it will flare up?
And yes, agree with Dennis on the other aspects.
Tbh I don't personally rate Sieverts, you have to have the flame so huge it scares you to death to melt any amount of silver IME and they also seem to have a lot of issues with the nozzles playing up.
I have a Smiths little torch now and its such a joy to use after the Sievert.

[china]

As said above, torch is not hot enough, a Oxy/Lpg is a much better option, mold is not hot enough has to much more than just warming, are you lubricating the mold with oil, sounds like you may be holding the torch too close this will create a turbulent effect and extinguish the flame.

[Nick martin]

Hi Ruth.

To add to what the other folks have said, I'd agree with warming up the ingot mould prior to pouring.

Also another important step is to lightly lubricate the chosen chanel on your mould ( that you're pouring into ) with something like 3 in 1 oil. It'll help stop the molten metal from sticking, and you'll need a half decent powerful torch to heat the mould as its one big heat-sink.

I find that you can also create ingots quite easily using delft-clay moulds. Simply find an everyday object that fits the ingot shape you're after ( I use the shanks of my dapping punches ) then refine afterwards.

Also if you dont have a powerful enough torch, I can highly recommend the Smiths little torch. Or failing that, you could buy a £2-300 furnace / crucible setup that would allow you to melt with ease.

Cheers,

Nick