Rescuing overheated silver for casting

As a new hobbyist, I’m trying delft casting. I was successful with my first piece but last time I used too much silver (grains) for my butane torch (in cold weather), so it didn’t get hot enough and it didn’t pour properly. As I was heating for at least 15 mins, the silver now has a ‘lovely’ green and red hue and looks porous. Can I just remelt it? Should I pickle first? Or is it ruined?
Thanks for any advice. I’ve only just found this forum so I found what I’d done wrong but don’t have the knowledge to correct it.

Re-melt it with plenty of borax, then pickle, and you will have a button of clean silver. Welcome to the forum Dennis.

Many thanks Dennis. I’ll have another go, hopefully the warmer weather might help the torch!

A warmer room will help a little, but really it's better to get a bigger torch, even if it is only a DIY plumbing one. Dennis.

If doing a lot of Delft Clay casting a large torch will really help. It’s so easy to pour prematurely before the metal and crucible are properly hot producing disappointing results … N

Hi, Following your advice on a better torch for my casting, I’ve been bought a sievert torch to go on a propane cylinder. I now find that I can’t buy new cylinders near me from flogas or calor. They are only doing refills or green leisure cylinders (which I understand are low pressure and no use). Does anyone know of any other types of propane cylinder I can use, maybe with an adapter to fit the Sievert POL fitting on the regulator? Or do I just need to scour the country for a cylinder and then go and visit friends near there to collect it! Any safe ideas welcome! Thanks.

I seem to remember last year post pandemic that there was a shortage of tanks along with building materials and everything else. I guess the situation hasn’t changed from what you say. Maybe you’ll just have to buy a cheap plumbers touch as I see Dennis suggested from B&Q (other hardware stores may be available in your area) until the situation resolves.

Green leisure cylinders are the same pressure, it's the regulators are no use for a Sievert. Fixed low pressure only.
If you can locate a dumped cylinder then you should be able to get that refilled. Whether or not that's feasible in your area is another matter - the large ones are often dumped by travellers around here.
Oh, and Calor are doing away with the smaller cylinder sizes imminently.

I hard from one of our local large suppliers that they are being charged double to maintain the smaller tanks, which is why they are being phased out. Its all because of EU regulations. Heavens knows what I'll be charged the next time I fill up mine.

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Originally Posted by HMM

Hi, Following your advice on a better torch for my casting, I’ve been bought a sievert torch to go on a propane cylinder. I now find that I can’t buy new cylinders near me from flogas or calor. They are only doing refills or green leisure cylinders (which I understand are low pressure and no use). Does anyone know of any other types of propane cylinder I can use, maybe with an adapter to fit the Sievert POL fitting on the regulator? Or do I just need to scour the country for a cylinder and then go and visit friends near there to collect it! Any safe ideas welcome! Thanks.

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Mine came from the local scrap merchant dealer - he had dozens even during lockdown. In fact he has so many he only charged for the gas and I got the tank free!