Silver will not melt!

Hi all sorry to post again but I’m so confused!
I have a propane/butane mix torch which gets up to 1300 degrees. I ordered some chemically refined fine silver and popped 13g of it into my crucible to melt with a pinch of flux once the crucible had heated up enough.
The silver begins to melt, it turns red and glows but then goes white and stodgy and no matter how long I keep the heat on it, it doesn’t get any more liquid enough for me to pour!
My torch melted silver before hand so I cannot fathom out why it’s not working?!
I have made sure to only use 100% silver as I worried last time I tried and it didn’t work was because I may have used something stamped 925 but may not have been. I don’t think that’s the issue now as the silver iv tried melting today is 999% pure but also won’t melt! Any advice please? Thank you

Temperature is not the same as heat. Everything you say points to the torch not providing enough heat for the quantity of metal.
Going on is not productive and exhausts the flux.
Try it with a small amount of metal and it will melt OK. Unless you change to a hotter torch altogether, two torches will double the heat output.
Also remember the hottest part of the flame is just outside the tip of the blue cone. Dennis.

Quote:

---

Originally Posted by Dennis

Temperature is not the same as heat. Everything you say points to the torch not providing enough heat for the quantity of metal.
Going on is not productive and exhausts the flux.
Try it with a small amount of metal and it will melt OK. Unless you change to a hotter torch altogether, two torches will double the heat output.
Also remember the hottest part of the flame is just outside the tip of the blue cone. Dennis.

---

Thanks Dennis, I tried to melt just 9g of silver but had the same issue. i would not melt. Can you recommend a torch that should give a sufficient heat to melt larger quantity of silver (20g ect)
Thank you!

No, something is decidedly wrong and for the moment I'm stuck. Maybe someone else will have the answer. Are you working somewhere draughty that cools it down? You need generous amounts of borax and when melted the surface of the metal appears to spin. Dennis.

Have you coated your crucible with borax to form a glass like finnish

Quote:

---

Originally Posted by china

Have you coated your crucible with borax to form a glass like finnish

---

Hi xx yes I had x

As said above all points to not enough heat, 20g is getting up there for a small butane torch, aside from using a hotter torch e.g. oxy/fuel gas are you able to build a small enclosure from insulating bricks even just three side sides will help retain the heat

Quote:

---

Originally Posted by Niamh

Thanks Dennis, I tried to melt just 9g of silver but had the same issue. i would not melt. Can you recommend a torch that should give a sufficient heat to melt larger quantity of silver (20g ect)
Thank you!

---

Hi,

I am not suggesting that the following setup is what you need, but it is the setup I use and never had a problem with casting. I have melted 30g (925) silver using the Sievert in the 2" Scorifier but now have a larger one I bought on eBay and have no problem melting 40 - 50g (925) silver with the same Sievert.

Also note: 999 Silver has a higher melting point than 925 Sterling silver!
Melting points: 999 Fine silver: 962°C | 925 Sterling silver: 893°C


My setup:

1. Torch: Sievert-Professional-Torch-Kit-prcode-999-AKZ1
2. Scorifier 2" Square:Scorifier-2-Square-prcode-999-AKP&query=999%20AKP&channel=uk
3. Burner: Sievert-Burner-3941-22mm-General-prcode-999-ALD&query=999%20ALD&channel=uk
4. Burner Neck (Needed to fit burner): Sievert-Neck-Tube-3511-prcode-999-ATY
5. I also bought the longer neck (3509) to keep my hand further away...(it got warm near the scorifier): http://www.cousinsuk.com/product/neck-tubes-sievert
6. Propane Gas: http://www.calor.co.uk/3-9kg-propane-gas-bottle.html

[QUOTE=handmadeblanks;99562]Hi,

I am not suggesting that the following setup is what you need, but it is the setup I use and never had a problem with casting. I have melted 30g (925) silver using the Sievert in the 2" Scorifier but now have a larger one I bought on eBay and have no problem melting 40 - 50g (925) silver with the same Sievert.

Also note: 999 Silver has a higher melting point than 925 Sterling silver!
Melting points: 999 Fine silver: 962°C | 925 Sterling silver: 893°C


Thank you handmadeblanks!
Because the Sievert torches are rather pricey and i cant afford them at the moment (Currently paying off things for our wedding in 3 months) I wondered if a Bernzomatic Propane % MAP gas torch might do the trick? It seems a bit more affordable at £50 from screwfix and iv been told MAP gas burns hotter then propane and butane.
I had built myself a little enclosure with fire bricks hoping to keep heat in but to no avail.
:( I dont want to give up im determined to do this!

Your £50 Bernzomatic is significantly less capable than this - https://gasproducts.co.uk/gas-blow-t...torch-kit.html (I have both...)
Up-front cost of gas will be higher, but the run time on the little cylinders is quite low, so it'll recoup fast.

Later, you can add more nozzles for different work. There's no need to go over to MAPP for melting small amounts of silver - air/propane is more than enough, although boxing in the heat is a worthwhile move.

Quote:

---

Originally Posted by ps_bond

Your £50 Bernzomatic is significantly less capable than this - https://gasproducts.co.uk/gas-blow-t...torch-kit.html (I have both...)
Up-front cost of gas will be higher, but the run time on the little cylinders is quite low, so it'll recoup fast.

Later, you can add more nozzles for different work. There's no need to go over to MAPP for melting small amounts of silver - air/propane is more than enough, although boxing in the heat is a worthwhile move.

---

Thank you Peter, Do you suggest getting a propane gas cylinder with this torch?

Quote:

---

Originally Posted by Niamh

Thank you handmadeblanks!
Because the Sievert torches are rather pricey and i cant afford them at the moment (Currently paying off things for our wedding in 3 months) I wondered if a Bernzomatic Propane % MAP gas torch might do the trick? It seems a bit more affordable at £50 from screwfix and iv been told MAP gas burns hotter then propane and butane.
I had built myself a little enclosure with fire bricks hoping to keep heat in but to no avail.
:( I dont want to give up im determined to do this!

---

There are cheaper Sievert Kits, like the one ps_bond recommends or this one: https://www.machinemart.co.uk/p/pmpx...nal-torch-kit/

The burner on this kit is 7.7Kw which is more than enough as the burner I use on my kit is 3.1Kw

I have not used MAPP but I have seen Youtube video's of people melting silver with MAPP. ps_bond is better qualified to answer as he has both.

I'm not sure if you would end up saving much buying the disposable...it might be worth saving for the Sievert because it will definitely work.

Yes, use propane!

One of the dinky ones will last a fair time - the 3.9kg ones. Light enough to be managed easily (with an easy carrying handle).

The usual disposable ones are 400g at around £12; 9.75 of them will give around the same volume of gas. A 3.9kg cylinder will cost £56.54 from Calor as a first buy, then £16.55 per refill.
https://www.calor.co.uk/shop/gas-bot...as-bottle.html

Or you can go larger :)

Quote:

---

Originally Posted by handmadeblanks

I have not used MAPP but I have seen Youtube video's of people melting silver with MAPP. ps_bond is better qualified to answer as he has both.

---

MAPP's too expensive to use it as a standard thing IMO - I only resort to it when I absolutely need to. Most of the time my need for more heat is satisfied by the Sievert instead of the dinky one.
For stuff that's too large for the Sievert I use the Flamefast torch.

Quote:

---

Originally Posted by ps_bond

MAPP's too expensive to use it as a standard thing IMO - I only resort to it when I absolutely need to. Most of the time my need for more heat is satisfied by the Sievert instead of the dinky one.
For stuff that's too large for the Sievert I use the Flamefast torch.

---

Thank you everyone, I found a sievert Po 86 propane gas blow torch brand new on ebay for £60. Is this a good buy do you think? Id be buying a propane cylinder to accompany it from screwfix as i wont be doing much melting just yet as im only just starting out on the venture to make my wedding ring. Thankyou

Quote:

---

Originally Posted by ps_bond

One of the dinky ones will last a fair time - the 3.9kg ones. Light enough to be managed easily (with an easy carrying handle).

The usual disposable ones are 400g at around £12; 9.75 of them will give around the same volume of gas. A 3.9kg cylinder will cost £56.54 from Calor as a first buy, then £16.55 per refill.
https://www.calor.co.uk/shop/gas-bot...as-bottle.html

Or you can go larger :)

---

You can get a rough idea of how long 3.9Kg will last.

The burner I use is rated at 240g/h @ 2Bar

This means that I can run it continually for approx 16.25 hours

Given that the average casting takes 5 minutes, I can do approx 195 castings...(If I've done my maths right)

I have had mine for well over a year and although I don't do much casting now, I have done at least 20 - 30 castings, at least that many ingots and countless annealing and it still isn't empty!

I don't think Screwfix do POL fitting gas cylinders... I'll check.

...Nope, thought not.

The cylinders that Screwfix sell will only work on the Rothenberger/Bernzomatic-type torches. You need a proper POL fitting propane bottle to use with the Sievert. Calor (as one gas supplier) will list suppliers near you.

As for EBay, make sure it is genuine.

Quote:

---

Originally Posted by ps_bond

I don't think Screwfix do POL fitting gas cylinders... I'll check.

---

No your right they dont do them! Calor gas is my best bet in that case im lucky to have a calor gas place local to me. I paid £50 for the Seivert torch in the end so im quite chuffed.

Hi Niamh, have you tried with new dilver? I had a similar problem. An old jewel was made from an old silver Dutch guilder. But this is never 100% silver and the additions caused the problems. I would in any case use a different melting tray.
Good luck,

Verstuurd vanaf mijn GT-N8010 met Tapatalk

Quote:

---

Originally Posted by mariannez

Hi Niamh, have you tried with new dilver? I had a similar problem. An old jewel was made from an old silver Dutch guilder. But this is never 100% silver and the additions caused the problems. I would in any case use a different melting tray.
Good luck,

Verstuurd vanaf mijn GT-N8010 met Tapatalk

---

Thanks Mariannez, I have tried with new silver last night (sheet silver i had been given by a jeweler friend) it did melt in small quantity's but the moment i tried to add a bit more so i could cast my ring it failed to melt anymore so i think everyone saying my torch isnt hot enough is right. I have bought a Sievert Pro 86 Propane Gas Blow Torch Kit so im hopeful this will work!

One thing iv been noticing though is when my silver cools and solidifies its got a blue shiney coating on the bottom half where its cooled in the crucible? looks like blue enamel but theres been nothing blue added to the silver? just sheet silver and Borax?

That's the discolouration due to heating, with a borax glaze. It would come off after 5 minutes in hot pickle.

am a real newbie with a melt problem. Am using oxy/propane in an 80mm melting dish. I can obtain the rolling ball and maintain it for 30 sec etc but asoon as the silver is out of the dish it wants to solidify. I have attempted the cast a dozen times and wonder if the nature of the silver has changed .It began as 50/50 925 and 999. V graqteful for guidance

jemd

This is a common complaint, because it requires a lot of heat when pouring silver.

Use powdered borax as flux, keep the flame on the silver when pouring, dont take it off.

If this doesn't work your torch is too cool. Use a bigger burner for your torch, or a bigger torch. Dennis.

Thanks DEnnis,
will try full blast